Search

Background: Ataxia telangiectasia (AT) is a genetic multisystemic disorder affecting the nervous system. Data on neurocognitive functioning in AT are limited and focused on patients at various stages of disease. Because of the genetic nature of the disorder, parents of patients may also display subtle neurological problems. This study aimed to evaluate neurocognitive functioning in patients with AT and their unaffected parents., Methods: The study included 26 patients with AT and 41 parents among which 13 patients and 18 parents were evaluated with neurocognitive tests. Clinical and radiological data were reviewed retrospectively. Data were analyzed with descriptive statistics., Results: The median ages of patients and parents were 12.5 years (interquartile range [IQR] = 9.5) and 38.0 years (IQR = 12.0), respectively. Median intelligence quotients were 62.0 (IQR = 21.3) and 82.5 (IQR = 16.8), respectively, for patients and parents. Rates of intellectual disability for patients and parents were 100.0% and 83.3%, respectively. Areas of impairment in patients in decreasing order of frequency were motor skills, visual perception/memory, visual-manual coordination, spontaneous/focused and sustained attention (100.0% for each), social judgment, as well as vocabulary and arithmetic skills (75.0% for each). Areas of impairment in unaffected parents in decreasing order of frequency were visual-manual coordination (77.8%), working memory (76.5%), and visual perception and motor skills (66.7% for each)., Conclusion: Intellectual disabilities, visual-spatial disabilities, and reduced visual-motor coordination seem to be similar in patients with AT and their parents. These results should be replicated with larger samples from multiple centers and may form putative cognitive endophenotypes for the disorder., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Emel Uyar reports financial support was provided by Marmara University. The other authors declare that they have no other competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Ataxia Telangiectasia (A-T) and Ataxia with Ocular Apraxia Type 1 (AOA1) are devastating neurological disorders caused by null mutations in the genome stability genes, A-T mutated ( ATM ) and Aprataxin ( APTX ), respectively. Our mechanistic understanding and therapeutic repertoire for treating these disorders are severely lacking, in large part due to the failure of prior animal models with similar null mutations to recapitulate the characteristic loss of motor coordination (i.e., ataxia) and associated cerebellar defects. By increasing genotoxic stress through the insertion of null mutations in both the Atm (nonsense) and Aptx (knockout) genes in the same animal, we have generated a novel mouse model that for the first time develops a progressively severe ataxic phenotype associated with atrophy of the cerebellar molecular layer. We find biophysical properties of cerebellar Purkinje neurons (PNs) are significantly perturbed (e.g., reduced membrane capacitance, lower action potential [AP] thresholds, etc.), while properties of synaptic inputs remain largely unchanged. These perturbations significantly alter PN neural activity, including a progressive reduction in spontaneous AP firing frequency that correlates with both cerebellar atrophy and ataxia over the animal's first year of life. Double mutant mice also exhibit a high predisposition to developing cancer (thymomas) and immune abnormalities (impaired early thymocyte development and T-cell maturation), symptoms characteristic of A-T. Finally, by inserting a clinically relevant nonsense-type null mutation in Atm , we demonstrate that S mall M olecule R ead- T hrough (SMRT) compounds can restore ATM production, indicating their potential as a future A-T therapeutic., Competing Interests: HP, MA, JC, AN, ME, KV, CB, VS, JK, MP, KN, GH, RG, JM, MI, PM, PM No competing interests declared, (© 2021, Perez et al.)

Introduction: Besides cerebellar ataxia, various other movement disorders, including dystonia, could manifest as main clinical symptoms in ataxia-telangiectasia (A-T). However, the clinical characteristics of dystonic A-T patients are not clearly elucidated., Methods: To investigate the characteristics of dystonic A-T, we screened previous reports with A-T patients presenting dystonia as a main manifestation, and included 38 dystonic A-T patients from 16 previous studies and our 2 cases. We reviewed clinical and demographic data of dystonic A-T patients. Additionally, to figure out clinical meaning of cerebellar involvement in dystonic A-T, we divided them into two groups based on the presence of cerebellar involvement, and compared clinical features between two groups., Results: In the patients with dystonic A-T, dystonia tended to appear during childhood or adolescence and became generalized over time. Choreoathetosis and myoclonus accompanied more frequently than the typical clinical features, including cerebellar ataxia or atrophy, telangiectasia, or oculomotor apraxia. Additionally, alpha-fetoprotein level was also elevated in the patients with dystonic A-T. When we compared dystonic A-T with and without cerebellar involvement, the former was related with more chance for telangiectasia and oculomotor apraxia, while the latter with that for choreoathetosis and malignancy., Conclusion: Even without ataxia, telangiectasia, or oculomotor apraxia, A-T should be considered in undiagnosed dystonia, especially generalized dystonia which started from childhood or adolescence period, and alpha-fetoprotein level can be a useful screening tool. In addition, cerebellar involvement is important considering different phenotype in dystonic A-T patients with and without cerebellar sign., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Objectives: With disease-modifying drugs on the horizon for degenerative ataxias, ecologically valid motor biomarkers are highly warranted. In this observational study, we aimed to unravel and validate markers of ataxic gait in real life by using wearable sensors., Methods: We assessed gait characteristics of 43 patients with degenerative cerebellar disease (Scale for the Assessment and Rating of Ataxia [SARA] 9.4 ± 3.9) compared with 35 controls by 3 body-worn inertial sensors in 3 conditions: (1) laboratory-based walking; (2) supervised free walking; (3) real-life walking during everyday living (subgroup n = 21). Movement analysis focused on measures of spatiotemporal step variability and movement smoothness., Results: A set of gait variability measures was identified that allowed us to consistently identify ataxic gait changes in all 3 conditions. Lateral step deviation and a compound measure of spatial step variability categorized patients vs controls with a discrimination accuracy of 0.86 in real life. Both were highly correlated with clinical ataxia severity (effect size ρ = 0.76). These measures allowed detecting group differences even for patients who differed only 1 point in the clinical SARA posture&gait subscore, with highest effect sizes for real-life walking ( d = 0.67)., Conclusions: We identified measures of ataxic gait that allowed us not only to capture the gait variability inherent in ataxic gait in real life, but also to demonstrate high sensitivity to small differences in disease severity, with the highest effect sizes in real-life walking. They thus represent promising candidates for motor markers for natural history and treatment trials in ecologically valid contexts., Classification of Evidence: This study provides Class I evidence that a set of gait variability measures, even if accessed in real life, correlated with the clinical severity of ataxia in patients with degenerative cerebellar disease., (© 2020 American Academy of Neurology.)

Aim: To collect preliminary functional data on ataxia telangiectasia and create a disease specific scale: the Ataxia Telangiectasia Functional Scale (ATFS)., Method: Retrospective information on patients with ataxia telangiectasia referred to the Assistive Technology Unit was included. Functional mobility scales (the Gross Motor Function Classification System [GMFCS] and the Functional Mobility Scale [FMS]-5, FMS-50, FMS-500) and activities of daily living [ADL] parameters were recorded. We created a 51-point ATFS, that consisted of three ambulation items adapted for ataxia telangiectasia in the frame of FMS (home, school, outdoors), five ADL items, and one schooling item., Results: Twenty-seven participants (17 males, 10 females; mean age 10y 8mo [SD 5y 1mo], range 1y 9mo-25y 6mo), were enrolled; 168 measurements were recorded. Patients walked at a mean age of 1 year 4 months (SD 5y 4mo) and lost ambulatory capacity at 8 years 8 months (SD 2y 1mo). GMFCS level and FMS-5, FMS-50, FMS-500 assessments correlated with age (Spearman's correlations r=0.555, -0.617, -0.639, -0.662 respectively, p<0.01 for all), but plateaued after 12 years of age. ATFS mean score was 37.46 (SD 7.88) and increased with age (Spearman's correlation r=0.585, p<0.01). The scale showed three stages of disease progression., Interpretation: In this pilot study we show longitudinal functional data of ambulation and ADL skills in ataxia telangiectasia, and created a framework for a functional scale. This functional scale closely approximated disease course, but further validation is required., What This Paper Adds: The Gross Motor Function Classification System and the Functional Mobility Scale are ill-suited for ataxia telangiectasia assessments. Three functional mobility scales (home, school, outdoors) suited to ataxia telangiectasia were created. The Ataxia Telangiectasia Functional Scale (ATFS) combines mobility and items of activities of daily living. The ATFS closely approximates the three-stage progression of the disorder., (© 2019 Mac Keith Press.)

Background: Ataxia Telangiectasia (A-T) is an inherited multisystem disorder with cerebellar neurodegeneration. The relationships between imaging metrics of cerebellar health and neurological function across childhood in A-T are unknown, but may be important for determining timing and impact of therapeutic interventions., Purpose: To test the hypothesis that abnormalities of cerebellar structure, physiology and cellular health occur in childhood A-T and correlate with neurological disability, we performed multiparametric cerebellar MRI and establish associations with disease status in childhood A-T., Methods: Prospective cross-sectional observational study. 22 young people (9 females / 13 males, age 6.6-17.8 years) with A-T and 24 matched healthy controls underwent 3-Tesla MRI with volumetric, diffusion and proton spectroscopic acquisitions. Participants with A-T underwent structured neurological assessment, and expression / activity of ataxia-telangiectasia mutated (ATM) kinase were recorded., Results: Ataxia-telangiectasia participants had cerebellar volume loss (fractional total cerebellar volume: 5.3% vs 8.7%, P < 0.0005, fractional 4th ventricular volumes: 0.19% vs 0.13%, P < 0.0005), that progressed with age (fractional cerebellar volumes, r = -0.66, P = 0.001), different from the control group (t = -4.88, P < 0.0005). The relationship between cerebellar volume and age was similar for A-T participants with absent ATM kinase production and those producing non-functioning ATM kinase. Markers of cerebellar white matter injury were elevated in ataxia-telangiectasia vs controls (apparent diffusion coefficient: 0.89 × 10 -3  mm 2  s -1 vs 0.69 × 10 -3  mm 2  s -1 , p < 0.0005) and correlated (age-corrected) with neurometabolite ratios indicating impaired neuronal viability (N-acetylaspartate:creatine r = -0.70, P < 0.001); gliosis (inositol:creatine r = 0.50, P = 0.018; combined glutamine/glutamate:creatine r = -0.55, P = 0.008) and increased myelin turnover (choline:creatine r = 0.68, P < 0.001). Fractional 4th ventricular volume was the only variable retained in the regression model predicting neurological function (adjusted r 2  = 0.29, P = 0.015)., Conclusions: Quantitative MRI demonstrates cerebellar abnormalities in children with A-T, providing non-invasive measures of progressive cerebellar injury and markers reflecting neurological status. These MRI metrics may be of value in determining timing and impact of interventions aimed at altering the natural history of A-T., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Ataxia-telangiectasia is a multi-system disorder in which neurologic impairment and immune deficiency are observed. In the present study, patients with ataxia-telangiectasia were followed to provide information regarding clinical and immunological features., Methods: We report a case series of 18 patients diagnosed with ataxia-telangiectasia, who were referred to a tertiary center of clinical immunology from 2008-2018. Clinical presentations, medical records and lab data were observed during this period with a mean follow-up time of 4.57 ± 2.66 years., Results: The mean age of the patients was 10.92 ± 3.24 years (11 females and 7 males). Thirteen patients (72.22%) were from families with consanguinity. Ataxia was the most common clinical feature, observed in 18 (100%) patients. The predominant clinical presentations were tremor and oculocutaneous telangiectasia, observed in 14 (77.8%) patients; dysarthria and oculomotor apraxia, observed in 13 (72.2%) patients. Infections were recorded in 12 (70.6%) patients. Decreased IgG level and IgA levels were observed in 5 (33.3%) and 6 (40.0%) patients, respectively. Decreased B-cell number and T-cell number were noted in 7 (46.67%) and 11 (73.33%) patients, respectively. Three (16.7%) patients were diagnosed with acute lymphoblastic leukemia and two of them expired subsequently., Conclusion: Ataxia-telangiectasia is a progressive disease with no established therapy; so, it necessitates early diagnosis and follow-up of the patients. The presented clinical and immunological data in this study may help with diagnosis and management of the disease complications., (© 2019 The Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.)

Fanconi anaemia (FA), ataxia telangiectasia (A-T), Nijmegen breakage syndrome (NBS) and Bloom syndrome (BS) are clinically distinct, chromosome instability (or breakage) disorders. Each disorder has its own pattern of chromosomal damage, with cells from these patients being hypersensitive to particular genotoxic drugs, indicating that the underlying defect in each case is likely to be different. In addition, each syndrome shows a predisposition to cancer. Study of the molecular and genetic basis of these disorders has revealed mechanisms of recognition and repair of DNA double-strand breaks, DNA interstrand crosslinks and DNA damage during DNA replication. Specialist clinics for each disorder have provided the concentration of expertise needed to tackle their characteristic clinical problems and improve outcomes. Although some treatments of the consequences of a disorder may be possible, for example, haematopoietic stem cell transplantation in FA and NBS, future early intervention to prevent complications of disease will depend on a greater understanding of the roles of the affected DNA repair pathways in development. An important realization has been the predisposition to cancer in carriers of some of these gene mutations.

Ataxia-telangiectasia is the second most common autosomal recessive hereditary ataxia, with an estimated incidence of 1 in 100,000 births. Besides ataxia and ocular telangiectasias, eye movement abnormalities have long been associated with this disorder and is frequently present in almost all patients. A handful of studies have described the phenomenology of ocular motor deficits in ataxia-telangiectasia. Contemporary literature linked their physiology to cerebellar dysfunction and secondary abnormalities at the level of brainstem. These studies, while providing a proof of concept of ocular motor physiology in disease, i.e., ataxia-telangiectasia, also advanced our understanding of how the cerebellum works. Here, we will summarize the clinical abnormalities seen with ataxia-telangiectasia in each subtype of eye movements and subsequently describe the underlying pathophysiology. Finally, we will review how these deficits are linked to abnormal cerebellar function and how it allows better understanding of the cerebellar physiology.

The term "cerebral palsy mimic" is used to describe a number of neurogenetic disorders that may present with motor symptoms in early childhood, resulting in a misdiagnosis of cerebral palsy. Cerebral palsy describes a heterogeneous group of neurodevelopmental disorders characterized by onset in infancy or early childhood of motor symptoms (including hypotonia, spasticity, dystonia, and chorea), often accompanied by developmental delay. The primary etiology of a cerebral palsy syndrome should always be identified if possible. This is particularly important in the case of genetic or metabolic disorders that have specific disease-modifying treatment. In this article, we discuss clinical features that should alert the clinician to the possibility of a cerebral palsy mimic, provide a practical framework for selecting and interpreting neuroimaging, biochemical, and genetic investigations, and highlight selected conditions that may present with predominant spasticity, dystonia/chorea, and ataxia. Making a precise diagnosis of a genetic disorder has important implications for treatment, and for advising the family regarding prognosis and genetic counseling. © 2019 International Parkinson and Movement Disorder Society., (© 2019 International Parkinson and Movement Disorder Society.)

Ataxia‑telangiectasia (A‑T) is an autosomal recessive chromosome breakage disorder caused by mutations in the ATM serine/threonine kinase (ATM) gene. Typically, it presents in early childhood with progressive cerebellar dysfunction, accompanied by immunodeficiency and oculocutaneous telangiectasia. In the present study, the clinical and genetic findings of a Chinese family affected with A‑T in two live siblings, the proband (II‑2) and his elder brother (II‑1), as well as a fetus (II‑3) were reported. General health, clinical neurological, electrophysiological (motor and sensory nerve conduction) and magnetic resonance imaging evaluations revealed that patients II‑1 and II‑2 had similar symptoms of ataxia, dysarthria, conjunctival hyperemia and elevated serum α‑fetoprotein, whereas patient II‑1 had earlier A‑T onset at 2 years old and more serious problems with movement and intelligence. Targeted sequencing followed by Sanger sequencing revealed that these two patients carried the compound heterozygotes of a novel nonsense mutation c.5170G>T (p.Glu1724Ter) and a known nonsense mutation c.748C>T (p.Arg250Ter) in the ATM gene. Each mutation was inherited from an asymptomatic parent, which therefore confirmed the diagnosis of A‑T. Given this, proband's mother performed prenatal diagnosis in her third pregnancy. Unfortunately, the fetus had the same causal mutations as its siblings and the pregnancy was terminated. The findings of the present study expanded the mutation spectrum of the ATM gene and may help in understanding the genetic basis of A‑T, in order to guide genetic counseling and prenatal diagnosis.

Ataxia telangiectasia is a rare, multi system disease caused by ATM kinase deficiency. Atm -knockout mice recapitulate premature aging, immunodeficiency, cancer predisposition, growth retardation and motor defects, but not cerebellar neurodegeneration and ataxia. We explored whether Atm loss is responsible for skeletal muscle defects by investigating myofiber morphology, oxidative/glycolytic activity, myocyte ultrastructural architecture and neuromuscular junctions. Atm -knockout mice showed reduced muscle and fiber size. Atrophy, protein synthesis impairment and a switch from glycolytic to oxidative fibers were detected, along with an increase of in expression of slow and fast myosin types ( Myh7 , and Myh2 and Myh4 , respectively) in tibialis anterior and solei muscles isolated from Atm -knockout mice. Transmission electron microscopy of tibialis anterior revealed misalignments of Z-lines and sarcomeres and mitochondria abnormalities that were associated with an increase in reactive oxygen species. Moreover, neuromuscular junctions appeared larger and more complex than those in Atm wild-type mice, but with preserved presynaptic terminals. In conclusion, we report for the first time that Atm-knockout mice have clear morphological skeletal muscle defects that will be relevant for the investigation of the oxidative stress response, motor alteration and the interplay with peripheral nervous system in ataxia telangiectasia., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2019. Published by The Company of Biologists Ltd.)

The number of primary immune deficiencies exceeds 350, approximately a quarter of them having neurological implications. Severe central nervous system infections may occur in an even higher proportion. Beyond listing in a table of all diseases with a neurological impact, the author gives detailed analysis of one typical disorder. Ataxia telangiectasia is caused by biallelic mutation of the ATM gene resulting in genomic instability, increased cancer risk, immune deficiency and a predominantly cerebellar neurodegeneration. The most common classic form is characterized by gait and limb ataxia, oculomotor apraxia, choreoathetosis, disturbance of speech and swallowing, less often by other movement disorders. There is no remarkable cognitive deficit. Telangiectasia of the conjunctivae and skin usually appears after 6 years of age. Frequent, especially severe sino-pulmonary infections may indicate the immune deficiency present in 60 to 80% of patients, who are also prone to malignancies. The clinical course is sometimes atypical or has a late onset which results in diagnostic difficulties. Serum alpha-fetoprotein level is elevated in nearly all patients. Brain MRI shows progressive cerebellar atrophy starting at the age of 7-8 years. DNA testing of the ATM gene is necessary for the diagnosis. The detected biallelic pathogenic variants provide help for family planning and for possible gene therapies in the future. Ataxia telangiectasia has to be differentiated from a number of other disorders, some of which also belong to primary immune deficiencies. The disorder has no causal treatment at present, the patients live until their young adult ages. Orv Hetil. 2018; 159(49): 2057-2064.

Background: Inflammation plays a critical role in accelerating the progression of neurodegenerative diseases, such as Alzheimer's disease (AD) and ataxia telangiectasia (A-T). In A-T mouse models, LPS-induced neuroinflammation advances the degenerative changes found in cerebellar Purkinje neurons both in vivo and in vitro. In the current study, we ask whether ibuprofen, a non-steroidal anti-inflammatory drug (NSAID), can have the opposite effect and delay the symptoms of the disease., Methods: We tested the beneficial effects of ibuprofen in both in vitro and in vivo models. Conditioned medium from LPS stimulated primary microglia (LM) applied to cultures of dissociated cortical neurons leads to numerous degenerative changes. Pretreatment of the neurons with ibuprofen, however, blocked this damage. Systemic injection of LPS into either adult wild-type or adult Atm -/- mice produced an immune challenge that triggered profound behavioral, biochemical, and histological effects. We used a 2-week ibuprofen pretreatment regimen to investigate whether these LPS effects could be blocked. We also treated young presymptomatic Atm -/- mice to determine if ibuprofen could delay the appearance of symptoms., Results: Adding ibuprofen directly to neuronal cultures significantly reduced LM-induced degeneration. Curiously, adding ibuprofen to the microglia cultures before the LPS challenge had little effect, thus implying a direct effect of the NSAID on the neuronal cultures. In vivo administration of ibuprofen to Atm -/- animals before a systemic LPS immune challenge suppressed cytological damage. The ibuprofen effects were widespread as microglial activation, p38 phosphorylation, DNA damage, and neuronal cell cycle reentry were all reduced. Unfortunately, ibuprofen only slightly improved the LPS-induced behavioral deficits. Yet, while the behavioral symptoms could not be reversed once they were established in adult Atm -/- animals, administration of ibuprofen to young mutant pups prevented their symptoms from appearing., Conclusion: Inflammatory processes impact the normal progression of A-T implying that modulation of the immune system can have therapeutic benefit for both the behavioral and cellular symptoms of this neurodegenerative disease.

Nuclear factor (erythroid-derived 2)-like factor 2 (NFE2L2, formerly Nrf2) is a transcription factor that binds to the antioxidant response element (ARE) in the upstream promoter region of various antioxidant-responsive genes. Hence, at least in nonruminants, the NFE2L2-ARE signaling pathway plays an important role in the cellular antioxidant defense system. Whether oxidative stress in bovine mammary epithelial cells alters NFE2L2 or the NFE2L2-ARE pathway is unclear. Therefore, the objective of this study was to examine the response in NFE2L2- and NFE2L2-ARE-related components in bovine mammary epithelial cells (BMEC) under oxidative stress. An in silico analysis to identify potential phosphorylation sites on NFE2L2 and the protein kinases was performed with Netphos 3.1 (http://www.cbs.dtu.dk/services/NetPhos/) and Scansite (http://scansite.mit.edu) software. Isolated BMEC were exposed to H 2 O 2 (600 μM) for 6 h to induce oxidative stress. In silico analysis revealed ataxia telangiectasia-mutated (ATM) serine/threonine kinase as a key kinase responsible for the phosphorylation of NFE2L2. Thus, after the 6 h incubation with H 2 O 2 , BMEC were transiently transfected with ATM-small interfering RNA (siRNA) 1, 2, or 3. Compared with the control, transfection with ATM-siRNA3 resulted in proliferation rates that were 60.7 and 36.2% lower with or without H 2 O 2 . In addition, production of reactive oxygen species and malondialdehyde increased markedly, but activities of superoxide dismutase, glutathione peroxidase, catalase, and glutathione-S-transferase decreased markedly in transfected cells without or with H 2 O 2 compared with the control. Transfected cells had markedly lower protein and mRNA expression of NFE2L2 without or with H 2 O 2 compared with the control. In addition, fluorescent activity of the ARE in transfected BMEC indicated that NFE2L2-driven transcriptional activation decreased under oxidative stress. Overall, results indicate that ATM is a physiologically relevant NFE2L2 kinase. Furthermore, inhibition of ATM activity can cause marked alterations in oxidative stress leading to cell death as a result of diminished capacity of BMEC to cope with H 2 O 2 -induced cytotoxicity. The relevance of this kinase in vivo merits further study., (Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

Objective: Ataxia telangiectasia (A-T) is a rare genetic disease involving multiple organs, but, to our knowledge, data on long-term gastrointestinal and nutritional involvement are scarce. The aim of this study was to longitudinally review the nutritional and gastrointestinal aspects of A-T., Methods: This was a retrospective chart review of patients followed from 1986 to 2015 at one center. Demographic, laboratory, and nutritional data were retrieved. Body mass index (BMI) values were converted to BMI Z-score (BMI-Z). Caloric intake was estimated by food diaries and compared with estimated energy requirements for sex and age with a physical activity level factor for light physical activity., Results: The study included 53 patients (28 males [53%], ages 14.6 ± 5.2 y). BMI-Z was inversely correlated with age (r = 0.48; P < 0.004). A decline below minimal BMI percentiles was observed after the age of 4 y in boys and 7 y in girls. The relative percentage of caloric intake decreased with age (r = -0.5; P < 0.002), and was positively correlated with BMI-Z (r = 0.35; P < 0.05). Presence of cough during meals was associated with recurrent lower respiratory tract infections (Fisher exact test, P < 0.01). Gastrostomy tubes were inserted in 12 patients, leading to improvement in BMI-Z from -5.1 ± 2.4 to -4 ± 2.9 (P < 0.05)., Conclusions: There is a progressive growth failure and low nutritional intake with age in patients with A-T, starting in early childhood in males, and more prominent in patients with cough and choking during meals. A proactive approach and insertion of a percutaneous gastrostomy tube as soon as the BMI-Z starts to decrease should be considered., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Ataxia-telangiectasia (AT) is a rare autosomal recessive neurodegenerative disease caused by mutations in the ATM gene with progressive neurological dysfunction, multisystem abnormalities and cancer predisposition. Classically, AT is associated with cerebellar ataxia, oculocutaneous telangiectasia and oculomotor apraxia. The aim of this review is to describe the movement disorders observed in patients with AT. Movement disorders in AT patients described in the literature are reviewed. The selected articles were analyzed with a focus on clinical presentation, presence of movement disorders, and atypical cases or variants of the syndrome. In AT patients, particularly adults, chorea and dystonia are the most common movement disorders, besides cerebellar ataxia. Myoclonus, tremor and parkinsonism have been described less frequently in patients with AT. Archetypal findings, such as oculocutaneous abnormalities may not be uniformly present. AT can present with different movement disorders, in isolation or combined, with or without cerebellar ataxia or oculocutaneous telangiectasias. Neurologists with expertise in movement disorders should be aware of AT when investigating patients with movement disorders of unknown etiology., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Background: Ataxia telangiectasia (A-T) is a neurodegenerative disease that leads to mitochondrial dysfunction and oxidative stress. Insulin resistance (IR), type 2 diabetes and the risk for development of cardiovascular disease was recently associated as an extended phenotype of the disease. We aimed to assess IR; liver involvement; carotid intima-media thickness (cIMT) and metabolic alterations associated to cardiovascular risk in A-T patients, and relate them with age., Results: Glucose metabolism alterations were found in 54.6% of the patients. Hepatic steatosis was diagnosed in 11/17 (64.7%) A-T patients. AST/ALT ratio > 1 was observed in 10/17 (58.8%). A strong positive correlation was observed between insulin sum concentrations with ALT (r = 0.782, p < 0.004) and age (r = 0.818, p = 0.002). Dyslipidemia was observed in 55.5% of the patients. The apolipoprotein (Apo-B)/ApoA-I ratio (r = 0.619; p < 0.01), LDL/HDL-c (r = 0.490; p < 0.05) and the Apo-B levels (r = 0.545; p < 0.05) were positively correlated to cIMT., Conclusions: Metabolic disorders implicated in cardiovascular and liver diseases are frequently observed in adolescent A-T patients and those tend to get worse as they become older. Therefore, nutritional intervention and the use of drugs may be necessary.

Ataxia-telangiectasia is a chronic progressive disorder affecting the nervous and immune systems, caused by a genetic defect in the ATM protein. Clasmatodendrosis, a distinct form of astroglial death, has rarely been reported in ataxia-telangiectasia. Neuropathology of our patient disclosed diffuse edema of the cerebral and cerebellar white matter with prominent clasmatodendrosis, implicating ATM in the regulation of astroglial cell death., (Copyright © 2017 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)

BACKGROUND The body of literature on oral motor and swallowing disorders in patients with ataxia telangiectasia (AT) is limited. CASE REPORT The purpose of this study was to characterize oral motor and swallowing disorders in two siblings with AT, based on oral motor and swallowing assessments. Specific procedures were applied for oral motor and swallowing assessments and both patients underwent videofluoroscopy (VFS). Case 1 presented vocal instability, change in postural control during feeding; food retention in oral cavity; slower oral transit time; and multiple swallowing (signs for solid and liquid). Case 2 presented parted lips at rest and reduced muscle strength; reduced strength and mobility of the tongue; vocal weakness and instability; reduced speech precision and intelligibility; decreased intonation pattern; food retention in oral cavity during feeding; slower oral transit time; multiple swallowing (signs for solid and liquid); poor bolus ejection; incoordination and difficulty in controlling the sips of water taken from the cup; altered cervical auscultation after swallowing and respiratory distress (liquid and puree). For both patients VFS results revealed laryngeal penetration for liquid. CONCLUSIONS Although the literature describes the occurrence of dysarthria and swallowing disorders in patients with AT, little attention has been given to describing which oral motor deficits are responsible for these disorders. Early identification of swallowing alterations and rehabilitation could decrease the risk of aspiration pneumonia. Future studies are necessary in order to investigate the deterioration process of swallowing in AT and the influence of rehabilitation in maintaining functional health.

This article explores three neurocutaneous syndromes (NCSs), i.e. genetic disorders producing developmental abnormalities of the skin and an increased risk of neurological complications. In this review, different aspects of ataxia telangiectasia, Menkes kinky hair disease and neurocutaneous melanosis are examined: clinical features, genetic defect, mutation spectrum, pathogenesis, and neurobiological basis; indications for clinical practice are also provided to the readers. The aim of this review is to stress the importance of cooperation among dermatologists, neurologists and psychiatrists, in order to provide patients suffering from these diseases with timely diagnosis and targeted treatments.

A-T is a prototype genome instability syndrome and a multifaceted disease. A-T leads to neurodegeneration - primarily cerebellar atrophy, immunodeficiency, oculocutaneous telangiectasia (dilated blood vessels), vestigial thymus and gonads, endocrine abnormalities, cancer predisposition and varying sensitivity to DNA damaging agents, particularly those that induce DNA double-strand breaks. With the recent increase in life expectancy of A-T patients, the premature ageing component of this disease is gaining greater awareness. The complex A-T phenotype reflects the ever growing number of functions assigned to the protein encoded by the responsible gene - the homeostatic protein kinase, ATM. The quest to thoroughly understand the complex A-T phenotype may reveal yet elusive ATM functions., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Aim: To assess peripheral and central hearing in children with A-T., Method: 3 children diagnosed with A-T according to the diagnostic criteria for A-T of the European Society for Immunodeficiencies. Involuntary movements were seen in the form of chorea-athetosis together with tremors. They were examined to assess both peripheral and central hearing was assessed (hearing thresholds). Sound-field testing, tympanometry, acoustic reflexes, Otoacoustic Emissions (OAEs) and Auditory Brainstem Responses (ABR) were done for all of them., Results: Basic Audiological evaluation is of a limited value as the children are not co-operative. Sound field testing could not be done. Bilateral normal middle ear functions as reflected by Tympanometry and Acoustic Reflexes. Advanced Audiological evaluation including OAEs and ABR are more valuable in assessing hearing in children with A-T. Bilateral pass response at all test frequencies in DPOAEs. Abnormal ABR findings were obtained in the form of a delay in wave V latency more than 2 SD with subsequent increased in I-V interpeak latency with no significant interaural latency difference., Conclusion: Consistent with bilateral normal peripheral hearing sensitivity with central hearing affection., Limitations: The rarity of the disease, make it difficult to be applied on many cases., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

ATM is a master regulator of the cellular response to DNA damage. The classical mechanism of ATM activation involves its monomerization in response to DNA double-strand breaks, resulting in ATM-dependent phosphorylation of more than a thousand substrates required for cell cycle progression, DNA repair, and apoptosis. Here, new experimental evidence for non-canonical mechanisms of ATM activation in response to stimuli distinct from DNA double-strand breaks is discussed. It includes cytoskeletal changes, chromatin modifications, RNA-DNA hybrids, and DNA single-strand breaks. Noncanonical ATM activation may be important for the pathology of the multisystemic disease Ataxia Telangiectasia.

Aim: To assess the relationship between genotype and neurological progression in ataxia-telangiectasia (A-T)., Methods: Clinical and laboratory data were extracted retrospectively from the records of patients attending the UK National Ataxia-Telangiectasia Clinic. Neurological assessments were performed using the A-T Index (Crawford Score) and the A-T Neurological Examination Scale Toolkit (A-T NEST). Variables influencing phenotype were identified by using an information-theoretic approach starting from a maximal model to generate estimates of coefficients for each variable. Per-individual progression was assessed for patients with three or more clinic attendances., Results: The genotype could be determined for 125/135 patients. Crawford and A-T NEST scores were well correlated. For both scoring systems the estimated coefficients were significantly positive for Age x kinase activity but not Age x protein expression. Unlike the per-genotype analysis, the individual progression of neurological scores in the 34 patients that attended on three or more occasions was not smooth and linear (and in some cases improved over time)., Interpretation: Residual kinase activity confers a milder phenotype but there is no difference between kinase-dead and protein-null genotypes. The non-linear progression of individual patients' neurological scores may reflect biological complexity, day-to-day variability, limitations of the assessment methods or a combination of all three., (© 2016 Mac Keith Press.)

Background: Ataxia telangiectasia (AT) is a genetic multisystem disorder, presenting with progressive ataxia, immune deficiency, and propensity toward malignancy. Endocrine abnormalities (growth retardation, reproductive dysfunction, and diabetes) have been described, however detailed information regarding this aspect is lacking. We aimed to characterize endocrine anomalies and growth patterns in a large cohort of AT patients., Methods: Retrospective study comprising all 52 patients (aged 2-26.2 y) followed at a national AT Clinic. Anthropometric and laboratory measurements were extracted from the charts., Results: Median height-SDS was already subnormal during infancy, remaining negative throughout follow up to adulthood. Height-SDS was more impaired than weight-SDS up to age 4 y, thereafter weight-SDS steadily decreased, resulting in progressively lower BMI-SDS. IGF-I-SDS was low (-1.53 ± 1.54), but did not correlate with height-SDS. Gonadal failure was present in all 13 females older than 10 y but only in one male. Two patients had diabetes and 10 had dyslipidemia. Vitamin D deficiency was observed in 52.2% of the evaluated patients., Conclusion: Our results suggest a primary growth abnormality in AT, rather than secondary to nutritional impairment or disease severity. Sex hormone replacement should be considered for female patients. Vitamin D levels should be followed and supplementation given if needed.

Objective: To evaluate the potential link between systemic inflammation and impaired lung function in people with ataxia-telangiectasia (A-T), we hypothesized that serum levels of interleukin (IL)-6, a proinflammatory cytokine, would correlate inversely with lung function in subjects with A-T., Study Design: Consecutive subjects with A-T were recruited from the Johns Hopkins Outpatient A-T Clinical Center. Serum levels of IL-6 and 8 were measured by enzyme-linked immunosorbent assay. Spirometry was performed in subjects ≥ 6 years of age on the same day that serum was obtained for measurements of cytokines., Results: Approximately 80% of subjects had elevated serum IL-6 levels (> 1.0 pg/mL). No association was found between elevated IL-6 and age. Elevated IL-8 levels were found in 23.6% of subjects, and all subjects with elevated IL-8 levels had elevated IL-6 levels. Subjects with elevated IL-6 levels (mean: 6.14 ± 7.47 pg/mL) had significantly lower mean percent forced vital capacity (FVC%, 50.5% ± 17.8%) compared with subjects with normal serum IL-6 levels (FVC% of 66.2 ± 16.1, P = .018). Greater IL-6 levels were associated with lower FVC% even after adjustment for receiving gamma globulin therapy (P = .024) and supplemental nutrition (P = .055)., Conclusions: An association was found between elevated serum IL-6 levels and lower lung function in subjects with A-T. In addition, subjects with both elevated IL-6 and IL-8 had the lowest mean lung function. These findings indicate that markers for systemic inflammation may be useful in identifying individuals with A-T at increased risk for lower lung function and may help in assessing response to therapy., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objective: Ataxia telangiectasia (A-T) is a rare genetic multiorgan disease. Although gastrointestinal involvement is known, hepatic involvement in A-T has not been investigated. We aimed to study the hepatic involvement in a large cohort of patients with A-T., Methods: A retrospective review of patients, studied from January 1986 to January 2015 at a National A-T Center. Clinical data including demographic, genetic, laboratory, nutritional, radiographic, and histological data were retrieved., Results: Fifty-three patients, 27 (49%) boys, age 14.6 ± 5.2 years (range 5.9-26.1 years), were included. Twenty-three patients (43.4%), age 9.9 ± 5.1 years, had consistently abnormal liver enzymes. The mean enzyme levels were alanine aminotransferase 76.8 ± 73.8 IU/L, aspartate aminotransferase 70 ± 50 IU/L, alkaline phosphatase 331 ± 134 IU/L, and gamma glutamyl transferase 114.7 ± 8 IU/L. Evaluation of other etiology of liver disease was negative. Ultrasonography revealed fatty liver in 9 of them (39%). Liver biopsy was performed in 2 patients, revealing mild-to-moderate steatosis in both, and fibrosis in 1 patient. Progression to advanced liver disease occurred in 2 of 23 (9%) patients within 2 to 5 years. Dyslipidemia was significantly associated with abnormal liver enzymes: 3 of 30 (10%) patients without abnormal liver enzymes versus 10 of 23 (45.5%) patients with abnormal liver enzymes, respectively (P < 0.05, Fisher exact test). No correlation was found between hepatic involvement and HbA1C, sex, presence of malignancy, or type of mutation., Conclusions: Abnormal liver enzymes and fatty liver are common in patients with A-T and may progress to advanced liver disease at a young age. These findings are novel and implicate that patients with A-T with abnormal liver enzymes should be evaluated for the presence of liver disease.

Ataxia telangiectasia is an autosomal recessive multisystem disorder characterized by progressive cerebellar ataxia with onset in childhood, oculocutaneous telangiectasia, increased serum alpha-fetoprotein, immunodeficiency, chromosomal instability, and radiation hypersensitivity. Ataxia-telangiectasia mutated gene (ATM) is one of the known genes to be associated with ataxia telangiectasia. We reported the clinical and genetic findings of three early-onset Chinese patients who demonstrated ataxia, oculomotor apraxia, choreoathetosis, myoclonus and telangiectasia of eyes. Sequence analysis of ATM revealed two known nonsense mutations c.8287C>T and c.9139C>T in the siblings. Though the siblings carried the same mutations, they showed different clinical features involving strephenopodia, exotropia, torsion dystonia, myoclonus and extrapyramidal impairments. The other patient was compound heterozygotes for ATM: c.8911C>T and c.7141&#95;7151delAATGGAAAAAT, both of which were not reported previously and not found in 200 control chromosomes. This study widens the spectrum of mutations and phenotypes in ataxia telangiectasia., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Objectives: Ataxia-Telangiectasia (A-T) individuals often present with respiratory muscle weakness, causing recurrent respiratory system infections, asthma-like symptoms, and chronic cough life-threatening events. The cough flow volume maneuver may reveal powerless airflow needed for efficient cough. The study aims to explore cough ability in relation to the flow/volume maneuver., Methods: Data collected retrospectively from clinical charts of 35 A-T patients (age 12.7 ± 4.9 years) included forced expiratory and cough flow/volume maneuvers performed on the same day. Analysis compared among the maneuvers matching indices, numbers of cough-spikes, flow rate decay, and the reference data of similar ages. Adjusted to age, BMI, and number of hospitalizations prior to the tests, values were correlated with the cough indices., Results: Cough peak-flow (C-PF) was propagated within 90 ± 20 ms compared with peak expiratory flow (PEF > 200 ms). C-PF measured values were higher than expiratory peak-flow measured values (3.27 ± 1.53 L/s versus 3.02 ± 1.52 L/s, respectively, but C-PF (%predicted) values were significantly lower than expiratory peak-flow (%predicted) (46 ± 15 versus 68 ± 20 %predicted, respectively, p < 0.002). The number of spikes/maneuver was low when compared with reference (2.0 ± 0.8 versus 6-12 spikes) and cough vital-capacity was lower than expiratory vital capacity (0.95 ± 0.43 versus 1.03 ± 0.47; p < 0.01). Inefficient C-PF was more prevalent in patients suffering from recurrent respiratory illness. The length of wheelchair confinement duration mostly influenced the C-VC level., Conclusions: The cough flow-volume curve can be applied as a method to follow cough ability in patients with A-T who showed a significantly reduced cough capacity. Further studies are needed to establish if the findings may aid decisions regarding cough assistance.

Ataxia telangiectasia (A-T) is a rare, progressive, multisystem disease that has a large number of complex and diverse manifestations which vary with age. Patients with A-T die prematurely with the leading causes of death being respiratory diseases and cancer. Respiratory manifestations include immune dysfunction leading to recurrent upper and lower respiratory infections; aspiration resulting from dysfunctional swallowing due to neurodegenerative deficits; inefficient cough; and interstitial lung disease/pulmonary fibrosis. Malnutrition is a significant comorbidity. The increased radiosensitivity and increased risk of cancer should be borne in mind when requesting radiological investigations. Aggressive proactive monitoring and treatment of these various aspects of lung disease under multidisciplinary expertise in the experience of national multidisciplinary clinics internationally forms the basis of this statement on the management of lung disease in A-T. Neurological management is outwith the scope of this document., (Copyright ©ERS 2015.)

Rationale: Forced vital capacity (FVC) values decrease with progress of the disease in Ataxia telangiectasia (AT)., Objective: To study the effect of this process on airway obstruction determination and life span in AT., Methods: Clinical data and yearly best spirometry maneuvers were collected retrospectively from 37 AT patients (196 spirometry tests) during 5.4 ± 1.8yrs (initial age 4-21 y). Twelve patients were walking (7 of them had recurrent respiratory system infections); 25 subjects were confined to wheelchair, of them 8 patients were towards end-stage lung disease. Spirometry indices included Forced Vital Capacity (FVC), mid-expiratory-flow (FEF25-75), and tidal volume (VT). We calculated FEF25-75/FVC and VT/FVC ratios., Results: FVC declined from 67 ± 8 while walking to 19 ± 6 %predicted values. FEF25-75 values that were elevated (116 ± 23 %predicted) while walking, decreased to 69 ± 27 %predicted at end-stage where 7 patients responded to bronchodilators. VT/FVC ratio was 0.25 ± 0.06 while walking, increased to 0.35 once on wheelchairs, and further increased to 0.57 ± 0.19 at end-stage disease. FEF25-75/FVC ratio was 2.54 ± 0.70 above normal (∼1.0) increasing to 4.16 ± 0.75 at end stage. A sharp elevation was seen in FEF25-75/FVC ratio when FEV1 was still ∼45 %predicted and 2-years prior to death., Conclusions: Having a low baseline-FVC (60% predicted) artificially raises FEF25-75 values, so FEF25-75 of "mild obstruction" values may indicate severe airway obstruction in AT subjects. VT/FVC and FEF25-75/FVC ratios may therefore assist in revealing higher than normal breathing effort. The results further suggest adding VT/FVC and FEF25-75/FVC ratios to pulmonary function assessments in patients with AT., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Background and Aims: Evaluate the nutritional status, plasma concentration of vitamin E and markers of cardiovascular risk in ataxia telangiectasia (AT) patients., Methods: Cross-sectional study with 13 patients with AT and 22 healthy controls, evaluating the following factors: nutritional status, food intake, lipid profile, plasma concentration of vitamin E, malondialdehyde and high sensitivity C-reactive protein, linking them with atherosclerosis risk in AT patients., Results: Average age was 14.6 in the AT group, 30.8% were malnourished and 23.1% had stunting. A greater impairment of lean body mass was found in these patients. Concentrations of triglycerides (TG), total cholesterol (CT), LDL-c, non-HDL cholesterol (NHDL-c) were significantly higher in patients and HDL-c, lower. Vitamin E/total lipids and vitamin E/TG ratios were lower in the AT group, and significant inverse correlation between these ratios and NHDL-c, CT/HDL-c, and LDL-c/HDL-c, log TG/HDL-c was observed in the AT group. Alanine aminotransferase correlated directly and significantly with NHDL-c, CT/HDL-c and LDL-c/HDL-c, in patients., Conclusion: The alterations of lipid metabolism biomarkers suggestive of atherosclerotic risk of male AT patients coupled with lower vitamin E/total lipids ratio and low lean body mass may complicate the clinical course of the disease and emphasizes the importance of multidisciplinary care, routine monitoring of cardiovascular biomarkers and appropriate nutritional guidance., (2015 S. Karger AG, Basel.)

Ataxia telangiectasia (AT) is an autosomal recessive multisystem genetic disorder caused by a mutation in the ATM gene encoding for the ATM protein. AT systemic manifestations include cutaneous telangiectasias, radiosensitivity, immune deficiency with recurrent sinopulmonary infections, and a tendency to develop lymphoid malignancies. These complications are explained by the major role played by ATM in DNA repair. AT is also the second most common childhood onset neurodegenerative disorder of the cerebellum, presenting with progressive ataxia and oculomotor apraxia and often accompanied by extrapyramidal movement disorders. Ataxia typically begins around the time children start to walk at about 1 year of age and leads to wheelchair dependence by the second decade of life. Cerebellar atrophy is evident on imaging after 2 years of life and is progressive. Abnormal DNA repair mechanisms do not entirely explain the pathophysiology in nondividing neurons. The nervous system involvement is better explained by the role ATM plays in antioxidative defense, mitochondrial homeostasis, and DNA chromatin packing. A better understanding of the underlying pathophysiologic mechanisms of this devastating disease may enable disease-modifying treatments in the future. Meanwhile, treatment is mainly supportive and does not change the poor prognosis of the disease although it improves the patient's quality of life., (© 2015 Elsevier B.V. All rights reserved.)

Objective: To assess the clinical spectrum of ataxia-telangiectasia (A-T) in adults, with a focus on movement disorders., Methods: A total of 14 consecutive adults with A-T were included at 2 tertiary adult movement disorders centers and compared to 53 typical patients with A-T. Clinical evaluation, neurophysiologic and video-oculographic recording, imaging, laboratory investigations, and ATM analysis were performed., Results: In comparison with typical A-T cases, our patients demonstrated later mean age at onset (6.1 vs 2.5 years, p < 0.0001), later loss of walking ability (p = 0.003), and longer survival (p = 0.0039). The presenting feature was ataxia in 71% and dysarthria and dystonia in 14% each. All patients displayed movement disorders, among which dystonia and subcortical myoclonus were the most common (86%), followed by tremor (43%). Video-oculographic recordings revealed mostly dysmetric saccades and 46% of patients had normal latencies (i.e., no oculomotor apraxia) and velocities. The α-fetoprotein (AFP) level was normal in 7%, chromosomal instability was found in 29% (vs 100% of typical patients, p = 0.0006), and immunoglobulin deficiency was found in 29% (vs 69%, p = 0.057). All patients exhibited 2 ATM mutations, including at least 1 missense mutation in 79% of them (vs 36%, p = 0.0067)., Conclusion: There is great variability of phenotype and severity in A-T, including a wide spectrum of movement disorders. Karyotype and repeated AFP level assessments should be performed in adults with unexplained movement disorders as valuable clues towards the diagnosis. In case of a compatible phenotype, A-T should be considered even if age at onset is late and progression is slow., (© 2014 American Academy of Neurology.)

The human genetic disorder ataxia telangiectasia (A-T) is characterised by neurodegeneration, immunodeficiency, radiosensitivity, cell cycle checkpoint defects, genomic instability and cancer predisposition. Progressive cerebellar ataxia represents the most debilitating aspect of this disorder. At present, there is no therapy available to cure or prevent the progressive symptoms of A-T. While it is possible to alleviate some of the symptoms associated with immunodeficiency and deficient lung function, neither the predisposition to cancer nor the progressive neurodegeneration can be prevented. Significant effort has focused on improving our understanding of various clinical, genetic and immunological aspects of A-T; however, little attention has been directed towards identifying altered brain structure and function using MRI. To date, most imaging studies have reported radiological anomalies in A-T. This review outlines the clinical and biological features of A-T along with known radiological imaging anomalies. In addition, we briefly discuss the advent of high-resolution MRI in conjunction with diffusion-weighted imaging, which enables improved investigation of the microstructural tissue environment, giving insight into the loss in integrity of motor networks due to abnormal neurodevelopmental or progressive neurodegenerative processes. Such imaging approaches have yet to be applied in the study of A-T and could provide important new information regarding the relationship between mutation of the ataxia telangiectasia mutated (ATM) gene and the integrity of motor circuitry.

Loss of ataxia telangiectasia mutated (ATM) kinase, a key factor of the DNA damage response (DDR) pathway, causes the cancer predisposing and neurodegenerative syndrome ataxia-telangiectasia (A-T). To investigate the mechanisms of neurodegeneration, we have reprogrammed fibroblasts from ATM-null A-T patients and normal controls to pluripotency (human-induced pluripotent stem cells), and derived from these neural precursor cells able to terminally differentiate into post-mitotic neurons positive to >90% for β-tubulin III+/microtubule-associated protein 2+. We show that A-T neurons display similar voltage-gated potassium and sodium currents and discharges of action potentials as control neurons, but defective expression of the maturation and synaptic markers SCG10, SYP and PSD95 (postsynaptic density protein 95). A-T neurons exhibited defective repair of DNA double-strand breaks (DSBs) and repressed phosphorylation of ATM substrates (e.g., γH2AX, Smc1-S966, Kap1-S824, Chk2-T68, p53-S15), but normal repair of single-strand breaks, and normal short- and long-patch base excision repair activities. Moreover, A-T neurons were resistant to apoptosis induced by the genotoxic agents camptothecin and trabectedin, but as sensitive as controls to the oxidative agents. Most notably, A-T neurons exhibited abnormal accumulation of topoisomerase 1-DNA covalent complexes (Top1-ccs). These findings reveal that ATM deficiency impairs neuronal maturation, suppresses the response and repair of DNA DSBs, and enhances Top1-cc accumulation. Top1-cc could be a risk factor for neurodegeneration as they may interfere with transcription elongation and promote transcriptional decline.

A number of diseases exhibit neurodegeneration with/without additional symptoms such as immunodeficiency, increased cancer risk, and microcephalus. Ataxia telangiectasia and Nijmegen breakage syndrome, for example, develop as a result of mutations in genes involved in the DNA damage response. However, such diseases can be difficult to diagnose as they are only rarely encountered by physicians. To overcome this challenge, nine patients with symptoms that resemble those of ataxia telangiectasia, including neurodegeneration, hypogammaglobulinemia, telangiectasia, and/or elevated serum α-fetoprotein, were subjected to whole-exome sequencing (WES) to identify the causative mutations. Molecular diagnosis was achieved in two patients: one displayed CD40 ligand (CD40LG) deficiency, while a second showed a homozygous SIL1 mutation, which has been linked to Marinesco-Sjögren syndrome (MSS). Typical features of CD40LG deficiency and MSS are distinct from the symptoms usually seen in ataxia telangiectasia. These dissociations between phenotype and genotype make it difficult to achieve molecular diagnosis of orphan diseases. Whole-exome sequencing analyses will assist in the molecular diagnosis of such cases and allow the identification of genotypes that would not be expected from the phenotype., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Background: Ataxia telangiectasia (AT) is a genetic syndrome caused by a mutation of chromosome 11. The clinical features are cerebellar ataxia, telangiectasia, and progressive loss of muscular coordination, including an inefficient cough secondary to progression of neurological disease., Objective: To evaluate the effects of inspiratory muscle training (IMT) on ventilation, lung volume, dyspnoea, respiratory muscle strength, and quality of life in patients with AT., Methods: A longitudinal study was conducted with 11 AT patients and nine healthy volunteers. Ventilometry, subjective sensation of dyspnoea, maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and quality of life were assessed before and after a 24-week IMT program. The IMT load used was set at 60% of the MIP, and the training was performed for 20 min daily., Results: Patients with AT had lower height and weight and also had lower respiratory muscle strength and lung volume compared with healthy volunteers. Furthermore, patients with AT showed a significant improvement when pre- and post-IMT were compared for ventilatory pattern: Vt (476.5 ± 135 ml vs. 583.3 ± 66 ml, P = 0.015) and f (23.3 ± 6 rpm vs. 20.4 ± 4 rpm, P = 0.018), and VC (1,664 ± 463 ml/kg vs. 2,145 ± 750 ml/kg, P = 0.002). IMT also significantly improved the sensation of dyspnoea (median 0.5; minimum 0; maximum 1.0; P = 0.022) and respiratory muscle strength: MIP (-22.2 ± 2 cmH2O vs. -38 ± 9 cmH2O, P < 0.001) and MEP (29 ± 7 cmH2O vs. 40 ± 8 cmH2O, P = 0.001). The health and vitality domains of the SF-36 also showed significant improvement (P = 0.009 and P = 0.014, respectively) post-IMT., Conclusion: IMT was effective in improving ventilatory pattern, lung volume, respiratory muscle strength, and the health and vitality domains for quality of life in patients with AT. IMT may be an effective adjunct therapy to drug treatment for patients with AT., (© 2013 Wiley Periodicals, Inc.)

Background: Pulmonary disease contributes to significant morbidity and mortality in people with ataxia telangiectasia (A-T). To determine the association between age and lung function in children and young adults with A-T and to identify factors associated with decreased lung function, pulmonary function tests were performed in 100 consecutive people with A-T., Methods: Children and adults ranging from 6 to 29 years of age and with the diagnosis of A-T were recruited, and underwent pulmonary function tests., Results: The mean forced vital capacity % predicted (FVC %) in the population was 56.6 ± 20.0. Males and females between 6 and 10 years of age had similar pulmonary function. Older females were found to have significantly lower FVCs % than both older males (P < 0.02) and younger females (P < 0.001). The use of supplemental gamma globulin was associated with significantly lower FVC %. A modest correlation was found between higher radiation-induced chromosomal breakage and lower FVC % in males. No significant change in FVC % was found in a subset of subjects (n = 25) who underwent pulmonary function testing on two or more occasions over an average of 2 years., Conclusion: In children and young adults with A-T, older females and people who required supplemental gamma globulin had significantly lower lung function by cross-sectional analysis. Stable lung function is possible over a 2-year period. Recognition of groups who are at higher risk for lower pulmonary function may help direct care and improve clinical outcomes in people with A-T., (© 2013 Wiley Periodicals, Inc.)

DNA double-strand breaks (DSBs) can lead to instability of the genome if not repaired correctly. The MRE11/RAD50/NBS1 (MRN) complex binds DSBs and initiates damage-induced signaling cascades via activation of the ataxia-telangiectasia mutated (ATM) and ataxia-telangiectasia- and rad3-related (ATR) kinases. Mutations throughout MRE11 cause ataxia-telangiectasia-like disorder (ATLD) featuring cerebellar degeneration, and cancer-predisposition in certain kindreds. Here, we have examined the impact on DNA damage signaling of several disease-associated MRE11A alleles to gain greater understanding of the mechanisms underlying the diverse disease sequelae of ATLD. To this end, we have designed a system whereby endogenous wild-type Mre11a is conditionally deleted and disease-associated MRE11 mutants are stably expressed at physiologic levels. We find that mutations in the highly conserved N-terminal domain impact ATM signaling by perturbing both MRE11 interaction with NBS1 and MRE11 homodimerization. In contrast, an inherited allele in the MRE11 C-terminus maintains MRN interactions and ATM/ATR kinase activation. These findings reveal that ATLD patients have reduced ATM activation resulting from at least two distinct mechanisms: (i) N-terminal mutations destabilize MRN interactions, and (ii) mutation of the extreme C-terminus maintains interactions but leads to low levels of the complex. The N-terminal mutations were found in ATLD patients with childhood cancer; thus, our studies suggest a clinically relevant dichotomy in MRE11A alleles. More broadly, these studies underscore the importance of understanding specific effects of hypomorphic disease-associated mutations to achieve accurate prognosis and appropriate long-term medical surveillance.

Purpose: A sensitive imaging technique that assesses ataxia telangiectasia (AT) lung disease without ionizing radiation is highly desirable. We designed a study to evaluate lung changes using magnetic resonance imaging (MRI), and to investigate the relationships among severity and extent of pulmonary abnormalities and clinical, microbiological and functional data in children and young adults with AT., Methods: Fifteen AT patients (age, 11.3 years; range, 6-31) underwent 3.0-T MRI, spirometry, and deep throat or sputum culture. Images were scored using a modified Helbich score., Results: Although only 8 patients (53 %) had recurrent/chronic respiratory symptoms, MRI identified lung abnormalities in all. Bronchiectasis, peribronchial thickening, mucous plugging, and collapse/consolidation were present in 60 %, 87 %, 67 %, and 13 % of cases, respectively, with no difference between subjects with or without respiratory symptoms. No difference in changes of specific scores was found between the two groups, but the total MRI score was higher in patients with respiratory symptoms (6.5 versus 5, respectively; p = 0.02). Total or specific MRI scores were not associated with patients' age. Of all scores, only mucous plugging subscore appeared significantly related to FEV1 (r = 0.7, p = 0.04) and FEF25-75% (r = 0.9, p = 0.001). MRI scores from patients with positive (n = 5) or negative (n = 10) sputum culture were not significantly different., Conclusions: MRI is valuable in the assessment of extent and severity of pulmonary changes in children and adults with AT. It represents an helpful tool for the longitudinal evaluation of patients and may be also used as an outcome surrogate to track the effects of medications.

Ataxia-telangiectasia is known for cerebellar degeneration, but clinical descriptions of abnormal tone, posture, and movements suggest involvement of the network between cerebellum and basal ganglia. We quantitatively assessed the nature of upper-limb movement disorders in ataxia-telangiectasia. We used a three-axis accelerometer to assess the natural history and severity of abnormal upper-limb movements in 80 ataxia-telangiectasia and 19 healthy subjects. Recordings were made during goal-directed movements of upper limb (kinetic task), while arms were outstretched (postural task), and at rest. Almost all ataxia-telangiectasia subjects (79/80) had abnormal involuntary movements, such as rhythmic oscillations (tremor), slow drifts (dystonia or athetosis), and isolated rapid movements (dystonic jerks or myoclonus). All patients with involuntary movements had both kinetic and postural tremor, while 48 (61%) also had resting tremor. The tremor was present in transient episodes lasting several seconds during two-minute recording sessions of all three conditions. Percent time during which episodic tremor was present was greater for postural and kinetic tasks compared to rest. Resting tremor had higher frequency but smaller amplitude than postural and kinetic tremor. Rapid non-rhythmic movements were minimal during rest, but were triggered during sustained arm postures and goal directed arm movements suggesting they are best considered a form of dystonic jerks or action myoclonus. Advancing age did not correlate with the severity of involuntary limb movements. Abnormal upper-limb movements in ataxia-telangiectasia feature classic cerebellar impairment, but also suggest involvement of the network between the cerebellum and basal ganglia.

The autosomal recessive disorder ataxia-telangiectasia (A-T) is characterized by genome instability, cancer predisposition and neurodegeneration. Although the role of ataxia-telangiectasia mutated (ATM) protein, the protein defective in this syndrome, is well described in the response to DNA damage, its role in protecting the nervous system is less clear. We describe the establishment and characterization of patient-specific stem cells that have the potential to address this shortcoming. Olfactory neurosphere (ONS)-derived cells were generated from A-T patients, which expressed stem cell markers and exhibited A-T molecular and cellular characteristics that included hypersensitivity to radiation, defective radiation-induced signaling and cell cycle checkpoint defects. Introduction of full-length ATM cDNA into these cells corrected defects in the A-T cellular phenotype. Gene expression profiling and pathway analysis revealed defects in multiple cell signaling pathways associated with ATM function, with cell cycle, cell death and DNA damage response pathways being the most significantly dysregulated. A-T ONS cells were also capable of differentiating into neural progenitors, but they were defective in neurite formation, number of neurites and length of these neurites. Thus, ONS cells are a patient-derived neural stem cell model that recapitulate the phenotype of A-T, do not require genetic reprogramming, have the capacity to differentiate into neurons and have potential to delineate the neurological defect in these patients.

Ataxia telangiectasia (A-T) is a rare autosomal recessive disorder characterized by progressive neurological dysfunction. To date, only supportive care aimed to halt the progressive neurodegeneration is available for the treatment. Recently, an improvement of neurological signs during short-term treatment with betamethasone has been reported. To date, the molecular and biochemical mechanisms by which the steroid produces such effects have not yet been elucidated. Therefore, a review of the literature was carried out to define the potential molecular and functional targets of the steroid effects in A-T. Glucocorticoids (GCs) are capable of diffusing into the CNS by crossing the blood-brain barrier (BBB) where they exert effects on the suppression of inflammation or as antioxidant. GCs have been shown to protect post-mitotic neurons from apoptosis. Eventually, GCs may also modulate synaptic plasticity. A better understanding of the mechanisms of action of GCs in the brain is needed, because in A-T during the initial phase of cell loss the neurological impairment may be rescued by interfering in the biochemical pathways. This would open a new window of intervention in this so far incurable disease., (© 2012 The Author(s) European Journal of Neurology © 2012 EFNS.)

No controlled studies exist regarding the pharmaceutical reduction of ataxia symptoms in ataxia telangiectasia (A-T). In a multicenter, double-blind, randomized, placebo-controlled crossover trial, oral betamethasone (BETA) and placebo were compared in terms of their reduction of ataxia symptoms as assessed with the International Cooperative Ataxia Rating Scale (ICARS). In this study of 13 A-T children, betamethasone reduced the ICARS total score by a median of 13 points in the intent-to-treat population and 16 points in the per-protocol population (ie, median percent decreases of ataxia symptoms of 28% and 31%, respectively). In conclusion, Oral betamethasone could be a promising therapy to relieve ataxia symptoms in A-T patients; however, long-term effectiveness and safety must be established. (Current Controlled Trials, number ISRCTN08774933.), (Copyright © 2012 Movement Disorder Society.)