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Background: Adult patients with adrenoleukodystrophy have a poor prognosis owing to development of adrenomyeloneuropathy. Additionally, a large proportion of patients with adrenomyeloneuropathy develop life-threatening progressive cerebral adrenoleukodystrophy. Leriglitazone is a novel selective peroxisome proliferator-activated receptor gamma agonist that regulates expression of key genes that contribute to neuroinflammatory and neurodegenerative processes implicated in adrenoleukodystrophy disease progression. We aimed to assess the effect of leriglitazone on clinical, imaging, and biochemical markers of disease progression in adults with adrenomyeloneuropathy. Methods: ADVANCE was a 96-week, randomised, double-blind, placebo-controlled, phase 2–3 trial done at ten hospitals in France, Germany, Hungary, Italy, the Netherlands, Spain, the UK, and the USA. Ambulatory men aged 18–65 years with adrenomyeloneuropathy without gadolinium enhancing lesions suggestive of progressive cerebral adrenoleukodystrophy were randomly assigned (2:1 without stratification) to receive daily oral suspensions of leriglitazone (150 mg starting dose; between baseline and week 12, doses were increased or decreased to achieve plasma concentrations of 200 μg·h/mL [SD 20%]) or placebo by means of an interactive response system and a computer-generated sequence. Investigators and patients were masked to group assignment. The primary efficacy endpoint was change from baseline in the Six-Minute Walk Test distance at week 96, analysed in the full-analysis set by means of a mixed model for repeated measures with restricted maximum likelihood and baseline value as a covariate. Adverse events were also assessed in the full-analysis set. This study was registered with ClinicalTrials.gov, NCT03231878; the primary study is complete; patients had the option to continue treatment in an open-label extension, which is ongoing. Findings: Between Dec 8, 2017, and Oct 16, 2018, of 136 patients screened, 116 were randomly assigned; 62 [81%] of 77 patients receiving leriglitazone and 34 [87%] of 39 receiving placebo completed treatment. There was no between-group difference in the primary endpoint (mean [SD] change from baseline leriglitazone: –27·7 [41·4] m; placebo: –30·3 [60·5] m; least-squares mean difference –1·2 m; 95% CI –22·6 to 20·2; p=0·91). The most common treatment emergent adverse events in both the leriglitazone and placebo groups were weight gain (54 [70%] of 77 vs nine [23%] of 39 patients, respectively) and peripheral oedema (49 [64%] of 77 vs seven [18%] of 39). There were no deaths. Serious treatment-emergent adverse events occurred in 14 (18%) of 77 patients receiving leriglitazone and ten (26%) of 39 patients receiving placebo. The most common serious treatment emergent adverse event, clinically progressive cerebral adrenoleukodystrophy, occurred in six [5%] of 116 patients, all of whom were in the placebo group. Interpretation: The primary endpoint was not met, but leriglitazone was generally well tolerated and rates of adverse events were in line with the expected safety profile for this drug class. The finding that cerebral adrenoleukodystrophy, a life-threatening event for patients with adrenomyeloneuropathy, occurred only in patients in the placebo group supports further investigation of whether leriglitazone might slow the progression of cerebral adrenoleukodystrophy. Funding: Minoryx Therapeutics.

PLA2G6 is the causative gene for a group of autosomal recessive neurodegenerative disorders known as PLA2G6-associated neurodegeneration (PLAN). We present a case with early-onset parkinsonism, ataxia, cognitive decline, cerebellar atrophy, and brain iron accumulation. Sequencing of PLA2G6 coding regions identified only a heterozygous nonsense variant, but mRNA analysis revealed the presence of an aberrant transcript isoform due to a novel deep intronic variant (c.2035-274G > A) leading to activation of an intronic pseudo-exon. These results expand the genotypic spectrum of PLAN, showing the paramount importance of detecting possible pathogenic variants in deep intronic regions in undiagnosed patients.

Objective To characterize ocular motor function in patients with Niemann‐Pick disease type C (NPC). Methods In a multicontinental, cross‐sectional study we characterized ocular‐motor function in 72 patients from 12 countries by video‐oculography. Interlinking with disease severity, we also searched for ocular motor biomarkers. Our study protocol comprised reflexive and self‐paced saccades, smooth pursuit, and gaze‐holding in horizontal and vertical planes. Data were compared with those of 158 healthy controls (HC). Results Some 98.2% of patients generated vertical saccades below the 95% CI of the controls’ peak velocity. Only 46.9% of patients had smooth pursuit gain lower than that of 95% CI of HC. The involvement in both downward and upward directions was similar (51°/s (68.9, [32.7–69.3]) downward versus 78.8°/s (65.9, [60.8–96.8]) upward). Horizontal saccadic peak velocity and latency, vertical saccadic duration and amplitude, and horizontal position smooth pursuit correlated best to disease severity. Compensating strategies such as blinks to elicit saccades, and head and upper body movements to overcome the gaze palsy, were observed. Vertical reflexive saccades were more impaired and slower than self‐paced ones. Gaze‐holding was normal. Ocular‐motor performance depended on the age of onset and disease duration. Conclusions This is the largest cohort of NPC patients investigated for ocular‐motor function. Vertical supranuclear saccade palsy is the hallmark of NPC. Vertical upward and downward saccades are equally impaired. Horizontal saccadic peak velocity and latency, vertical saccadic duration and amplitude, and horizontal position smooth pursuit can be used as surrogate parameters for clinical trials. Compensating strategies can contribute to establishing a diagnosis., In this largest cohort of patients with Niemann‐Pick type C disease examined so far, we found that vertical supranuclear saccade (VSSP), and not gaze palsy (VSGP), is the hallmark of this disease. We also identify the surrogate biomarkers that can be used in clinical trials to track the disease progress and treatment effect.

Adrenoleukodystrophy (ALD) encompasses different neurological phenotypes, ranging from the most severe cerebral forms (C-ALD) to the less severe adrenomyeloneuropathy (AMN). As visual system can be varyingly involved, we aimed at exploring whether optical coherence tomography (OCT) may detect retinal abnormalities and their longitudinal changes in adult ALD patients. In this cross-sectional and longitudinal study, we measured the thicknesses of peripapillary retinal nerve fiber layer (pRNFL), macular ganglion cell complex (mGCC), and segmented inner and outer macula at baseline and their changes over time in 11 symptomatic adult ALD males and 10 age- and sex-matched healthy controls. Statistical analyses were performed for the patients as complete group, and splitting them into two subgroups, one (C-ALD) with and the other (AMN) without cerebral parieto-occipital white matter (WM) lesions. In the complete ALD group and in the C-ALD subgroup, the average pRNFL, mGCC, and inner macula were significantly thinner than in controls (p ≤ 0.01), whereas in the AMN subgroup, they were constantly, though non-significantly, thinner. Significant outer macula thinning was also observed (p

ObjectivesTo investigate the relationship between N20-P25 peak-to-peak amplitude (N20p-P25p) of Somatosensory Evoked Potentials (SEPs) and the occurrence of abnormalities of the peripheral and/or central sensory pathways and of myoclonus/epilepsy, in 308 patients with increased SEPs amplitude from upper limbs stimulationMethodsWe compared cortical response (N20p-P25p) in different groups of patients identified by demographic, clinical and neurophysiological factors and performed a cluster analysis for classifying the natural occurrence of subgroups of patients.ResultsNo significant differences of N20p-P25p were found among different age-dependent groups, and in patients with or without PNS/CNS abnormalities of sensory pathways, while myoclonic/epileptic patients showed higher N20p-P25p than other groups. Cluster analysis identified four clusters including patients with myoclonus/epilepsy, patients with central sensory abnormalities, patients with peripheral sensory abnormalities, patients with neither myoclonus nor sensory abnormalities.ConclusionsIncreased N20p-P25p correlated to different pathophysiological conditions: strong cortical hyperexcitability in patients with cortical myoclonus and/or epilepsy and enlarged N20p-P25p, while milder increase of N20p-P25p could be underpinned by plastic cortical changes following abnormalities of sensory pathways, or degenerative process involving the cortex. SEPs increased in amplitude cannot be considered a specific correlated for myoclonus/epilepsy, but it in several neurological disorders may represent a sign of adaptive, plastic and/or degenerative cortical changes.

Pathogenic variants in the ABCD1 gene cause adrenoleukodystrophy (ALD), a progressive metabolic disorder characterized by three core clinical syndromes: a slowly progressive myeloneuropathy, a rapidly progressive inflammatory leukodystrophy (cerebral ALD), and primary adrenal insufficiency. These syndromes are not present in all individuals, and are not related to genotype. Cerebral ALD and adrenal insufficiency require early detection and intervention and warrant clinical surveillance because of variable penetrance and age of onset. Newborn screening has increased the number of presymptomatic individuals under observation, but clinical surveillance protocols vary.We used a consensus-based modified Delphi approach among 28 international ALD experts to develop best-practice recommendations for diagnosis, clinical surveillance, and treatment of ALD patients. We identified 39 discrete areas of consensus. Regular monitoring to detect the onset of adrenal failure and conversion to cerebral ALD is recommended in all male patients. Hematopoeitic cell transplant (HCT) is the treatment of choice for cerebral ALD. This guideline addresses a clinical need in the ALD community worldwide as the number of overall diagnoses as well as presymptomatic individuals is increasing due to newborn screening and greater availability of next generation sequencing. The poor ability to predict the disease course informs current monitoring intervals but remains subject to change as more data emerges. This knowledge gap should direct future research and illustrates once again that international collaboration amongst physicians, researchers and patients is essential to improving care.

Objective: An anaplerotic diet with the odd-chain triglyceride (triheptanoin-C7TG) supplementation was tested as a therapy for Adult Polyglucosan Body Disease (APBD) and is currently being assessed for various metabolic disorders. The aim of this study was to determine any unknown long-term effect of C7TG supplementation on the nutritional status, body composition, resting energy expenditure and biochemical parameters of two siblings with APBD.Methods: Two adult siblings with APBD were treated over a 2-year period with a high fat, low carbohydrate diet, with C7TG oil representing about 30% of the daily caloric intake. We carried out a long-term longitudinal study to determine weight, height, waist circumference; total, intra and extra cellular water by bioimpedance; body fat, lean mass, and bone mineral density by DEXA; resting energy expenditure by indirect calorimeter; glucose and lipid profiles.Results: C7TG supplementation failed to prevent APBD progression, corroborating recent literature. However, long-term C7TG supplementation did not produce any appreciable changes in nutritional status, body composition, resting energy expenditure or biochemical parameters, and no evidence was found of potential adverse effects.Conclusions: Our data suggest that maintenance of C7TG over a 2-year period still leaves a good safety profile in terms of nutritional status, body composition, resting energy expenditure, and biochemical parameters. However further studies involving larger sample sizes, also other diseases, are needed for a deeper understanding of its long-term effects.

Alexander disease (AxD) is a leukodystrophy that primarily affects astrocytes and is caused by dominant variants in the Glial Fibrillary Acidic Protein gene. Three main classifications are currently used, the traditional one defined by the age of onset, and two more recent ones based on both clinical features at onset and brain MRI findings. In this study, we retrospectively included patients with genetically confirmed pediatric-onset AxD. Twenty-one Italian patients were enrolled, and we revised all their clinical and radiological data. Participants were divided according to the current classification systems. We qualitatively analyzed data on neurodevelopment and neurologic decline in order to identify the possible trajectories of the evolution of the disease over time. One patient suffered from a Neonatal presentation and showed a rapidly evolving course which led to death within the second year of life (Type Ia). 16 patients suffered from the Infantile presentation: 5 of them (here defined Type Ib) presented developmental delay and began to deteriorate by the age of 5. A second group (Type Ic) included patients who presented a delay in neuromotor development and started deteriorating after 6 years of age. A third group (Type Id) included patients who presented developmental delay and remained clinically stable beyond adolescence. In 4 patients, the age at last evaluation made it not possible to ascertain whether they belonged to Type Ic or Id, as they were too young to evaluate their neurologic decline. 4 patients suffered from the Juvenile presentation: they had normal neuromotor development with no or only mild cognitive impairment; the subsequent clinical evolution was similar to Type Ic AxD in 2 patients, to Id group in the other 2. In conclusion, our results confirm previously described findings about clinical features at onset; based on follow-up data we might classify patients with Type I AxD into four subgroups (Ia, Ib, Ic, Id). Further studies will be needed to confirm our results and to better highlight the existence of clinical and neuroradiological prognostic factors able to predict disease progression.

A systematic approach to identifying key clinical and neuroimaging findings is paramount for the diagnosis of ultrarare diseases such as adult-onset Krabbe disease.

X-linked adrenoleukodystrophy (ALD) is a metabolic disorder in which very long chain fatty acids (VLCFAs) are accumulated in the nervous system and adrenal cortex, impairing their functions. Three main variants are described in males: adrenomyeloneuropathy (AMN), a cerebral form (cALD or cAMN) and Addison's disease only (AD), while for females no classification is used. To evaluate pain and the functional state of afferent fibers, a series of tests was carried out in male and female patients. Chronic pain occurrence and sensory phenotype profile were assessed in 30 patients (20 male: 10 AMN, 1 cAMN, 1 cALD, 8 AD; and 10 female). A set of instruments assessed the intensity, quality and extent of pain, while a battery of quantitative sensory testing (QST) procedures examined the functional status of Aβ and Aδ fibers. Principal component analysis and hierarchical clustering with sensory responses input were used to identify distinct clusters. Nearly half of the subjects reported pain, with a high prevalence in females and male AMN patients. No sex differences in pain dimensions were found. The sensory responses were heterogeneous, differing among the clinical variants and between genders. Male AMN/cAMN/cALD patients showed the worst impairment. Aβ and Aδ fibers were affected in males and females, but Aβ fibers appeared undamaged in females when tactile sensitivity was tested. Abnormal responses were localized in the lower body district, according to the dying-back pattern of the neuropathy. Cluster analysis showed discrete clusters for each function examined, with well-interpretable sensory and clinical phenotypes. The study of pain and of the sensory profile appears to indicate a difference in the mechanisms underlying the AMN/cAMN/cALD and AD clinical forms and in the treatment of the respective generated pain types.

Niemann-Pick type C (NPC) is a rare lysosomal storage disorder with ocular motor involvement. In a multicontinental, cross-sectional study we characterized ocular motor function in 72 genetically proven patients from twelve countries by means of video-oculography. Interlinking with disease severity, we also searched for ocular motor biomarkers. Our study protocol comprised reflexive and self-paced saccades, smooth pursuit, and gaze-holding in horizontal and vertical planes. Data were compared with those of 158 healthy controls. The Modified Disability Rating Scale, Scale for Assessment and Rating of Ataxia, Spinocerebellar Ataxia Functional Index for neurological status, and Montreal Cognitive Assessment for cognition were also performed.In contrast to previous publications and the common belief that the “downward saccadic system degenerates to greater extent than the upward one”, our measurements of vertical saccades demonstrated that the involvement in both directions was similar. Mean saccadic peak velocity to 20° stimulus was 63.5°/s (SD, 95% CIs of the mean: 59.5, [47.9-79.2]) in NPC patients and 403.1°/s (69.0, [392.0-414.2°/s]) in healthy subjects (pThe number of patient-specific saccadic patterns, incl. slow-pursuit like, hypometric and staircase-pattern saccades suggest varying involvement of the saccadic system with fragmentation of the velocity profile as a sign of omnipause neuron dysfunction. Observed compensating strategies, such as blinks to elicit saccades, head and upper body movements to overcome the gaze palsy, should be used clinically to establish a diagnosis.Vertical reflexive saccades were more impaired and slower than self-paced ones. Ocular motor performance depended on age of onset and disease duration.We found that peak velocity and latency of horizontal saccades, vertical saccadic duration and amplitude, and horizontal position smooth pursuit can be used as surrogate parameters for clinical trials, as they showed the strongest correlation to disease severity. By comparing saccadic with pursuit movements, we showed that 98.2% of patients generated vertical saccades (both up and down) that were below the 95% confidence intervals of the controls’ peak velocity. Only 46.9% of patients had smooth pursuit gain lower than that of 95% of healthy controls. Vertical supranuclear saccade palsy and not vertical supranuclear gaze palsy is the hallmark of NPC disease. The distinction between saccadic and gaze palsy is also important in other neurodegenerative diseases and inborn errors of metabolism with ocular motor involvement, such as progressive supranuclear palsy or Gaucher disease type 3.

Background and purpose: Little is known about hypomyelinating leukodystrophies (HLDs) in adults. The aim of this study was to investigate HLD occurrence, clinical features, and etiology among undefined leukoencephalopathies in adulthood. Methods: We recruited the patients with cerebral hypomyelinating magnetic resonance imaging pattern (mild T2 hyperintensity with normal or near-normal T1 signal) from our cohort of 62 adult index cases with undefined leukoencephalopathies, reviewed their clinical features, and used a leukoencephalopathy-targeted next generation sequencing panel. Results: We identified 25/62 patients (~40%) with hypomyelination. Cardinal manifestations were spastic gait and varying degree of cognitive impairment. Etiology was determined in 44% (definite, 10/25; likely, 1/25). Specifically, we found pathogenic variants in the POLR3A (n=2), POLR1C (n=1), RARS1 (n=1), and TUBB4A (n=1) genes, which are typically associated with severe early-onset HLDs, and in the GJA1 gene (n=1), which is associated with oculodentodigital dysplasia. Duplication of a large chromosome X region encompassing PLP1 and a pathogenic GJC2 variant were found in two patients, both females, with early-onset HLDs persisting into adulthood. Finally, we found likely pathogenic variants in PEX3 (n=1) and PEX13 (n=1) and potentially relevant variants of unknown significance in TBCD (n=1), which are genes associated with severe, early-onset diseases with central hypomyelination/dysmyelination. Conclusions: A hypomyelinating pattern characterizes a relevant number of undefined leukoencephalopathies in adulthood. A comprehensive genetic screening allows definite diagnosis in about half of patients, and demonstrates the involvement of many disease-causing genes, including genes associated with severe early-onset HLDs, and genes causing peroxisome biogenesis disorders.

Mutations in the thyroid hormone transporter MCT8 cause severe intellectual and motor disability and abnormal serum thyroid function tests, a syndrome known as MCT8 deficiency (or: Allan-Herndon-Dudley syndrome, AHDS). Although the majority of patients are unable to sit or walk independently and do not develop any speech, some are able to walk and talk in simple sentences. Here, we report on two cases with such a less severe clinical phenotype and consequent gross delay in diagnosis. Genetic analyses revealed two novel hemizygous mutations in the SLC16A2 gene resulting in a p.Thr239Pro and a p.Leu543Pro substitution in the MCT8 protein. In vitro studies in transiently transfected COS-1 and JEG-3 cells, and ex vivo studies in patient-derived fibroblasts revealed substantial residual uptake capacity of both mutant proteins (Leu543Pro > Thr239Pro), providing an explanation for the less severe clinical phenotype. Both mutations impair MCT8 protein stability and interfere with proper subcellular trafficking. In one of the patients calcifications were observed in the basal ganglia at the age of 29 years; an abnormal neuroradiological feature at this age that has been linked to untreated (congenital) hypothyroidism and neural cretinism. Our studies extend on previous work by identifying two novel pathogenic mutations in SLC16A2 gene resulting in a mild clinical phenotype.

Frontotemporal dementia (FTD) is clinically characterized by behavioral changes, language impairment, and executive dysfunction. FTD usually belongs to the frontotemporal lobar degeneration (FTLD) disease group, and its familial forms are dominantly inherited and linked to a group of genes relevant to frontal and temporal brain pathology, such as MAPT, GRN, C9ORF72, TARDBP, CHMP2B, VCP, and FUS. However, FTD can also be associated with different clinical or pathological phenotypes caused by mutations in other genes, whose heredity can be dominant or recessive. In this work we report on a familial case of FTD characterized by behavioral changes and aphasia, very early onset and very long duration, choreic movements, and white matter lesions at magnetic resonance imaging. We performed a wide-range genetic analysis, using a next generation sequencing approach, to evaluate a number of genes involved in neurodegeneration. We found a previously unreported compound heterozygous mutation in TREM2, that is commonly associated with the recessively inherited Nasu-Hakola disease. We discuss the differential diagnosis to be taken into account in cases of FTD presenting with atypical features.

Metachromatic leukodystrophy (MLD; OMIM #250100) is a panethnic, autosomal recessive disease characterized by intralysosomal accumulation of sulfatides, mainly in oligodendrocytes and Schwann cells. MLD classically presents in childhood, and results from mutations in ARSA gene,1 encoding arylsulfatase A (ARSA), a lysosomal enzyme responsible for sulfatide degradation.

Primary Angiitis of the Central Nervous System (PACNS) is a rare form of idiopathic CNS vasculitis. Neuroimaging is often abnormal and characterized by multifocal brain lesions, but brain biopsy definitely confirms the diagnosis. We report the rare case of a 45-year-old female presenting with symptoms of intracranial hypertension and leukodystrophy-like neuroimaging findings. A comprehensive diagnostic work-up led to the unexpected diagnosis of a definite PACNS which was successfully treated by immunosuppressive treatment. Although rarely, PACNS can present as diffuse leukoencephalopathy on neuroimaging, and mimic even an inherited leukodystrophy. Therefore, in adults with leukodystrophy-like neuroimaging findings, careful examination of clinical and non-clinical features is mandatory to avoid missing the diagnosis of a treatable acquired disease.

Adrenoleukodystrophy (ALD) encompasses different neurological phenotypes, ranging from the most severe cerebral forms (C-ALD) to the less severe adrenomyeloneuropathy (AMN). As visual system can be varyingly involved, we aimed at exploring whether optical coherence tomography (OCT) may detect retinal abnormalities and their longitudinal changes in adult ALD patients.In this cross-sectional and longitudinal study, we measured the thicknesses of peripapillary retinal nerve fiber layer (pRNFL), macular ganglion cell complex (mGCC), and segmented inner and outer macula at baseline and their changes over time in 11 symptomatic adult ALD males and 10 age- and sex-matched healthy controls. Statistical analyses were performed for the patients as complete group, and splitting them into two subgroups, one (C-ALD) with and the other (AMN) without cerebral parieto-occipital white matter (WM) lesions.In the complete ALD group and in the C-ALD subgroup, the average pRNFL, mGCC, and inner macula were significantly thinner than in controls (p ≤ 0.01), whereas in the AMN subgroup, they were constantly, though non-significantly, thinner. Significant outer macula thinning was also observed (p 0.01). In the complete ALD group, follow-up assessment (mean 26.8 months, range 8-48) showed mildly progressive thinning of inferior pRNFL, average mGCC, and inner macula.In adult ALD patients, OCT can reveal retinal abnormalities which are prominent in the more compromised patients, namely those with parieto-occipital WM lesions. The inferior pRNFL, average mGCC and inner macula thicknesses might be sensitive-to-change OCT parameters, but their utility and consistency for short-term longitudinal studies deserve further investigations.

Alexander disease (ALXDRD) is a rare astrocytic leukodystrophy caused by GFAP mutations. The adult-onset (AO) variant is usually characterized by gradual onset of spastic ataxia and bulbar symptoms with slowly progressive course. We report two AO-ALXDRD cases with rapid worsening after minor head trauma. In one of them, the only post-traumatic neuroimaging change was revealed by diffusion tensor imaging study. Our observations support the link between head trauma and ALXDRD progression, and suggest that this progression may be ascribed to microstructural changes. Clinicians should inform ALXDRD patients to minimize the risk of head trauma.

ObjectiveTo identify the phenotypic, neuroimaging, and genotype-phenotype expression of MYORG mutations.MethodsUsing next-generation sequencing, we screened 86 patients with primary familial brain calcification (PFBC) from 60 families with autosomal recessive or absent family history that were negative for mutations in SLC20A2, PDGFRB, PDGBB, and XPR1. In-depth phenotyping and neuroimaging investigations were performed in all cases reported here.ResultsWe identified 12 distinct deleterious MYORG variants in 7 of the 60 families with PFBC. Overall, biallelic MYORG mutations accounted for 11.6% of PFBC families in our cohort. A heterogeneous phenotypic expression was identified within and between families with a median age at onset of 56.4 years, a variable combination of parkinsonism, cerebellar signs, and cognitive decline. Psychiatric disturbances were not a prominent feature. Cognitive assessment showed impaired cognitive function in 62.5% of cases. Parkinsonism associated with vertical nuclear gaze palsy was the initial clinical presentation in 1/3 of cases and was associated with central pontine calcifications. Cerebral cortical atrophy was present in 37% of cases.ConclusionsThis large, multicentric study shows that biallelic MYORG mutations represent a significant proportion of autosomal recessive PFBC. We recommend screening MYORG mutations in all patients with primary brain calcifications and autosomal recessive or negative family history, especially when presenting clinically as atypical parkinsonism and with pontine calcification on brain CT.

Here, we described the first amyotrophic lateral sclerosis patient presenting the c.881 G T p.G294V

Introduction X-linked adrenoleukodystrophy (X-ALD) encompasses several clinical and neuroimaging phenotypes, including cerebral X-ALD, the most common phenotype in children, and adrenomyeloneuropathy, the most common phenotype in adults. A spinocerebellar variant of X-ALD has been described in individuals from the Far East, but the criteria for its diagnosis are unclear. Case report A 35-year-old man from Albania was assessed because of a familial, slowly progressive spastic-ataxic gait associated with neurogenic bladder, sexual dysfunctions, and manic-like behavior. There was no definite clinical feature that suggested cerebellar involvement (eg, cerebellar limb ataxia, nystagmus, and dysarthria). A few months earlier, he had received a diagnosis of Addison disease. Brain magnetic resonance imaging showed a leukoencephalopathy with predominant cerebellum and brainstem involvement, and FDG-PET revealed marked cerebellar hypometabolism. The diagnosis of X-ALD was made because we found an increase of very long chain fatty acids, and a new ABCD1 mutation (c.1627C>T, p.Pro543Ser). Conclusions X-ALD should be included in the differential diagnosis of adult leukoencephalopathies with predominant involvement of infratentorial structures, that is, the cerebellum and brainstem. From a classification perspective, our patient (of white origin), like others (all of Asian origin), should be considered as suffering from a variant of adrenomyeloneuropathy rather than from spinocerebellar X-ALD. Actually, the term "spinocerebellar" or similar ones, such as "cerebello-brainstem dominant form," should be limited to those exceptional cases, in which both the clinical and neuroimaging findings point exclusively (or at least predominantly) to the involvement of infratentorial structures.

Pathogenic variants in polynucleotide kinase 3'-phosphatase (PNKP) gene have been associated with two distinct clinical presentations: autosomal recessive microcephaly, seizures, and developmental delay (MCSZ; MIM 613402) and ataxia with oculomotor apraxia type 4 (AOA4; MIM 616267). More than 40 patients have been reported so far, and their clinical presentations revealed a continuum phenotypic spectrum ranging from congenital microcephaly and early-onset intractable seizures, to adult onset slowly progressive sensory-motor neuropathy and cerebellar ataxia. We describe three unrelated Italian patients with different phenotypes and novel or recurrent pathogenic variants in PNKP gene. Patient 1, homozygous for the recurrent frameshift variant (p.Thr424Glyfs*49), had an early-onset MCSZ phenotype. Late in the disease progression, cerebellar ataxia and peripheral neuropathy were recognized. Patient 2, homozygous for a frameshift variant (p.Ala429Thrfs*42), presented a phenotype partially consistent with MCSZ including microcephaly and developmental delay, but without seizures. Patient 3 is one of the oldest patients described to date and presented polyneuropathy, and cerebellar signs. Biochemical tests showed abnormalities of cholesterol, albumin, or alpha-fetoprotein plasma levels. The clinical presentation of our patients encompassed early-to-adult-onset manifestations. For these cases, the long clinical follow-up allowed an in-depth phenotypic characterization and a better delineation of the natural history of patients carrying PNKP pathogenic variants.

We report the first Italian family affected by hereditary gelsolin amyloidosis (HGA), a rare autosomal dominant disease characterized by adult-onset slowly progressive cranial neuropathy, lattice corneal dystrophy, and cutis laxa. The index case was a 39-year-old male with a 9-year history of progressive bilateral facial nerve palsy. His mother had two episodes of acute facial palsy, and his maternal aunt and grandfather were also affected. Electrophysiological studies confirmed bilateral facial nerve involvement, without signs of peripheral polyneuropathy, and ophthalmological examination showed bilateral lattice corneal dystrophy, in both the index case and his mother. Gelsolin-gene sequencing revealed the heterozygous c.640G>A mutation (p.Asp187Asn) in the proband, his mother and aunt and also in three apparently asymptomatic relatives. The majority of HGA patients come from Finland, although several cases have been reported from other countries. HGA should be considered in the differential diagnosis of progressive or recurrent bilateral facial neuropathy.

Here, we described the first amyotrophic lateral sclerosis patient presenting the c.881 G > T p.G294V TARDBP mutation in homozygous status. The patient belongs to a large pedigree from Morocco. Except for one older affected brother his parents and remaining 8 sibs are referred to be healthy and do not show any neurological sign or symptom. The lack of evidence of TARDBP deletions of any sizes, together with the presence of several AOH segments, strongly suggests that the homozygosity status of p.G294V in the proband derived from parental consanguinity. A revision of the literature and our cohorts indicates that the p.G294V mutation has been detected in only 15 additional ALS patients in heterozygosity and, except for one additional Moroccan patient, all were of Italian origin. The analysis of microsatellite markers surrounding the TARDBP gene in 8 individuals carrying the p.G294V mutation showed that the haplotypic context of the Moroccan proband is shared with most patients of European origin indicating that they carry the p.G294V mutation inherited from a common ancestor. The analysis of the 15 ALS pedigrees (from literature data and present study), strongly suggests a reduced penetrance of the p.G294V mutation since for 13 of the 15 described p.G294V ALS cases the parents did not show any neurological symptoms. This result has potentially important implications in genetic counseling, since genetic testing of a reduced penetrance mutation on pre-symptomatic individuals proves very difficult to predict the outcome based on the genotype.

International audience; In adulthood, spinal cord MRI abnormalities such as T2-weighted hyperintensities and atrophy are commonly associated with a large variety of causes (inflammation, infections, neoplasms, vascular and spondylotic diseases). Occasionally, they can be due to rare metabolic or genetic diseases, in which the spinal cord involvement can be a prominent or even predominant feature, or a secondary one. This review focuses on these rare diseases and associated spinal cord abnormalities, which can provide important but over-ridden clues for the diagnosis. The review was based on a PubMed search (search terms: 'spinal cord' AND 'leukoencephalopathy' OR 'leukodystrophy'; 'spinal cord' AND 'vitamin'), further integrated according to the authors' personal experience and knowledge. The genetic and metabolic diseases of adulthood causing spinal cord signal alterations were identified and classified into four groups: (1) leukodystrophies; (2) deficiency-related metabolic diseases; (3) genetic and acquired toxic/metabolic causes; and (4) mitochondrial diseases. A number of genetic and metabolic diseases of adulthood causing spinal cord atrophy without signal alterations were also identified. Finally, a classification based on spinal MRI findings is presented, as well as indications about the diagnostic work-up and differential diagnosis. Some of these diseases are potentially treatable (especially if promptly recognised), while others are inherited as autosomal dominant trait. Therefore, a timely diagnosis is needed for a timely therapy and genetic counselling. In addition, spinal cord may be the main site of pathology in many of these diseases, suggesting a tempting role for spinal cord abnormalities as surrogate MRI biomarkers.

Background and purpose Adrenomyeloneuropathy (AMN) is the most frequent metabolic hereditary spastic paraplegia. Accordingly, its main site of pathological changes is the spinal cord. It is difficult to quantify AMN progression because commonly used clinical scales have limitations and reliable biomarkers are lacking. The goal was to investigate whether spinal cord and brain quantitative magnetic resonance imaging may assess structural changes in AMN over a relatively short time period. Methods In this longitudinal observational study, the total cord areas (TCAs) from the C2-C3 to T2-T3 level and diffusion tensor imaging (DTI) metrics of the cervical spinal cord and brain portion of the corticospinal tracts in six AMN and six age-matched control subjects at baseline and at a mean follow-up of 22.6 months were assessed. Results A significant reduction of the mean TCA at the T1-T2 level (-3.79%) and a trend of reduction at the lowest cervical levels were observed only in AMN patients. Additionally, DTI metrics revealed significant changes in fractional anisotropy (-8.84%), mean diffusivity (+12.62%) and radial diffusivity (+25.91%) at the C2-C3 level. Discussion The study encourages the assessment of TCAs and spinal cord DTI metrics as surrogate outcome measures in AMN, by focusing on the cervical-thoracic junction and the uppermost part of the cervical spinal cord. Despite the limitation of the results due to the small number of investigated subjects, these observations are useful for forthcoming clinical trials in AMN and possibly other hereditary diseases with predominant spinal cord involvement.

To investigate the cerebral glucose metabolism in subjects with X-linked adrenoleukodystrophy (X-ALD) by using brain [(18)F]-fluorodeoxyglucose PET (FDG-PET).Cross-sectional study in which 12 adults with various forms of X-ALD underwent clinical evaluation and brain MRI, followed by brain FDG-PET, neuropsychological assessment, and personality and psychopathology evaluation using the Symptom Checkist-90-Revised (SCL-90-R) and the Millon Clinical Multiaxial Inventory-III (MCMI-III).When compared to healthy control subjects (n = 27) by using Statistical Parametric Mapping 8 software, the patients with X-ALD-with or without brain MRI changes-showed a pattern of increased glucose metabolism in frontal lobes and reduced glucose metabolism in cerebellum and temporal lobe areas. On single case analysis by Scenium software, we found a similar pattern, with significant (p0.02) correlation between the degree of hypermetabolism in the frontal lobes of each patient and the corresponding X-ALD clinical scores. With respect to personality, we found that patients with X-ALD usually present with an obsessive-compulsive personality disorder on the MCMI-III, with significant (p0.05) correlation between glucose uptake in ventral striatum and severity of score on the obsessive-compulsive subscale.We examined cerebral glucose metabolism using FDG-PET in a cohort of patients with X-ALD and provided definite evidence that in X-ALD the analysis of brain glucose metabolism reveals abnormalities independent from morphologic and signal changes detected by MRI and related to clinical severity. Brain FDG-PET may be a useful neuroimaging technique for the characterization of X-ALD and possibly other leukodystrophies.

Recessive mutations in GJC2, the gene encoding connexin 47 (Cx47), cause Pelizaeus-Merzbacher-like disease type 1 (PMLD1), a severe dysmyelinating disorder. One recessive mutation (p.Ile33Met) has been associated with a much milder phenotype - Hereditary spastic paraplegia type 44 (SPG44). Here we present evidence that a novel Arg98Leu mutation causes an even milder phenotype - a subclinical leukodystrophy. The Arg98Leu mutant forms gap junction plaques in HeLa cells comparable to wild-type Cx47, but electrical coupling was 20-fold lower in cell pairs expressing Arg98Leu than for cell pairs expressing wild-type Cx47. On the other hand, coupling between Cx47Arg98Leu and Cx43WT expressing cells did not show such reductions. Single channel conductance and normalized steady state junctional conductance-junctional voltage (Gj-Vj) relations differed only slightly from those for wild-type Cx47. Our data suggest that that the minimal phenotype in this patient results from a reduced efficiency of opening of Cx47 channels between oligodendrocyte and oligodendrocyte with preserved coupling between oligodendrocyte and astrocyte, and support a partial loss of function model for the mild Cx47 associated disease phenotypes.

X-linked Charcot-Marie-Tooth type 1 (CMTX1) is the second most common type of CMT and is caused by mutations in the Gap-Junction Beta-1 gene (GJB1), encoding connexin 32 which is expressed in Schwann cells as well as in oligodendrocytes. More than 400 GJB1 mutations have been described to date. Many mutation-carrier males have subclinical central nervous system (CNS) involvement, a few show mild CNS clinical signs, whereas only rarely overt though transient CNS dysfunction occurs. We report a 29-year-old man with CMTX1 who, at 16 years, showed short-lived CNS symptoms with transitory white matter abnormalities on cerebral magnetic resonance imaging (MRI) as first clinical presentation of a novel GJB1 mutation (p.Gln99_His100insGln). He had three consecutive episodes of right hemiparesis, together with sensory loss in the paretic limbs and expressive aphasia, all lasting a few hours, over a 2-day period, with concurrent white matter hyperintensity on MRI. These "stroke-like" episodes occurred just after arriving at sea level, after travelling from home at 700 m of altitude. Only a few years later did symptoms of peripheral neuropathy appear. In conclusion, CMTX1 should be included in the differential diagnosis of diseases characterized by transient CNS symptoms and white matter abnormalities on MRI.

Hereditary spastic paraplegias are a heterogeneous group of neurodegenerative disorders, clinically classified in pure and complex forms. Genetically, more than 70 different forms of spastic paraplegias have been characterized. A subgroup of complicate recessive forms has been distinguished for the presence of thin corpus callosum and white matter lesions at brain imaging. This group includes several genetic entities, but most of the cases are caused by mutations in the KIAA1840 (SPG11) and ZFYVE26 genes (SPG15). We studied a cohort of 61 consecutive patients with complicated spastic paraplegias, presenting at least one of the following features: mental retardation, thin corpus callosum and/or white matter lesions. DNA samples were screened for mutations in the SPG11/KIAA1840, SPG15/ZFYVE26, SPG21/ACP33, SPG35/FA2H, SPG48/AP5Z1 and SPG54/DDHD2 genes by direct sequencing. Sequence variants were found in 30 of 61 cases: 16 patients carried SPG11/KIAA1840 gene variants (26.2%), nine patients carried SPG15/ZFYVE26 variants (14.8%), three patients SPG35/FA2H (5%), and two patients carried SPG48/AP5Z1 gene variants (3%). Mean age at onset was similar in patients with SPG11 and with SPG15 (range 11-36), and the phenotype was mostly indistinguishable. Extrapyramidal signs were observed only in patients with SPG15, and epilepsy in three subjects with SPG11. Motor axonal neuropathy was found in 60% of cases with SPG11 and 70% of cases with SPG15. Subjects with SPG35 had intellectual impairment, spastic paraplegia, thin corpus callosum, white matter hyperintensities, and cerebellar atrophy. Two families had a late-onset presentation, and none had signs of brain iron accumulation. The patients with SPG48 were a 5-year-old child, homozygous for a missense SPG48/AP5Z1 variant, and a 51-year-old female, carrying two different nonsense variants. Both patients had intellectual deficits, thin corpus callosum and white matter lesions. None of the cases in our cohort carried mutations in the SPG21/ACP33 and SPG54/DDH2H genes. Our study confirms that the phenotype of patients with SPG11 and with SPG15 is homogeneous, whereas cases with SPG35 and with SPG48 cases present overlapping features, and a broader clinical spectrum. The large group of non-diagnosed subjects (51%) suggests further genetic heterogeneity. The observation of common clinical features in association with defects in different causative genes, suggest a general vulnerability of the corticospinal tract axons to a wide spectrum of cellular alterations.

Microtubule-associated protein tau gene (MAPT) is one of the major genes linked to frontotemporal lobar degeneration, a group of neurodegenerative diseases clinically, pathologically, and genetically heterogeneous. In particular, MAPT mutations give rise to the subgroup of tauopathies. The pathogenetic mechanisms underlying the MAPT mutations so far described are the decreased ability of tau protein to promote microtubule polymerization (missense mutations) or the altered ratio of tau isoforms (splicing mutations), both leading to accumulation of hyperphosphorylated filamentous tau protein. Following a genetic screening of patients affected by frontotemporal lobar degeneration, we identified 2 MAPT mutations, V363I and V363A, leading to atypical clinical phenotypes, such as posterior cortical atrophy. We investigated in vitro features of the recombinant mutated tau isoforms and revealed unusual functional and structural characteristics such as an increased ability to promote microtubule polymerization and a tendency to form oligomeric instead of filamentous aggregates. Thus, we disclosed a greater than expected complexity of abnormal features of mutated tau isoforms. Overall our findings suggest a high probability that these mutations are pathogenic.