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Background: (1) Description of clinical and cranial MRI features in the original Pontine Autosomal Dominant Microangiopathy with Leukoencephalopathy (PADMAL) family and correlation with the segregation analysis of the causative collagen 4A1 gene (COL4A1) variant. (2) Sequence analysis of the COL4A1 miRNA-binding site containing the causative variant in two independent cross-sectional samples of sporadic stroke patients. Patients and methods: Sanger sequencing of the COL4A1 miRNA-binding site in the PADMAL family and 874 sporadic stroke patients. Results: PADMAL shows adult-onset usually between 30 and 50 years of age with initial brainstem-related symptoms most commonly dysarthria, with progression to dementia and tetraparesis. Radiologically pontine lacunes are followed by supratentorial white matter involvement. Radiological onset may precede clinical symptoms. We found no variants in the COL4A1 miRNA-binding site of sporadic stroke patients. Conclusion: Our results allow an early diagnosis of PADMAL based on cranial MRI, clinical signs, and confirmatory sequencing of the COL4A1 miRNA-29-binding site. COL4A1 miRNA-29-binding site variants do not contribute to a sizeable proportion of sporadic stroke. [ABSTRACT FROM AUTHOR]

Background: Fabry disease is an inherited metabolic disorder with various symptoms. Neurological manifestations are small fiber neuropathy, cerebral white matter lesions (WML), megadolicho basilar artery, and stroke. The relevance of the D313Y variant in the galactosidase alpha gene is controversially discussed. Objectives: We aimed at elucidating the implications of this differential diagnosis of multiple sclerosis (MS), focussing on the analysis of WML over time and correlations with other markers. Methods: We reviewed retrospectively the clinical, laboratory, and magnetic resonance imaging data of 21 carriers of the D313Y variant at a single German outpatient clinic for MS between 2004 and 2021. Results: In our cohort (15 females, 6 males), mean age at diagnosis was 44.1 ± 16.3 years, and mean follow-up duration was 3.1 ± 3.9 years. WML were rated on both, the Fazekas scale and the age-related white matter changes rating scale, and were of variable interindividual extent. Follow-up imaging showed virtually no progress. WML did not correlate with the severity of clinical findings or lysoGb3 levels. Symptomatic carriers of the variant are characterized by an almost complete lack of internal organ manifestations and laboratory findings, usually associated with Fabry disease. Conclusion: WML in carriers of the D313Y variant do not seem to be suitable for assessing or predicting the (para-) clinical status. Concerning MS patients, the variant and its clinical signs can be a differential diagnosis, but also a co-factor. Imaging and cerebrospinal fluid findings facilitate the distinction between both entities. [ABSTRACT FROM AUTHOR]

GBA variants are associated with increased risk and earlier onset of Parkinson's disease (PD), and more rapid disease progression especially with "severe" variants typified by p.L483P. GBA mutation screening studies from South-East Asia, with > 650 million inhabitants of diverse ancestries, are very limited. We investigated the spectrum of GBA variants, and associated clinico-demographic features, in a multi-ethnic PD cohort in Malaysia. Patients (n = 496) were recruited from seven centres, primarily of Chinese (45%), Malay (37%), and Indian (13%) ethnicities. All GBA coding exons were screened using a next-generation sequencing-based PD gene panel and verified with Sanger sequencing. We identified 14 heterozygous GBA alleles consisting of altogether 17 missense variants (8 classified as pathogenic or likely pathogenic for PD) in 25 (5.0%) patients, with a substantially higher yield among early (< 50 years) vs. late-onset patients across all three ethnicities (9.1–13.2% vs. 1.0–3.2%). The most common variant was p.L483P (including RecNciI, n = 11, 2.2%), detected in all three ethnicities. Three novel variants/recombinant alleles of uncertain significance were found; p.P71L, p.L411P, and p.L15S(;)S16G(;)I20V. The common European risk variants, p.E365K, p.T408M, and p.N409S, were not detected. A severe disease course was noted in the majority of GBA-variant carriers, across a range of detected variants. We report a potentially novel observation of spine posture abnormalities in GBA-variant carriers. This represents the largest study on GBA variation from South-East Asia, and highlights that these populations, especially those with EOPD, would be relevant for studies including clinical trials targeting GBA pathways. [ABSTRACT FROM AUTHOR]

Neurometabolic disorders are often inherited and complex disorders that result from abnormalities of enzymes important for development and function of the nervous system. Recently, biallelic mutations in NAXE (APOA1BP) were found in patients with an infantile, lethal, neurometabolic disease. Here, exome sequencing was performed in two affected sisters and their healthy parents. The best candidate, NAXE, was tested for replication in exome sequencing data from 4351 patients with neurodevelopmental disorders. Quantitative RT-PCR, western blot and form factor analysis were performed to assess NAXE expression, protein levels and to analyze mitochondrial morphology in fibroblasts. Vitamin B3 was administered to one patient. Compound heterozygous missense (c.757G>A: p.Gly253Ser) and splicing (c.665-1G>A) variants in NAXE were identified in both affected sisters. In contrast to the previously reported patients with biallelic NAXE variants, our patients showed a milder phenotype with disease onset in early adulthood with psychosis, cognitive impairment, seizures, cerebellar ataxia and spasticity. The symptoms fluctuated. Additional screening of NAXE identified three novel homozygous missense variants (p.Lys245Gln, p.Asp218Asn, p.Ile214Val) in three patients with overlapping phenotype (fluctuating disease course, respiratory insufficiency, movement disorder). Lastly, patients with the c.665-1G>A splicing variant showed a significant reduction of NAXE expression compared to control fibroblasts and undetectable NAXE protein levels compared to control fibroblasts. Based on the metabolic pathway, vitamin B3 and coenzyme Q treatment was introduced in one patient in addition to antiepileptic treatment. This combination and avoidance of triggers was associated with continuous motor and cognitive improvement. The NAXE variants identified in this study suggest a loss-of-function mechanism leading to an insufficient NAD(P)HX repair system. Importantly, symptoms of patients with NAXE variants may improve with vitamin B3/coenzyme Q administration. [ABSTRACT FROM AUTHOR]

Methylmalonic acidemia (MMA), an inherited metabolic disease, results from genetic defects in methylmalonyl-CoA mutase or any of the proteins involved in adenosylcobalamin synthesis. This enzyme is classified into several complementation groups and genotypic classes. In this work we explain the biochemical, structural and genetic analysis of 25 MMA patients, from Iran. The diagnosis was established by the measurement of propionylcarnitine in blood using tandem mass spectrometry and confirmed using a gas chromatography-flame ionization detector. Using clinical, biochemical, structural and molecular analyses we identified 15 mut MMA, three cblA, one cblB, and four cblC-deficient patients. Among mutations identified in the MUT gene (MUT) only one, the c.1874A>C (p.D625A) variant, is likely a mut− mutation. The remaining mutations are probably mut0. Here, we present the first molecular analysis of MMA in Iranian patients and have identified eight novel mutations. Four novel mutations (p.D625A, p.R326G, p.V157F, p.F379L) were seen exclusively in patients from northern Iran. One novel splice site mutation (c.2125-3C>G) in MUT and two novel mutation (p.N225M and p.A99P) in the MMAA gene were associated with patients from eastern Iran. The rs184829210 SNP was recognized only in patients with the novel c.958G>A (p.A320T) mutation. This study confirms pathogenesis of deficient enzyme activity in MUT, MMAA, MMAB, and MMACHC as previous observations. These results could act as a basis for the performance of pharmacological therapies for increasing the activity of proteins derived from these mutations. [ABSTRACT FROM AUTHOR]

The molecular dysfunction in X-linked dystonia-parkinsonism is not completely understood. Thus far, only noncoding alterations have been found in genetic analyses, located in or nearby the TATA-box binding protein-associated factor 1 ( TAF1) gene. Given that this gene is ubiquitously expressed and is a critical component of the cellular transcription machinery, we sought to study differential gene expression in peripheral models by performing microarray-based expression profiling in blood and fibroblasts, and comparing gene expression in affected individuals vs. ethnically matched controls. Validation was performed via quantitative polymerase chain reaction in discovery and independent replication sets. We observed consistent downregulation of common TAF1 transcripts in samples from affected individuals in gene-level and high-throughput experiments. This signal was accompanied by a downstream effect in the microarray, reflected by the dysregulation of 307 genes in the disease group. Gene Ontology and network analyses revealed enrichment of genes involved in RNA polymerase II-dependent transcription, a pathway relevant to TAF1 function. Thus, the results converge on TAF1 dysfunction in peripheral models of X-linked dystonia-parkinsonism, and provide evidence of altered expression of a canonical gene in this disease. Furthermore, our study illustrates a link between the previously described genetic alterations and TAF1 dysfunction at the transcriptome level. [ABSTRACT FROM AUTHOR]

Mitochondrial diseases, predominantly mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS), may occasionally underlie or coincide with ischemic stroke (IS) in young and middle-aged individuals. We searched for undiagnosed patients with MELAS in a target subpopulation of unselected young IS patients enrolled in the Stroke in Young Fabry Patients study (sifap1). Among the 3291 IS patients aged 18-55 years recruited to the sifap1 study at 47 centers across 14 European countries, we identified potential MELAS patients with the following phenotypic features: (a) diagnosed cardiomyopathy or (b) presence of two of the three following findings: migraine, short stature (≤165 cm for males; ≤155 cm for females), and diabetes. Identified patients' blood samples underwent analysis of the common MELAS mutation, m.3243A>G in the MTTL1 gene of mitochondrial DNA. Clinical and cerebral MRI features of the mutation carriers were reviewed. We analyzed blood samples of 238 patients (177 with cardiomyopathy) leading to identification of four previously unrecognized MELAS main mutation carrier-patients. Their clinical and MRI characteristics were within the expectation for common IS patients except for severe hearing loss in one patient and hyperintensity of the pulvinar thalami on T1-weighted MRI in another one. Genetic testing for the m.3243A>G MELAS mutation in young patients with IS based on phenotypes suggestive of mitochondrial disease identifies previously unrecognized carriers of MELAS main mutation, but does not prove MELAS as the putative cause. [ABSTRACT FROM AUTHOR]

Homozygous or compound heterozygous mutations in the glucocerebrosidase gene cause Gaucher disease. Moreover, heterozygous glucocerebrosidase gene mutations represent the most common genetic risk factor for Parkinson's disease (PD) known so far. Substantia nigra (SN) hyperechogenicity, a sonographic feature thought to reflect iron accumulation, has been described in both PD and Gaucher disease patients. Here we studied how clinical, genetic, and brain sonographic findings relate to the occurrence of PD in Gaucher disease. Sixteen Gaucher disease patients, 12 PD patients, and 32 control subjects were enrolled. The glucocerebrosidase genotypes were identified by DNA sequencing. All subjects underwent transcranial ultrasound, and eight Gaucher disease patients additionally MRI for comparison with SN ultrasound findings. SN hyperechogenicity and reduced echogenicity of brainstem raphe were more frequent in Gaucher disease patients (62, 37 %) than in controls (12, 12 %; p < 0.001, p < 0.05). SN hyperechogenicity in Gaucher disease patients was unrelated to type or severity of glucocerebrosidase gene mutation, but correlated with iron-sensitive MRI-T2 hypointensity of SN pars compacta, and with age at start of enzyme replacement therapy. While none of the five Gaucher disease patients with signs of PD (definite PD, n = 4; early PD, n = 1) had severe glucocerebrosidase gene mutations known to cause neuronopathic Gaucher disease, all carried a N370S allele, previously reported to predict non-neuronopathic Gaucher disease. Hyposmia, higher non-motor symptoms score (constipation, depression, executive dysfunction), and SN hyperechogenicity were characteristic features of Gaucher disease-related PD. We conclude that the combined clinical, genetic, and transcranial sonographic assessment may improve the PD risk evaluation in Gaucher disease. [ABSTRACT FROM AUTHOR]

Molecular characterization is important for an accurate diagnosis in hereditary spastic paraplegia (HSP). Mutations in the gene SPAST (SPG4) are the most common cause of autosomal dominant forms. We performed targeted next generation sequencing (NGS) in a SPAST-negative HSP sample. Forty-four consecutive HSP patients were recruited from an adult neurogenetics clinic in Sydney, Australia. SPAST mutations were confirmed in 17 subjects, and therefore 27 SPAST-negative patients were entered into this study. Patients were screened according to mode of inheritance using a PCR-based library and NGS (Roche Junior 454 sequencing platform). The screening panel included ten autosomal dominant (AD) and nine autosomal recessive (AR) HSP-causing genes. A genetic cause for HSP was identified in 25.9 % (7/27) of patients, including 1/12 classified as AD and 6/15 as AR or sporadic inheritance. Several forms of HSP were identified, including one patient with SPG31, four with SPG7 (with one novel SPG7 mutation) and two with SPG5 (including two novel CYP7B1 frameshift mutations). Additional clinical features were noted, including optic atrophy and ataxia for patients with SPG5 and ataxia and a chronic progressive external ophthalmoplegia-like phenotype for SPG7. This protocol enabled the identification of a genetic cause in approximately 25 % of patients in whom one of the most common genetic forms of HSP (SPG4) was excluded. Targeted NGS may be a useful method to screen for mutations in multiple genes associated with HSP. More studies are warranted to determine the optimal approach to achieve a genetic diagnosis in this condition. [ABSTRACT FROM AUTHOR]

Headache as symptom of stroke is linked to gender, history of migraine, younger age, cerebellar stroke, and low blood pressure. These associations have been controversial, large scale studies are missing. We used the stroke in young fabry patients study to examine the association of demographic, clinical and imaging factors with the occurrence of headache in 4,431 young ischaemic stroke patients (18-55 years; mean: 44.7 years) with an ischemic cerebrovascular event (CVE) (ischemic stroke-IS 75.9 %, TIA 24.1 %). Headache in males occurred more frequently in bilateral localisation (right/left/bilateral: 27.5, 24.6, 39.2 %, p < 0.01), but not in females (40.3, 34.7, 39.6 %). Headache occurrence was more often associated in both genders with IS or TIA in the posterior cerebral territory (male: 33.2 %, p < 0.05; female: 51.0 %, p < 0.01) and vertebrobasilar arteries (male: 44.8 %, p < 0.001; female: 51.2 %, p < 0.001). The larger the size of the most prominent lesion the more likely patients were complaining headache during the IS (≤1 cm vs. >half lobe: 19.5 vs. 28.4 % in male, p < 0.001; 28.9 vs. 39.1 % in female, p < 0.01). Binary logistic regression analyses revealed lower age ( p < 0.001), female sex ( p < 0.001), larger size of the largest lesion ( p < 0.001), and localization in the vertebrobasilar territory ( p < 0.001) as predictors for headache during CVE. Headache at stroke onset is more common during IS in females, younger patients, with greater size of the acute lesion, and affected in posterior cerebral artery or vertebrobasilar system. Headache is a leading symptom in specific combination of stroke factors. These factors should be taken into account when patients report headache during IS or TIA. [ABSTRACT FROM AUTHOR]

In the present study the expression patterns of ADAM (a disintegrin and metalloprotease) genes in the chicken developing lens were analyzed. Using in situ hybridization, we found that seven members of the ADAM family including ADAM9, ADAM10, ADAM12, ADAM13, ADAM17, ADAM22, and ADAM23 are expressed in the developing embryonic lens. From embryonic incubation day (E) 2 to E3, most of the ADAMs investigated here are expressed in the lens placode and lens vesicle. From E5 to E7, all seven ADAMs, but predominantly ADAM9 and ADAM10, are throughly expressed in the central epithelium, as well as in the proliferating lens epithelium and the equatorial lens epithelium. From E9 to E14, expression of ADAM9, ADAM10, and ADAM17 decreases moderately in these regions. ADAM12 and ADAM13 are weakly expressed in the central epithelium and the lens epithelium, and are not detectable from E14 onward. ADAM22 and ADAM23 are expressed in the central epithelium, the lens epithelium and the equatorial lens epithelium at E5 and decrease gradually afterwards in the same regions. At E16, only weak ADAM9, ADAM10 and ADAM17 signals are found in the anterior lens epithelium. The changing spatiotemporal expression of the seven ADAMs suggests a regulatory role for these molecules during chicken lens development. [ABSTRACT FROM AUTHOR]

The orexinergic system interacts with several functional states of emotions, stress, hunger, wakefulness and behavioral arousal through four pathways originating in the lateral hypothalamus (LH). Hundreds of orexinergic efferents have been described by tracing studies and direct immunohistochemistry of orexin in the forebrain, olfactory regions, hippocampus, amygdala, septum, basal ganglia, thalamus, hypothalamus, brain stem and spinal cord. Most of these tracing studies investigated the whole orexinergic projection to all regions of the intracranial part of the CNS. To identify the orexinergic efferents at the subnuclear level of resolution, we focussed on the orexinergic target in the amygdala, which is substantially involved in the LH output and contributes mostly to the functional outcome of the orexinergic system and the basal ganglia. Immunohistochemical identification of axonal orexin A and orexin B in male adult rats has been performed on serial sections. In the extended amygdala many new orexinergic targets were found in the anterior amygdaloid area (dense), anterior cortical nucleus (moderate), amygdalostriatal transition region (moderate), basolateral regions (moderate), basomedial nucleus (moderate), several bed nucleus of the stria terminals regions (few to dense), central amygdaloid subdivisions (dense), posteromedial cortical nucleus (moderate) and medial amygdaloid subnuclei (dense). Furthermore, the entopeduncular nucleus has been newly identified as another target for orexinergic fibers with a high density. These results suggest that subdivisions and subnuclei of the extended amygdala are specific targets of the orexinergic system. [ABSTRACT FROM AUTHOR]

Niemann-Pick type C 1 (NPC1) disease is an autosomal recessive cholesterol transport defect resulting in a neurodegenerative process in patients mainly at an early age, although some patients may start with manifestation in adult. Since loss of myelin is considered as a main pathogenetic factor, the precise mechanism inducing dysmylination in NPC1 disease is still unclear. In the present study, a quantitative evaluation on the myelin protein and its regulatory factors of oligodendrocytes, such as SRY-related HMG-box 10 (Sox10), Yin Yang 1 factor (YY1) and myelin gene regulatory factor (MRF), in different parts of the brain and spinal cord was performed in NPC1-mutant mice. The results showed that NPC1 protein was expressed in oligodendrocytes and the amount of myelin protein was generally decreased in all parts of the brain and spinal cord in NPC1-mutant mice. Compared to wild type, the amount of Sox10 and YY1 was not different in NPC1-mutant mice, but MRF was significantly decreased, suggesting a possible mechanism perturbing differentiation of oligodendrocytes and the myelination process in the NPC1-mutant mouse. [ABSTRACT FROM AUTHOR]

Spinocerebellar ataxia (SCA17) is a rare genetic disorder characterized by a variety of neuropsychiatric symptoms. Recently, using magnetic resonance imaging (MRI) voxel-based morphometry (VBM), several specific functional–structural correlations comprising differential degeneration related to motor and psychiatric symptoms were reported in patients with SCA17. To investigate gray matter volume (GMV) changes over time and its association to clinical neuropsychiatric symptomatology, nine SCA17 mutation carriers and nine matched healthy individuals underwent a detailed neuropsychiatric clinical examination and a high-resolution T1-weighted volume MRI scan, both at baseline and follow-up after 18 months. Follow-up images revealed a progressive GMV reduction in specific degeneration patterns. In contrast to healthy controls, SCA17 patients showed a greater atrophy not only in cerebellar regions but also in cortical structures such as the limbic system (parahippocampus, cingulate) and parietal precuneus. Clinically, progression of motor symptoms was more pronounced than that of psychiatric symptoms. Correlation with the clinical motor scores revealed a progressive reduction of GMV in cerebellar and cerebral motor networks, whereas correlation with psychiatric scores displayed a more widespread GMV impairment in frontal, limbic, parietal, and also cerebellar structures. Interestingly, changes in global functioning were correlated with bilateral atrophy within the para-/hippocampus. While there was a good temporal association between worsening of motor symptoms and progression in cerebral and cortical neurodegeneration, the progression in psychiatric related neurodegeneration seemed to be more widespread and complex, showing progressive atrophy that preceded the further development of clinical psychiatric symptoms. [ABSTRACT FROM AUTHOR]

The variability and mutational changes of the CAG microsatellite in the TATA-box binding protein gene (TBP) were studied. We sequenced the microsatellite of the TBP gene of 25 unrelated individuals from northern Germany (10 SCA17 patients and 15 unaffected control individuals). In addition, the microsatellites were sequenced from individuals of 10 northern German families with at least one family member affected by SCA17. To study also the evolutionary history of this CAG/CAA microsatellite in nonhuman primates, the homologous regions were analysed from Pan troglodytes, Gorilla gorilla, Pongo pygmaeus, P. abellii, Hylobates lar, Nomascus leucogenys, Symphalangus syndactylus, Macaca mulatta, Papio hamadryas, Colobus polykomos and Callithrix jacchus. Three major conclusions were drawn: (i) Patterns of synonymous CAA interruptions in the microsatellite are characteristic and likely to result from selection for stabilizing the repetitive region; (ii) Interspecific comparisons indicate that SCA17 is likely to be a human trait. The most common allele in humans (37 repeats) is close to the threshold value upon which neurodegenerative changes can occur and may act as a repository for expanded, pathogenic alleles; (iii) The cassette-like structure of five out of 17 expanded alleles can be attributed to unequal crossing over. This can explain the rare and sporadic de novo generation of SCA17 alleles.European Journal of Human Genetics (2007) 15, 81–87. doi:10.1038/sj.ejhg.5201721; published online 11 October 2006 [ABSTRACT FROM AUTHOR]

Transplantation of cells derived from embryonic stem cells is currently under investigation as a promising strategy to restore functional deficits in neurodegenerative diseases, e.g. Parkinson’s disease. To generate cells suitable for transplantation, a neuronal progenitor cell line (ST14A) was derived from embryonic day 14 rat striatum by stable retroviral transfection of the temperature-sensitive SV40 large T antigen and genetically modified by transfection with constructs of the neurotrophic factors ciliary neurotrophic factor (CNTF) [CNTF-ST14A] and glial cell line-derived neurotrophic factor (GDNF) [GDNF-ST14A], respectively. In order to investigate the capacity of these cells to regulate neuronal growth and physiological differentiation, e.g. remodeling of axons and synaptogenesis, we analyzed the expression of molecules which control the cell fate during embryonic development. For the first time, we found endogenous Wnt-5a, a regulator molecule that can induce dopaminergic phenotype, by RT-PCR, Western blot and flow cytometry in the neuronal progenitor cell line ST14A and its derivatives CNTF-ST14A and GDNF-ST14A. The protein was transiently upregulated at the differentiation-inducing non-permissive temperature of 39°C and it was also secreted into the culture medium. Our findings are based on in vitro investigation of artificially immortalized cell lines. However, they raise the possibility that neuronal progenitor cells that might be used to treat neurodegenerative diseases express Wnt-5a, thus promoting their potential for dopaminergic differentiation. [ABSTRACT FROM AUTHOR]

Perforated whole-cell patch-clamp recordings obtained with nystatin are frequently used to preserve intracellular integrity. However, the perforated-patch configuration may sometimes undergo a spontaneous change into the conventional whole-cell configuration, especially when lymphocytes are investigated. The electrophysiological criteria – previously described – for establishing the existence of the perforated whole-cell configuration have been shown to be insufficient. Thus, the dye eosin, applied to the pipette solution, was tested as a tool for discriminating between the perforated and the conventional whole-cell configurations on rat T-lymphocytes. The dye never entered the cell from the pipette during the entire measurement in the perforated whole-cell configuration. In contrast, all cells in the conventional whole-cell configuration became red immediately after membrane rupture. Eosin barely changed the currents studied. The results suggest that eosin is a dye of choice for verifying a true perforated-patch configuration. [ABSTRACT FROM AUTHOR]

Copyright of Medizinische Klinik (Urban & Vogel) is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Rationale: Clozapine is a unique antipsychotic drug, outstanding for its lack of extrapyramidal side-effects and its superior efficacy in refractory schizophrenia. However, an unambiguous concentration-response relationship has not yet been established. Objective: We investigated serum concentrations of clozapine, norclozapine and clozapine-N-oxide in psychiatric in- and outpatients to identify particular metabolic patterns in clozapine responders and non-responders and putative threshold levels for clozapine response. Methods: Psychiatric assessments, CYP2D6 genotype, and weekly serum concentrations of clozapine, norclozapine and clozapine-N-oxide were obtained in 34 adult schizophrenic in- and outpatients (18 men, 16 women) during 10 weeks of clozapine treatment with a naturalistic dose design. Results: Responders (n=21) displayed significantly lower serum concentrations of clozapine corrected for dose compared to non-responders (n=13; P<0.05), while none of the other parameters (absolute clozapine concentration, metabolite ratios, gender) were different. Smokers had significantly lower dose-corrected clozapine concentrations. A positive correlation was observed between age and average steady state clozapine concentrations. Conclusions: These findings indicate a possible link between CYP activity and response to clozapine that is not mediated through differences in serum concentrations. No clinically meaningful pattern in serum parameters could be identified that differentiates responders from non-responders. Thus, clozapine TDM seems ineffective for predicting clinical response. Smoking behavior is a major determinant of clozapine clearance while CYP2D6 genotype does not impact clozapine disposition. [ABSTRACT FROM AUTHOR]

Copyright of Medizinische Klinik (Urban & Vogel) is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Conclusion: Preparation of DNA from pancreatic juice for subsequent polymerase chain reaction (PCR) is difficult, but manageable. The protocol presented offers a simple and fast solution. This method might be applicable to other complicated samples, such as saliva, wound secretions, or stool washings. Background: Of all the biological samples used for PCR amplification, pancreatic juice is the most problematic because of the presence of potential inhibitory substances and the amount of nucleases. This demands a DNA preparation procedure that is suitable for routine diagnostic PCR, and is therefore efficient and safe. This is particularly true for pancreatic juice obtained during routine endoscopy. Methods: We describe here a simple method utilizing modified phenol/chloroform extraction and precipitation directly from native pancreatic juice suitable for diagnostic PCR applications, such as oncogenes. Results: DNA could be prepared in quantitative amounts from routine endoscopic specimens. DNA could also be prepared from samples kept several days at room temperature. [ABSTRACT FROM AUTHOR]

In the hope of finding a treatable condition, the need for rapid diagnosis in HIV-seropositive patients with brain lesions is apparent. In order to evaluate the efficacy of stereotactic brain biopsy in AIDS patients, we retrospectively studied 25 HIV-infected patients undergoing stereotactic biopsy. Brain lesions were identified with gadolinium-enhanced MRI and/or contrastCT. Brain biopsy was performed using the system of Riechert. From 8 up to 15 small tissue samples from one or two targets were obtained in every patient. The biopsy material was examined cytologically, histologically (including electron microscopy), immunohistochemically and, in part, by animal test and polymerase chain reaction (PCR). A definite diagnosis was achieved in 92%. Diagnosis included primary central nervous system lymphoma (PCNSL) (10), toxoplasmosis (10), progressive multifocal leukoencephalopathy (2) and one case of co-existing toxoplasmosis and cytomegalovirus infection. Two biopsies were non-diagnostic. All PCNSLs showed polymorphic B-cell populations of high malignancy; accurate classification according to the Kiel classification was not possible. In 3 lymphomas Epstein-Barr nuclear antigen (EBNA) 2-mRNA could be detected by PCR and confirmed immunohistochemically by EBNA 2 expression. In 6 cases autopsy confirmed the biopsy diagnosis. Conventional histology was not sufficiently decisive for toxoplasmosis and progressive multifocal leukoencephalopathy, so that immunohistochemistry and animal tests became very important for a final diagnosis. With the help of different morphological and molecular biological techniques stereotactic brain biopsy appears to be an effective method in the diagnosis of HIV-associated brain lesions. In view of the marked radio- and chemosensitivity of PCNSLs it is mandatory to establish an early and accurate histological diagnosis for adequate treatment. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Ataxia Oculomotor Apraxia Type 2: Course Over 27 Years and a Novel Stop Mutation in the Senataxin Gene," by Tobias Haack and colleagues published in a previous issue.

Background: Rare denovo variants represent a significant cause of neurodevelopmental delay and intellectual disability (ID). Methods: Exome sequencing was performed on 4351 patients with global developmental delay, seizures, microcephaly, macrocephaly, motor delay, delayed speech and language development, or ID according to Human Phenotype Ontology (HPO) terms. All patients had previously undergone whole exome sequencing as part of diagnostic genetic testing with a focus on variants in genes implicated in neurodevelopmental disorders up to January 2017. This resulted in a genetic diagnosis in 1336 of the patients. In this study, we specifically searched for variants in 14 recently implicated novel neurodevelopmental disorder (NDD) genes. Results: We identified 65 rare, protein-changing variants in 11 of these 14 novel candidate genes. Fourteen variants in CDK13, CHD4, KCNQ3, KMT5B, TCF20, and ZBTB18 were scored pathogenic or likely pathogenic. Of note, two of these patients had a previously identified cause of their disease, and thus, multiple molecular diagnoses were made including pathogenic/likely pathogenic variants in FOXG1 and CDK13 or in TMEM237 and KMT5B. Conclusions: Looking for pathogenic variants in newly identified NDD genes enabled us to provide a molecular diagnosis to 14 patients and their close relatives and caregivers. This underlines the relevance of re-evaluation of existing exome data on a regular basis to improve the diagnostic yield and serve the needs of our patients. [ABSTRACT FROM AUTHOR]

AMPA-type glutamate receptors (AMPARs), key elements in excitatory neurotransmission in the brain, are macromolecular complexes whose properties and cellular functions are determined by the co-assembled constituents of their proteome. Here we identify AMPAR complexes that transiently form in the endoplasmic reticulum (ER) and lack the core-subunits typical for AMPARs in the plasma membrane. Central components of these ER AMPARs are the proteome constituents FRRS1l (C9orf4) and CPT1c that specifically and cooperatively bind to the pore-forming GluA1-4 proteins of AMPARs. Bi-allelic mutations in the human FRRS1L gene are shown to cause severe intellectual disability with cognitive impairment, speech delay and epileptic activity. Virus-directed deletion or overexpression of FRRS1l strongly impact synaptic transmission in adult rat brain by decreasing or increasing the number of AMPARs in synapses and extra-synaptic sites. Our results provide insight into the early biogenesis of AMPARs and demonstrate its pronounced impact on synaptic transmission and brain function. [ABSTRACT FROM AUTHOR]

A correction to the article "Repeat expansion in spinocerebellar ataxia type 17 alleles of the TATA-box binding protein gene: an evolutionary approach" that was published online on October 11, 2006 is presented.