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Aim: Benign paroxysmal torticollis (BPT), benign paroxysmal vertigo (BPV), and benign tonic upward gaze (BTU) are characterized by transient and recurrent episodes of neurological manifestations. The purpose of this study was to analyse the clinical relationships between these syndromes, associated comorbidities, and genetic bases.Method: In this cross-sectional study, clinical data of patients with BPT, BPV, or BTU were collected with a focus on developmental achievements, learning abilities, and rehabilitation. Neuropsychological assessment and genetic testing were performed.Results: Fifty patients (median age at inclusion 6y) were enrolled. Psychomotor delay, abnormal neurological examination, and low or borderline IQ were found in 19%, 32%, and 26% of the patients respectively. Cognitive dysfunction was present in 27% of the patients. CACNA1A gene mutation was identified in eight families, and KCNA1 and FGF14 mutation in one family respectively. The identification of a CACNA1A mutation was significantly associated with BTU (p=0.03) and with cognitive dysfunction (p=0.01). Patients with BPV were less likely to have cognitive dysfunction.Interpretation: Children with BPT, BPV, or BTU are at high risk of impaired psychomotor and cognitive development. These syndromes should not be regarded as benign and should be considered as part of the spectrum of a neurodevelopmental disorder.What This Paper Adds Ok: Patients with benign paroxysmal torticollis (BPT), benign paroxysmal vertigo (BPV), and benign tonic upward gaze (BTU) have an increased risk of psychomotor delay. These patients also have an increased risk of abnormal neurological examination and cognitive dysfunction. Gene mutations, especially in CACNA1A, were identified in 21% of the families. BPT, BTU, and BPV should not be regarded as benign. BPT, BTU, and BPV should be considered as part of the spectrum of a neurodevelopmental disorder. [ABSTRACT FROM AUTHOR]

Epilepsy is a common finding in chromosomal imbalances, but only a few chromosome abnormalities have a characteristic electro-clinical pattern. Trisomy X is one of the most common sex chromosome abnormalities in females, and is associated with considerable phenotypic variability. This report describes four 47,XXX females with mental deficiency and epilepsy. Although a specific electro-clinical pattern could not be defined, the epileptic phenotypes of these patients share many features; we suggest that the association 47,XXX/epilepsy/mental retardation may not be coincidental. This report also enlarges the clinical spectrum of the 47,XXX phenotype. Moreover, these observations highlight the critical role of chromosome X in epilepsy and mental retardation. [Copyright &y& Elsevier]

Summary: We report three children of the same parents who exhibited various types of cognitive disorders, ranging from severe mental deficiency with transient autistic-like regression to specific neuropsychological disabilities, associated with paroxysmal EEG abnormalities with various patterns of severity. This familial association highly suggests a genetic factor responsible for both epileptic discharges on EEG and cognitive dysfunction. [ABSTRACT FROM AUTHOR]

We report four patients from two families who presented attacks of childhood‐onset episodic ataxia associated with pathogenic mutations in the FGF14 gene. Attacks were triggered by fever, lasted several days, and had variable frequencies. Nystagmus and/or postural tremor and/or learning disabilities were noticed in individuals harboring FGF14 mutation with or without episodic ataxia. These cases and literature data delineate the FGF14‐mutation‐related episodic ataxia phenotype: wide range of age at onset (from childhood to adulthood), variable durations and frequencies, triggering factors including fever, and association to chronic symptoms. We propose to add FGF14‐related episodic ataxia to the list of primary episodic ataxia as Episodic Ataxia type 9. [ABSTRACT FROM AUTHOR]

Objective: Duchenne muscular dystrophy (DMD) is characterised by progressive muscle weakness. It has recently been reported that single nucleotide polymorphisms (SNPs) located in the SPP1 and LTBP4 loci can account for some of the inter-individual variability observed in the clinical disease course. The validation of genetic association in large independent cohorts is a key process for rare diseases in order to qualify prognostic biomarkers and stratify patients in clinical trials.Methods: Duchenne patients from five European neuromuscular centres were included. Information about age at wheelchair dependence and steroid use was gathered. Melting curve analysis of PCR fragments or Sanger sequencing were used to genotype SNP rs28357094 in the SPP1 gene in 336 patients. The genotype of SNPs rs2303729, rs1131620, rs1051303 and rs10880 in the LTBP4 locus was determined in 265 patients by mass spectrometry. For both loci, a multivariate analysis was performed, using genotype/haplotype, steroid use and cohort as covariates.Results: We show that corticosteroid treatment and the IAAM haplotype of the LTBP4 gene are significantly associated with prolonged ambulation in patients with DMD. There was no significant association between the SNP rs28357094 in the SPP1 gene and the age of ambulation loss.Conclusions: This study underlines the importance of replicating genetic association studies for rare diseases in large independent cohorts to identify the most robust associations. We anticipate that genotyping of validated genetic associations will become important for the design and interpretation of clinical trials. [ABSTRACT FROM AUTHOR]

Background: Heterozygous dominant mutations of PRRT2 have been associated with various types of paroxysmal neurological manifestations, including benign familial infantile convulsions and paroxysmal kinesigenic dyskinesia. The phenotype associated with biallelic mutations is not well understood as few cases have been reported. Methods: PRRT2 screening was performed by Sanger sequencing and quantitative multiplex PCR of short fluorescent fragments. A CGH array was used to characterise the size of the deletion at the 16p11.2 locus. Results: Five patients with homozygous or compound heterozygous deleterious PRRT2 gene mutations are described. These patients differ from those with a single mutation by their overall increased severity: (1) the combination of at least three different forms of paroxysmal neurological disorders within the same patient and persistence of paroxysmal attacks; (2) the occurrence of uncommon prolonged episodes of ataxia; and (3) the association of permanent neurological disorders including learning difficulties in four patients and cerebellar atrophy in 2. Conclusions: Our observations expand the phenotype related to PRRT2 insufficiency, and highlight the complexity of the phenotype associated with biallelic mutations, which represents a severe neurological disease with various paroxysmal disorders and frequent developmental disabilities. [ABSTRACT FROM AUTHOR]

We report on the effectiveness of a custom-designed oligonucleotide-based comparative genomic hybridization microarray (array-CGH) to interrogate copy number across the entire 2.2-Mb genomic region of the DMD gene and its applicability in diagnosis. The high-resolution array-CGH, we developed, successfully detected a series of 42 previously characterized large rearrangements of various size, localization and type (simple or complex deletions, duplications, triplications) and known intronic CNVs/Indels. Moreover, the technique succeeded in identifying a small duplication of only 191 bp in one patient previously negative for DMD mutation. Accurate intronic breakpoints localization by the technique enabled subsequent junction fragments identification by sequencing in 86% of cases (all deletion cases and 62.5% of duplication cases). Sequence examination of the junctions supports a role of microhomology-mediated processes in the occurrence of DMD large rearrangements. In addition, the precise knowledge of the sequence context at the breakpoints and analysis of the resulting consequences on maturation of pre-mRNA contribute to elucidating the cause of discrepancies in phenotype/genotype correlations in some patients. Thereby, the array-CGH proved to be a highly efficient and reliable diagnostic tool, and the new data it provides will have many potential implications in both, clinics and research. [ABSTRACT FROM AUTHOR]

Mutation of the gene for α-tocopherol transfer protein causes ataxia with isolated vitamin E deficiency, a disorder usually stabilized or improved after vitamin E supplementation. Dystonia has rarely been described in ataxia with isolated vitamin E deficiency (AVED) patients. We present the case of a young boy with AVED, whose neurological and extra-neurological cardinal symptoms of the disease improved after vitamin E supplementation but who progressively developed generalized dystonia. [Copyright &y& Elsevier]