Search results for "Microcephaly"

Autosomal recessive micrencephaly with simplified gyral pattern, abnormal myelination and arthrogryposis.

1999

The clinical courses, neuroimaging and muscle biopsy findings of two infants born to an inbred Arab family are described. They had a syndrome of micrencephaly with simplified gyral pattern, abnormal myelin formation and arthrogryposis. Increased variation of fiber size was seen in the muscle biopsy, creatine kinase, however was normal. Large areas of muscle were replaced by adipofibrous tissue. The infants had dysmorphic features consistent with the fetal akinesia/hypokinesia sequence. The abnormalities were suggestive of microlissencephaly probably associated with a dysgenetic process in the muscles. The syndrome showed an autosomal recessive inheritance.

Genome-wide variant calling in reanalysis of exome sequencing data uncovered a pathogenic TUBB3 variant.

2021

Almost half of all individuals affected by intellectual disability (ID) remain undiagnosed. In the Solve-RD project, exome sequencing (ES) datasets from unresolved individuals with (syndromic) ID (n = 1,472 probands) are systematically reanalyzed, starting from raw sequencing files, followed by genome-wide variant calling and new data interpretation. This strategy led to the identification of a disease-causing de novo missense variant in TUBB3 in a girl with severe developmental delay, secondary microcephaly, brain imaging abnormalities, high hypermetropia, strabismus and short stature. Interestingly, the TUBB3 variant could only be identified through reanalysis of ES data using a genome-wi…

Microcephaly a clinical-genetic and neurologic approach

2013

A human multisystem disorder with autoinflammation, leukoencephalopathy and hepatopathy is caused by mutations in C2orf69

2021

AbstractBackgroundDeciphering the function of the many genes previously classified as uncharacterized “open reading frame” (orf) completes our understanding of cell function and its pathophysiology.MethodsWhole-exome sequencing, yeast 2-hybrid and transcriptome analyses together with molecular characterization are used here to uncover the function of the C2orf69 gene.ResultsWe identify loss-of-function mutations in the uncharacterized C2orf69 gene in eight individuals with brain abnormalities involving hypomyelination and microcephaly, liver dysfunction and recurrent autoinflammation. C2orf69 contains an N-terminal signal peptide that is required and sufficient for mitochondrial localizatio…

WWOX-related encephalopathies: delineation of the phenotypical spectrum and emerging genotype-phenotype correlation

2014

International audience; BACKGROUND:Homozygous mutations in WWOX were reported in eight individuals of two families with autosomal recessive spinocerebellar ataxia type 12 and in two siblings with infantile epileptic encephalopathy (IEE), including one who deceased prior to DNA sampling.METHODS:By combining array comparative genomic hybridisation, targeted Sanger sequencing and next generation sequencing, we identified five further patients from four families with IEE due to biallelic alterations of WWOX.RESULTS:We identified eight deleterious WWOX alleles consisting in four deletions, a four base-pair frameshifting deletion, one missense and two nonsense mutations. Genotype-phenotype correl…

Age-dependent epileptic encephalopathy associated with an unusual co-occurrence of ZEB2 and SCN1A variants.

2020

Mowat-Wilson syndrome is a genetic disorder associated with a variable phenotype including peculiar facial features associated with intellectual disability, epilepsy, language impairment, and multiple congenital anomalies caused by heterozygous mutation of the ZEB2 gene. The ZEB2 protein is a complex transcription factor that encompasses multiple functional domains that interact with the regulatory regions of target genes including those involved in brain development. Recently, it has been documented that ZEB2 regulates the differentiation of interneuron progenitors migrating from the medial ganglionic eminence to cortical layers by repression of the Nkx2-1 homeobox transcription factor. It…

BCL11A intellectual developmental disorder: defining the clinical spectrum and genotype-phenotype correlations

2021

AbstractPurposeHeterozygous variants in BCL11A underlie an intellectual developmental disorder with persistence of fetal hemoglobin (BCL11A-IDD, a.k.a. Dias-Logan syndrome). We sought to delineate the genotypic and phenotypic spectrum of BCL11A-IDD.MethodsWe performed an in-depth analysis of 42 patients with BCL11A-IDD ascertained through a collaborative network of clinical and research colleagues. We also reviewed 33 additional affected individuals previously reported in the literature or available through public repositories with clinical information.ResultsMolecular and clinical data analysis of 75 patients with BCL11A-IDD identified 60 unique variants (30 frameshift, 7 missense, 6 splic…

Novel Mutations in the Asparagine Synthetase Gene (ASNS) Associated With Microcephaly

2018

Microcephaly is a devastating condition defined by a small head and small brain compared to the age- and sex-matched population. Mutations in a number of different genes causative for microcephaly have been identified, e.g., MCPH1, WDR62, and ASPM. Recently, mutations in the gene encoding the enzyme asparagine synthetase (ASNS) were associated to microcephaly and so far 24 different mutations in ASNS causing microcephaly have been described. In a family with two affected girls, we identified novel compound heterozygous variants in ASNS (c.1165G > C, p.E389Q and c.601delA, p.M201Wfs∗28). The first mutation (E389Q) is a missense mutation resulting in the replacement of a glutamate residue …

LARP7 variants and further delineation of the Alazami syndrome phenotypic spectrum among primordial dwarfisms: 2 sisters.

2019

Abstract Alazami syndrome (AS) (MIM# 615071 ) is an autosomal recessive microcephalic primordial dwarfism (PD) with recognizable facial features and severe intellectual disability due to depletion or loss of function variants in LARP7. To date, 15 patients with AS have been reported. Here we describe two consanguineous Algerian sisters with Alazami PD due to LARP7 homozygous pathogenic variants detected by whole exome sequencing. By comparing these two additional cases with those previously reported, we strengthen the key features of AS: severe growth restriction, severe intellectual disability and some distinguishing facial features such as broad nose, malar hypoplasia, wide mouth, full li…

A girl with an atypical form of ataxia telangiectasia and an additional de novo 3.14Mb microduplication in region 19q12

2011

A 9-year-old girl born to healthy parents showed manifestations suggestive of ataxia telangiectasia (AT), such as short stature, sudden short bouts of horizontal and rotary nystagmus, a weak and dysarthric voice, rolling gait, unstable posture, and atactic movements. She did not show several cardinal features typical of AT such as frequent, severe infections of the respiratory tract. In contrast, she showed symptoms not generally related to AT, including microcephaly, profound motor and mental retardation, small hands and feet, severely and progressively reduced muscle tone with slackly protruding abdomen and undue drooling, excess fat on her upper arms, and severe oligoarthritis. A cranial…