Search results for "Muscular hypotonia"
showing 10 items of 11 documents
NDST1 missense mutations in autosomal recessive intellectual disability.
2014
NDST1 was recently proposed as a candidate gene for autosomal recessive intellectual disability in two families. It encodes a bifunctional GlcNAc N-deacetylase/N-sulfotransferase with important functions in heparan sulfate biosynthesis. In mice, Ndst1 is crucial for embryonic development and homozygous null mutations are perinatally lethal. We now report on two additional unrelated families with homozygous missense NDST1 mutations. All mutations described to date predict the substitution of conserved amino acids in the sulfotransferase domain, and mutation modeling predicts drastic alterations in the local protein conformation. Comparing the four families, we noticed significant overlap in …
Epimutation at human chromosome 14q32.2 in a boy with a upd(14)mat-like clinical phenotype.
2009
Recently, three reports described deletions and epimutations affecting the imprinted region at chromosome 14q32.2 in individuals with a phenotype typical for maternal uniparental disomy of chromosome 14 [upd(14)mat]. In this study, we describe another patient with upd(14)mat-like phenotype including low birth weight, neonatal feeding problems, muscular hypotonia, motor and developmental delay, small hands and feet, and truncal obesity. Conventional cytogenetic analyses, fluorescence in situ hybridization subtelomere screening, multiplex ligation-dependent probe amplification analysis of common microdeletion and microduplication syndromes, and methylation analysis of SNRPN all gave normal re…
Identification of a novel compound heterozygote SCO2 mutation in cytochrome c oxidase deficient fatal infantile cardioencephalomyopathy
2006
UNLABELLED Fatal infantile cardioencephalomyopathy (OMIM No. 604377) is a disorder of the mitochondrial respiratory chain and is characterised by neonatal progressive muscular hypotonia and cardiomyopathy because of severe Cytochrome c oxidase deficiency. Here we report a novel mutation in the Cytochrome c oxidase assembly gene SCO2 in an infant with fatal infantile cardioencephalomyopathy despite normal initial metabolic screening. CONCLUSION In newborns with unexplained muscular hypotonia and cardiomyopathy genetic testing of mitochondrial respiratory chain disorders might be helpful to establish a final diagnosis and guide treatment decisions.
Bainbridge-Ropers syndrome caused by loss-of-function variants in ASXL3: a recognizable condition
2016
International audience; Truncating ASXL3 mutations were first identified in 2013 by Bainbridge et al. as a cause of syndromic intellectual disability in four children with similar phenotypes using whole-exome sequencing. The clinical features - postulated by Bainbridge et al. to be overlapping with Bohring-Opitz syndrome - were developmental delay, severe feeding difficulties, failure to thrive and neurological abnormalities. This condition was included in OMIM as 'Bainbridge-Ropers syndrome' (BRPS, #615485). To date, a total of nine individuals with BRPS have been published in the literature in four reports (Bainbridge et al., Dinwiddie et al, Srivastava et al. and Hori et al.). In this re…
Redefining the MED13L syndrome
2015
Congenital cardiac and neurodevelopmental deficits have been recently linked to the mediator complex subunit 13-like protein MED13L, a subunit of the CDK8-associated mediator complex that functions in transcriptional regulation through DNA-binding transcription factors and RNA polymerase II. Heterozygous MED13L variants cause transposition of the great arteries and intellectual disability (ID). Here, we report eight patients with predominantly novel MED13L variants who lack such complex congenital heart malformations. Rather, they depict a syndromic form of ID characterized by facial dysmorphism, ID, speech impairment, motor developmental delay with muscular hypotonia and behavioral difficu…
Muscular alteration in agyria with pyramidal tract anomaly
1986
A 4-year-old boy with a history of muscular hypotonia, mental retardation, microcephaly, and generalized convulsions was found at autopsy to have agyria, agenesis of the anterior commissure and posterior corpus callosum as well as an abnormal decussation of pyramidal tracts which descended in the spinal dorsal columns. Postmortem muscular alterations included type IIc fiber hypertrophy and type I fiber grouping, variably expressed in individual muscles and intramuscular fascicles. This may represent a developmental delay compatible with a gestational age between the 34th and 40th week. These studies also indicate the importance of examining (a) multiple samples of postmortem muscles and (b)…
Elevated serum triiodothyronine and intellectual and motor disability with paroxysmal dyskinesia caused by a monocarboxylate transporter 8 gene mutat…
2008
Monocarboxylate transporter 8 (MCT8 or SLC16A2) is important for the neuronal uptake of triiodothyronine (T3) in its function as a specific and active transporter of thyroid hormones across the cell membrane, thus being essential for human brain development. We report on a German male with Allan-Herndon-Dudley syndrome presenting with severe intellectual and motor disability, paroxysmal dyskinesia combined with truncal muscular hypotonia, and peripheral muscular hypertonia at his current age of 9 years. Additionally, the patient has a lesion in the left putamen region revealed by magnetic resonance imaging and elevated serum T3 levels. The male appeared to have a hemizygous mutation (R271H)…
Skeletal abnormalities of the upper limbs--neonatal diagnosis of 49,XXXXY syndrome.
2012
A case of neonatal diagnosis of 49,XXXXY syndrome is presented. Clinical identification was prompted by a bilateral thickening of the radioulnar joints and X-ray imaging disclosing almost complete radioulnar synostosis. Conventional karyotyping was initiated and revealed a karyotype of 49,XXXXY. Previously reported neonatal symptoms such as low birth weight, muscular hypotonia, or genital malformations were absent in this case. Microsatellite analysis showed two different X chromosomes each present in two copies, supporting that the four X chromosomes had arisen from a nondisjunction in maternal meiosis I followed by a second nondisjunction involving both X chromosomes in meiosis II. Multid…
Boy with pseudohypoparathyroidism type 1a caused byGNASgene mutation (deltaN377), Crouzon-like craniosynostosis, and severe trauma-induced bleeding
2009
We report on a 6-month-old boy with craniosynostosis, pseudohypoparathyroidism type 1a (PHP1A), and a GNAS gene mutation. He had synostoses of the coronal, frontal, and sagittal sutures, brachyturricephaly, and hydrocephaly. He also had congenital hypothyroidism, round face, full cheeks, shortness of limbs, mild developmental delay, and muscular hypotonia. Because of progressive hydrocephaly, the synostosis was corrected surgically but circulatory decompensation led to disseminated intravascular coagulation and cerebral infarctions. Our patient died 8 days later. Postmortem molecular studies of GNAS, the gene for guanine nucleotide-binding protein, alpha-stimulating activity polypeptide (ge…
Mitochondrial myopathy with lactic acidosis and deficient activity of muscle succinate cytochrome-c-oxidoreductase
1984
A male infant had severe muscular hypotonia from birth. Recurrent vomiting with dehydration and severe metabolic acidosis complicated the course. Elevated lactate (up to 12.3 mmol/l; n less than 2), pyruvate (0.4 mmol/l; n less than 0.05) and alanine levels were found in serum with an abnormal lactate/pyruvate ratio (greater than 30; n less than 15). In urine the concentrations of lactate, pyruvate, alanine and of several intermediates of the citric acid cycle were increased. In muscle, numerous disseminated "ragged red fibres" were found by light microscopy; muscle fibres were found to contain subsarcolemmal aggregates of mitochondria, lipid droplets and glycogen by electromicroscopical me…