Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026827 (hypotonia)
 5,860 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two new cases of del(2)(q37.1) and one case of partial trp(2)(q37) are studied by FISH with cosmid probes from the COL6A3 and PAX3 genes mapped in 2q37.3 and 2q36, respectively. While the PAX3 gene dosage appeared unaffected, the COL6A3 gene was found to be deleted and triplicated, respectively. This finding could explain features of connective tissue disorders such as joint laxity and hypotonia or joint stiffness and epiphyseal dysplasia, particularly documented by congenital dislocation of the radial head. Karyotype-phenotype correlations with reference to published cases are discussed.
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PMID:Deletion or triplication of the alpha 3 (VI) collagen gene in three patients with 2q37 chromosome aberrations and symptoms of collagen-related disorders. 888 75

Waardenburg syndrome (WS) is a neurocristopathy characterized by pigmentation abnormalities of the skin, hair, and iris, as well as sensorineural hearing loss. Contiguous gene deletions encompassing SOX10 are rare, which limits conclusions about genotype-phenotype correlation regarding patient prognosis and management. This study adds to the existing body of knowledge by characterizing a 2.4 Mb deletion [arr[hg19] 22q12.3-q13.1 (36467502-38878207)x1] encompassing SOX10 and 53 additional RefSeq genes in a 15-year-old female with atypical WS. The patient presented with developmental delay, profound bilateral sensorineural hearing loss, heterochromia iridis, hypotonia, and bilateral finger contractures. Published genomic and phenotypic profiles of patients with SOX10-encompassing deletions point toward several plausible candidate gene that could account for the considerable clinical heterogeneity. These studies suggest the existence of modifiers among the co-deleted, dosage-sensitive genes (e.g., MYH9) and among genes whose effect may depend on the unmasking of recessive mutations (e.g., PLA2G6). Finally, we highlight evidence illustrating extensive interconnectivity of SOX10-hypothesizing that haploinsufficiency of SOX10 may "unmask" subtler effects on expression or epistasis associated with variants in SOX10 targets (e.g., DHH), in its partners (e.g., PAX3, EGR2), and in genes with functional overlap (e.g., SOX8, SOX9).
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PMID:Phenotypic variability in Waardenburg syndrome resulting from a 22q12.3-q13.1 microdeletion involving SOX10. 2471 9

In the present paper we report on a case of oculo-auriculo-vertebral spectrum presenting fluorescence in situ hybridization and comparative genomic hybridization tests negative, hypotonia of some branchiomeric muscles (with velo-pharyngeal insufficiency, dysphagia and nasal voice) and non-branchiomeric muscles (with strabismus and limb hypotrophy). On the basis of the left quadriceps muscle biopsy, showing anisometry and prevalence of type 1 fibers, and on literature data, we underline the relevance of TBX1 gene (regulator of neural crest cells and activator of myogenic factors in branchiomeric muscles development) and of PAX3 gene (present in neural crest, inducing migration of these cells and reported in non-branchiomeric muscles). We conclude that the case of OAVS presented a generalized myopathy and we hypothesize that a cluster of genes strictly neural crest cells related, including TBX1 and PAX3, may be responsible of the branchiomeric and non-branchiomeric myopathy; alternatively, a regulatory mechanism abnormally common to OAVS and velo-cardio-facial syndrome could be present.
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PMID:Oculo-auriculo-vertebral spectrum with myopathy and velopharyngeal insufficiency. A case report with a non-branchiomeric muscle biopsy. 2734 3

PAX binding protein 1 (PAXBP1) is an adaptor protein linking the transcription factor PAX3 and PAX7 to the histone methylation machinery. PAXBP1 is a nuclear protein and its high expression is known in brain cerebellar hemisphere and cerebellum. Moreover, it is also found in abundance in muscle precursor cells that are involved in myogenesis and skeletal muscles formation. Whole genome SNP genotyping and exome sequencing in a family with distinct syndrome of global developmental delay and hypotonia mapped the disease locus to the chromosome 21q22.11 and identified a homozygous missense variant (c.1612C>T) in the PAXBP1 gene, respectively. This variant is predicted to change the highly conserved strongly basic arginine at position 538 in the PAX7 binding domain of PAXBP1 to a neutral cysteine (p.Arg538Cys) residue. Arg538 is highly conserved and the variant is predicted to be deleterious by variety of in silico tools. Furthermore, protein modeling studies showed that in the mutant protein (Cys538), the shorter cysteine is incapable of forming hydrogen bond with the side chain of nearby Asp517 due to its reduced size and lower polarizability. As a consequence, a slight local perturbation of the loop conformation in the PAX7 binding domain of the PAXBP1 protein was observed. Our findings suggest that the pathogenic variant in PAX binding protein underlies distinct syndrome of global developmental delay and myopathic hypotonia. This clinical report should prompt a search for mutations in PAXBP1 in patients presenting with developmental delay and hypotonia. Moreover, these results imply that establishment of PAXBP1 targets and its spatiotemporal interaction will help in understanding of development of cerebellar and will provide basis for developing therapeutic approaches.
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PMID:A homozygous potentially pathogenic variant in the PAXBP1 gene in a large family with global developmental delay and myopathic hypotonia. 2854 22