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)

Mutations in the inositol 1,4,5-triphosphate receptor type 1 gene (ITPR1) have been identified in families with early-onset spinocerebellar ataxia type 29 (SCA29) and late-onset SCA15, but have not been found in sporadic infantile-onset cerebellar ataxia. We examined if mutations of ITPR1 are also involved in sporadic infantile-onset SCA. Sixty patients with childhood-onset cerebellar atrophy of unknown etiology and their families were examined by whole-exome sequencing. We found de novo heterozygous ITPR1 missense mutations in four unrelated patients with sporadic infantile-onset, nonprogressive cerebellar ataxia. Patients displayed nystagmus, tremor, and hypotonia from very early infancy. Nonprogressive ataxia, motor delay, and mild cognitive deficits were common clinical findings. Brain magnetic resonance imaging revealed slowly progressive cerebellar atrophy. ITPR1 missense mutations cause infantile-onset cerebellar ataxia. ITPR1-related SCA includes sporadic infantile-onset cerebellar ataxia as well as SCA15 and SCA29.
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PMID:Sporadic infantile-onset spinocerebellar ataxia caused by missense mutations of the inositol 1,4,5-triphosphate receptor type 1 gene. 2579 64

The inositol 1,4,5-triphosphate receptor type 1 (ITPR1) gene on chromosome 3 belongs to a family of genes encoding intracellular calcium channel proteins. Such channels are located primarily within the endoplasmic reticular membrane and release Ca2+, an intracellular messenger, which governs numerous intracellular and extracellular functions. We report a family with infantile-onset cerebellar ataxia with delayed motor development and intellectual disability caused by a heterozygous c.805C>T, p.Arg269Trp missense mutation in ITPR1. Both affected family members had postural tremor, hypotonia and dysarthria, but neither had pyramidal signs. Their neuroimaging revealed cerebellar atrophy. Several neurological conditions have been associated with ITPR1 mutations, such as spinocerebellar ataxia type 15 and Gillespie syndrome, and the phenotype may vary according to the location and type of mutations. Spinocerebellar ataxia type 15 is an autosomal dominant disorder, which causes late onset pure cerebellar ataxia. Gillespie syndrome is characterised by bilateral iris hypoplasia, congenital hypotonia, non-progressive ataxia and cerebellar atrophy. In this report, we provide a detailed phenotypic description of a family with a missense mutation in ITPR1. This mutation has only been reported once before. We also provide a literature review of the various phenotypes associated with ITPR1 gene.
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PMID:Missense mutation in the ITPR1 gene presenting with ataxic cerebral palsy: Description of an affected family and literature review. 2882 17

Variants in the inositol 1,4,5-trisphosphate receptor type 1 (ITPR1) gene have been recently identified as a cause of Gillespie's syndrome, a rare inherited condition characterized by bilateral iris hypoplasia, congenital muscle hypotonia, nonprogressive cerebellar ataxia, and intellectual disability. Here, we describe the clinical and genetic findings in a patient who presented with iris hypoplasia, mild gait ataxia, atrophy of the anterior cerebellar vermis but no cognitive deficits. Whole-exome sequencing (WES) uncovered a heterozygous ITPR1 p.Glu2094Lys missense variant, affecting a highly conserved glutamic acid residue for which other amino acid substitutions have already been reported in Gillespie's syndrome patients. Our data expand both the phenotypic and genetic spectrum associated with Gillespie's syndrome and suggest a mutation hotspot on Glu2094.
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PMID:Gillespie's Syndrome with Minor Cerebellar Involvement and No Intellectual Disability Associated with a Novel ITPR1 Mutation: Report of a Case and Literature Review. 3134 Apr 2