Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038379 (strabismus)
 9,317 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Congenital Disorder of Glycosylation (CDG) type Ic is caused by mutations in ALG6. This gene encodes an alpha1,3 glucosyltransferase used for synthesis of the lipid linked oligosaccharide (LLO) precursor of the protein N-glycosylation pathway. CDG-Ic patients have moderate to severe psychomotor retardation, seizures, hypotonia, strabismus, and feeding difficulties. We previously identified a typical patient with a heterozygous point mutation, c.391T>C (p.Tyr131His) in ALG6. Using complementation analysis of ALG6-deficient yeast, we show that this alteration is as severe as the most common disease-causing mutation, c998C>T (p. Ala333Val), which occurs in over half of all known CDG-Ic patients. The frequency of c.391T>C (p.Tyr131His) in the US population, is 0.0214, suggesting that homozygotes would occur at a rate of& tilde;1:2,200. We identified one patient with typical CDG-Ic symptoms and a homozygous p.Tyr131His alteration in ALG6. However, in contrast to most CDG patients, her LLO and plasma transferrin glycosylation appeared normal. Thus, it is unclear whether c.391T>C causes CDG-Ic or contributes to the symptoms. Genotyping additional patients with CDG-like symptoms will be required to resolve this issue.
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PMID:Identification of a frequent variant in ALG6, the cause of Congenital Disorder of Glycosylation-Ic. 1451 65

Congenital disorders of glycosylation (CDG) are an expanding group of inherited metabolic diseases with multisystem involvement. ALG6-CDG (CDGIc) is an endoplasmatic reticulum defect in N-glycan assembly. It is usually milder than PMM2-CDG (CDG-Ia) and so is its natural course. It is characterized by psychomotor retardation, seizures, ataxia, and hypotonia. In contrast to PMM2-CDG (CDGIa), there is no cerebellar hypoplasia. Cardiomyopathy has been reported in a few CDG types and in a number of patients with unexplained CDG. We report an 11 year old Saudi boy with severe psychomotor retardation, seizures, strabismus, inverted nipples, dilated cardiomyopathy, and a type 1 pattern of serum transferrin isoelectrofocusing. Phosphomannomutase and phosphomannose isomerase activities were normal in fibroblasts. Full gene sequencing of the ALG6 gene revealed a novel mutation namely c.482A>G (p.Y161C) and heterozygosity in the parents. This report highlights the importance to consider CDG in the differential diagnosis of unexplained cardiomyopathy.
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PMID:A novel mutation and first report of dilated cardiomyopathy in ALG6-CDG (CDG-Ic): a case report. 2039 63

Congenital disorders of glycosylation (CDG) are inherited metabolic diseases affecting N-linked glycosylation pathways with variable clinical presentations characterized by psychomotor retardation, seizures, ataxia and hypotonia. CDG-Ic is caused by mutation in the ALG6 gene encoding alpha-1,3-glucosyltransferase. We present a 9-year-old girl diagnosed as having CDG-Ic. She developed severe psychomotor retardation, epileptic seizures, muscle hypotonia, strabismus and some dysmorphic features without inverted nipples or fat pads. She showed a fluctuating serum transaminase level with or without some infection, and a characteristically low level of antithrombin III. MR imaging of the brain at age 2years demonstrated the lower limit of normal myelination, mild atrophy of the cerebrum, and mild hypoplasia of the brainstem and cerebellum. The patient exhibited a CDG type I pattern of serum transferrin on isoelectric focusing and mass spectrometric profiling. Sequence analysis of the ALG6 gene showed two heterozygous mutations, c.998C>T (A333V) and c.1061C>T (P354L). The patient was diagnosed as having CDG-Ic with a novel mutation, making her the first Japanese case. It was suggested that the severe psychomotor retardation in the patient was due to the existence of multiple mutant ALG6 alleles.
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PMID:Congenital disorder of glycosylation type Ic: report of a Japanese case. 2304 53