Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0025362 (mental retardation)
 15,878 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

M6 is a neuronal membrane glycoprotein that may have an important role in neural development. This molecule was initially defined by a monoclonal antibody that affected the survival of cultured cerebellar neurons and the outgrowth of neurites. The nature of the antigen was discovered by expression cDNA cloning using this monoclonal antibody. Two distinct murine M6 cDNAs (designated M6a and M6b) whose deduced amino acid sequences were remarkably similar to that of the myelin proteolipid protein were previously isolated. We have isolated partial human cDNA and genomic clones encoding M6a and M6b and have characterized them by restriction mapping, Southern hybridization with cDNA probes, and sequence analysis. We have localized these genes within the human genome by FISH (fluorescence in situ hybridization). The human M6a gene is located at 4q34, and the M6b gene is located at Xp22.2. A number of human neurological disorders have been mapped to the Xp22 region, including Aicardi syndrome (MIM 304050), Rett syndrome (MIM 312750), X-linked Charcot-Marie-Tooth neuropathy (MIM 302801), and X-linked mental retardation syndromes (MRX1, MIM 309530). This raises the possibility that a defect in the M6b gene is responsible for one of these neurological disorders.
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PMID:Chromosomal mapping of the human M6 genes. 866 Oct 15

Rambam-Hasharon syndrome (RHS) is a newly recognized autosomal recessive inborn error in fucose metabolism. Mental retardation, short stature, coarse facies, and recurrent infections are the main clinical findings. Several fucosilated proteoglycans are deficient in these patients. Leukocyte adhesion deficiency type 2 is associated with lack of the membrane glycoprotein sialyl-Lewisx (CD15s). In the red blood cells (RBCs), lack of the membrane glycoprotein H is manifested as a Bombay (Oh) blood type. Two consecutive pregnancies it risk for RHS were monitored during mid-trimester by cordocentesis. One fetus expressed H substance and her blood phenotype was O Rh+. The second fetus, a female, was 2 weeks smaller than expected by dates and had the Bombay blood type. The placenta of the affected fetus was small and irregular. This is the first prenatal diagnosis of this syndrome and the first case found in a female. The documentation of the syndrome in patients of both sexes and the parental consanguinity support an autosomal recessive inheritance. Two apparent recombinations between fucosyl-transferase 1 (FUT1, the H gene) and fucosyl-transferase 2 (secretor) are suggestive of non-allelic heterogeneity. We believe that the Bombay phenotype in this family is caused by a mutated gene, other than FUT1, which is causing multiple deficiencies of fucosilated proteoglycans.
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PMID:Prenatal diagnosis of Rambam-Hasharon syndrome. 871 Jul 83

Danon disease (DD) is a rare lysosomal glycogen storage disease with normal acid maltase activity, which is characterised clinically by cardiomyopathy and myopathy, and a variable degree of mental retardation. The causative gene, LAMP2, has been mapped to chromosome Xq24-q25. LAMP2 encodes a lysosome-associated membrane glycoprotein. We identified a novel LAMP2 mutation of the exon 8 splice acceptor site (IVS7-1G --> A) in an affected male and female, which predicts abnormal splicing. Both affected individuals presented solely with hypertrophic cardiomyopathy. Muscle weakness and mental impairment were absent. Diagnosis of Danon disease was established by muscle biopsy, when the male index patient developed transient severe muscle weakness following heart transplantation. Typical biopsy findings were also found in a heart muscle specimen. Demonstration of the LAMP2 mutation in affected male and female siblings is compatible with X-linked dominant inheritance. Danon disease should be actively looked for in cardiomyopathy patients.
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PMID:Identification of a novel LAMP2 mutation responsible for X-chromosomal dominant Danon disease. 1459 34

Danon disease, an extremely rare X-linked dominant disorder, is characterized clinically by hypertrophic cardiomyopathy (HCM), skeletal myopathy, and variable degree of mental retardation with autophagic vacuoles in skeletal and cardiac muscle. Reportedly, Danon disease is caused by a primary deficiency of a major lysosomal membrane glycoprotein, LAMP2 (lysosome-associated membrane protein 2). Here we review the clinical features, molecular genetics, related animal model, and differential diagnosis of Danon disease.
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PMID:Danon disease as a cause of autophagic vacuolar myopathy. 1837 32

The six members of the contactin (CNTN) family of neural cell adhesion molecules are involved in the formation and maintenance of the central nervous system (CNS) and have been linked to mental retardation and neuropsychiatric disorders such as autism. Five of the six CNTNs bind to the homologous receptor protein tyrosine phosphatases gamma (PTPRG) and zeta (PTPRZ), but the biological roles of these interactions remain unclear. We report here the cocrystal structure of the carbonic anhydrase-like domain of PTPRZ bound to tandem Ig repeats of CNTN1 and combine these structural data with binding assays to show that PTPRZ binds specifically to CNTN1 expressed at the surface of oligodendrocyte precursor cells. Furthermore, analyses of glial cell populations in wild-type and PTPRZ-deficient mice show that the binding of PTPRZ to CNTN1 expressed at the surface of oligodendrocyte precursor cells inhibits their proliferation and promotes their development into mature oligodendrocytes. Overall, these results implicate the PTPRZ/CNTN1 complex as a previously unknown modulator of oligodendrogenesis.
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PMID:A complex between contactin-1 and the protein tyrosine phosphatase PTPRZ controls the development of oligodendrocyte precursor cells. 2196 50