Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.4.2.8 (hypoxanthine-guanine phosphoribosyltransferase)
 2,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The mutant frequency at the hypoxanthine-guanine phosphoribosyltransferase locus in peripheral blood lymphocytes was measured for 254 atomic bomb survivors (171 exposed and 83 control survivors) by a colony assay using recombinant human interleukin-2. Weak but significant effects were detected for atomic bomb radiation dose and smoking status at the time of examination but not for age and sex. However, the slope of the dose-response curve is quite small, and the smoking effect would not have been significant without the inclusion of data from just three individuals with extremely high mutant frequencies. The weakness of the dose response is at least partly due to the time lapse of 50 years since radiation exposure. Among the 254 survivors, 23 had chromosome aberration data in lymphocytes and the dose response was highly significant. However, the correlation between the mutant frequency and the proportion of cells with aberrations was not significant. It was concluded that the lymphocyte mutation assay is presently not sensitive enough for biological dosimetry of radiation exposure in the survivors.
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PMID:Mutant frequency at the HPRT locus in peripheral blood T-lymphocytes of atomic bomb survivors. 760

DNA markers on the X chromosome were used to map the locus for an unusual form of X-linked recessive hereditary motor and sensory neuropathy with associated deafness and mental retardation in a three-generation family that was originally reported by Cowchock et al. (Am, J. Hum. Genet. 35: 85A, 1993; Am. J. Med. Genet. 20: 307-315, 1985). This family included seven affected males, three obligate carrier females, and four unaffected males. The patients were severely affected within the first few years of life with distal weakness, muscle atrophy, sensory loss, areflexia, pes cavus, and hammer toes. Five of the seven affected males showed associated deafness, and three of these five individuals also presented with mental retardation or social developmental delay. Motor nerve conduction velocities in affected males were normal to mildly delayed, and sensory conduction was markedly abnormal. Heterozygous females were asymptomatic. Close linkage to the Xg blood group locus (Xp22) and the PGK locus (Xq13) was previously excluded in this family, while weak linkage of the disease gene to DXYS1 (XQ21.3) was suggested. Our current linkage studies and haplotype analysis of 19 microsatellite markers on the long arm of the X chromosome demonstrate that DXS425 (Xq24) and HPRT (Xq26.1) are flanking markers and that the disease gene is closely linked to the markers DXS1122, DXS994, DXS737, DXS1206, and DXS1047.
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PMID:A locus for axonal motor-sensory neuropathy with deafness and mental retardation maps to Xq24-q26. 866 89