A new locus for autosomal recessive RP (RP29) mapping to chromosome 4q32-q34 in a Pakistani family

Citation
A. Hameed et al., A new locus for autosomal recessive RP (RP29) mapping to chromosome 4q32-q34 in a Pakistani family, INV OPHTH V, 42(7), 2001, pp. 1436-1438
Citations number
7
Language
INGLESE
art.tipo
Article
Categorie Soggetti
da verificare
Journal title
INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE
ISSN journal
0146-0404 → ACNP
Volume
42
Issue
7
Year of publication
2001
Pages
1436 - 1438
Database
ISI
SICI code
0146-0404(200106)42:7<1436:ANLFAR>2.0.ZU;2-E
Abstract
PURPOSE. To map the disease locus in a six-generation, consanguineous Pakis tani family with autosomal recessive retinitis pigmentosa (arRP). All affec ted individuals had pigmentary retinopathy associated with symptoms of nigh t blindness and the loss of peripheral visual fields by the age of 20 years , loss of central vision between the ages of 25 and 30 years, and complete blindness between the ages of 40 and 50 years. METHODS. Genomic DNA from family members was typed for alleles at known pol ymorphic genetic markers using polymerase chain reaction. Alleles were assi gned to individuals, which allowed calculation of LOD scores using the prog rams Cyrillic (http://www.cyrillicsoftware.com) and MLINK (Cherwell Scienti fic Publishing Ltd., Oxford, UK). The genes for membrane glycoprotein (M6a) and chloride channel 3 (CLCN3) were analyzed by direct sequencing for muta tions. RESULTS. A new locus for arRP (RP29) has been mapped to chromosome 4q32-q34 . A maximum two-point LOD score of 3.76 was obtained for the marker D4S415, with no recombination. Two recombination events in the pedigree positioned this locus to a region flanked by markers D4S621 and D4S2417. A putative r egion of homozygosity by descent was observed between the loci D4S3035 and D4S2417, giving a probable disease interval of 4.6 cM. Mutation screening o f two candidate genes, M6a and CLCN3, revealed no disease-associated mutati ons. CONCLUSIONS. The results suggest that the arRP phenotype maps to a new locu s and is due to a mutated gene within the 4q32-q34 chromosomal region.