Mapping one form of autosomal dominant postaxial polydactyly type A to chromosome 7p15-q11.23 by linkage analysis.
Postaxial polydactyly type-A (PAP-A) in humans is an autosomal dominant trait characterized by an extra digit in the ulnar and/or fibular side of the upper and/or lower extremities. The extra digit is well formed and articulates with the fifth, or extra, metacarpal/metatarsal, and thus it is usually functional. In order to map the gene responsible for PAP-A, we studied a five-generation Indian family of 37 individuals (15 of whom were affected). A genomewide search with highly informative polymorphic markers on part of the pedigree showed linkage between the PAP-A phenotype and markers on chromosome 7p15-q11.23 (no crossovers were found with D7S526, D7S795, D7S528, D7S521, D7S691, D7S667, D7S478, D7S1830, D7S803, D7S801, or ELN). The highest LOD score was obtained with marker D7S801 (zeta max = 4.21; theta = 0). Haplotype analysis enabled the mapping of the PAP-A phenotype in this family between markers D7S2848 and D7S669. Analysis of additional families with PAP-A will narrow down the critical genomic region, facilitate positional cloning of the PAP-A gene, and/or uncover potential genetic heterogeneity.
Radhakrishna
U
U
Department of Genetics and Microbiology, Geneva Medical School, Switzerland.
Blouin
J L
JL
Mehenni
H
H
Patel
U C
UC
Patel
M N
MN
Solanki
J V
JV
Antonarakis
S E
SE
D002874:Chromosome Mapping; D002897:Chromosomes, Human, Pair 7; D004247:DNA; D005260:Female; D005799:Genes, Dominant; D008040:Genetic Linkage; D006801:Humans; D008297:Male; D010375:Pedigree; D017689:Polydactyly / Q000000981:diagnostic imaging / Q000235:genetics*; D011110:Polymorphism, Genetic; D011859:Radiography
D004247:DNA