Postaxial Polydactyly (PAP) is characterized by fifth digit duplication in hands and/or feet. Two types of PAP including PAP-A, representing the development of well-formed extra digit, and PAP-B, representing the presence of rudimentary fifth digit, have been described. Both isolated and syndromic forms of PAP have been reported. Isolated forms of PAP usually segregate as an autosomal dominant trait and to date four loci have been identified. In the present study, we have described mapping of the first locus of autosomal recessive PAP type A on chromosome 13q13.3–13q21.2 in a consanguineous Pakistani family. In family with autosomal dominant forms of postaxial polydactyly, most of the affected individuals exhibit features representing type A PAP (Zhao et al.,2002; Galjaardet et al.,2003). In the respected family mapped on chromosome 13q13.3– 13q21.2, affected individuals showed the additional features of postaxial polydactyly.Several locus of causative genes are involved in this disease. To check the specified locus we use several microsatellite markers (D13S1246, D13S218, D13S1288, D13S1233, D13S263, D13S1312, D13S153, D13S328, D13S119, D13S632, D13S889,D4S90, D4S2936, D4S111, D4S43, D4S16114, D4S95, D4S127, D4S126, D4S179, D4S432, D4S2957, D4S431, D4S2366, D4S2935, D4S3007, D4S412, D4S3023, D4S2285 ). All the affected individuals showed no homozygosity. Genetic mapping of all the affected individuals showed that noval genes are responsible for the disease. In future, we will work on and try to find out the causative genes.
Microsatellite Markers for Genetic Mapping in the Chicken