Genetic dissection of two Pakistani families with consanguineous localized autosomal recessive hypotrichosis (LAH)

OBJECTIVES Genetic analysis of two consanguineous Pakistani families with localized autosomal recessive hypotrichosis was performed with the goal to establish genotype-phenotype correlation. MATERIALS AND METHODS Genomic DNA extraction had been done from peripheral blood samples. Extracted DNA was then subjected to PCR (polymerase chain reaction) for amplification. Linkage analysis was performed using 8% polyacrylamide gel. Candidate gene was sequenced after gene linkage supported at highly polymorphic microsatellite markers of the diseased region. RESULTS Both families were initially tested for linkage to known genes, which were involved in human hereditary hypotrichosis, by genotyping Highly polymorphic microsatellite markers. Family B showed partial linkage at P2RY5 gene on chromosome 13q14.11-q21.32; hence, all exonic regions and their introns boundaries were subjected to DNA sequencing for any pathogenic mutation. CONCLUSION Both families were tested for linkage by genotyping polymorphic microsatellite markers linked to known alopecia loci. Family A excluded all known diseased regions that is suggestive of some novel chromosomal disorder. However, sequencing of P2RY5 gene in family B showed no pathogenic mutation.