Atrichia With Papular Lesions Resulting From a Novel Insertion Mutation in the Human Hairless Gene

In the 2006 study by Wali et al., researchers identified a novel 11 bp insertion mutation in the HR gene of a consanguineous Pakistani family with 12 individuals affected by congenital atrichia, a condition causing irreversible total hair loss starting after birth. This mutation, found in exon 2 of the HR gene, leads to a frameshift and premature termination codon, which likely causes mRNA decay or truncated protein production. This was the first insertion mutation discovered in the HR gene's coding sequence, providing new insights into the genetic basis of congenital atrichia. The HR gene is believed to encode a zinc-finger transcription factor protein essential for hair follicle regeneration, and the mutation suggests a minimum HR protein size of 125 amino acids, smaller than the previously predicted 445 amino acids based on a 22-bp deletion in exon 3.