A Study of Phenotypic Correlation With the Genotypic Status of HTM Regions of KRTHB6 and KRTHB1 Genes in Monilethrix Families of Indian Origin

The study investigated 21 affected individuals from two unrelated Indian families with monilethrix, identifying a point mutation (g.4624G>A) in the HTM motif of the KRTHB6 gene, leading to an E413K change. Family 1 exhibited a severe, localized hair defect with a beaded appearance on the scalp, while Family 2 showed a generalized, moderate hair defect without beading. These phenotypic differences correlated with distinct genotypes in the KRTHB1 gene's HTM region. The E413K mutation in KRTHB6 was not found in 150 unaffected controls, highlighting its potential role in the disease. This was the first report of such mutations in Indian monilethrix cases and the first documentation of SNPs in the KRTHB1 gene.