Characterization of a 190-Kilobase Pair Domain of Human Type I Hair Keratin Genes

The study characterized a 190-kilobase pair domain of human type I hair keratin genes, identifying 10 hair keratin genes, including one transcribed pseudogene and one orphan exon. These genes, sized 4-7 kbp with intergenic distances of 5-8 kbp, were organized into three subclusters based on sequence homologies. All genes, including the pseudogene, were expressed in the human hair follicle, with the pseudogene containing a premature stop codon and exhibiting aberrant splicing. Evolutionary analysis suggested an early divergence of hair keratin genes from cytokeratin genes, followed by segregation into the three subclusters. The study concluded that the 190-kbp domain likely contained the entire complement of human type I hair keratin genes, providing insights into their genomic organization and evolutionary relationships.