Characterization of a First Domain of Human High Glycine-Tyrosine and High Sulfur Keratin-Associated Protein Genes on Chromosome 21q22.1

The study characterized a domain of high glycine-tyrosine and high sulfur keratin-associated protein (KAP) genes on chromosome 21q22.1, identifying 24 KAP genes and 9 pseudogenes. These genes were categorized into families, including six novel ones, and exhibited varied expression patterns in hair follicles. Expression analysis revealed that 17 KAP genes were expressed in the hair cortex, matrix, and cuticle, with some showing distinct expression patterns between scalp and beard hair. The findings highlighted the complexity and diversity of KAP gene expression, suggesting evolutionary differences in KAP gene functionality among species and raising questions about the correlation between mRNA levels and protein synthesis.