A Cluster of 21 Keratin-Associated Protein Genes Within Introns of Another Gene on Human Chromosome 21q22.3

The study identified a cluster of 21 keratin-associated protein (KAP) genes within the introns of the TSPEAR gene on human chromosome 21q22.3, including 16 putative genes and 5 pseudogenes. These genes were categorized into two subfamilies, KRTAP12 and KRTAP18, and were found to be expressed specifically in hair root cells, not in other tissues. The KAP genes were characterized by high sulfur content and produced unspliced transcripts, indicating they were active intronless genes. The transcriptional direction of half of these genes aligned with the TSPEAR gene, suggesting a unique transcription mechanism. This research contributed to understanding the genomic organization of KAP genes, which are crucial for hair growth and formation.