TLDR KAP genes show significant genetic variability, but its impact on hair traits is unclear.
The 2005 study investigated size polymorphisms in human keratin-associated protein (KAP) genes, essential for hair structure. Researchers identified 85 KAP gene loci on chromosomes 17, 21, and 11, divided into 21 families. They found significant genetic diversity, especially in the ultrahigh sulfur KAP4 gene, due to intragenic deletions or duplications, particularly in Japanese populations, suggesting a founder effect. Despite the complexity and number of KAP genes, the functional impact of these polymorphisms on hair structure was still unclear, necessitating further research to understand their effects across different populations.
27 citations,
June 2005 in “The journal of investigative dermatology/Journal of investigative dermatology” The study found that variations in hair protein genes are likely due to evolutionary deletions or duplications.
62 citations,
January 2004 in “The journal of investigative dermatology/Journal of investigative dermatology” A second domain of high sulfur KAP genes on chromosome 21q23 is crucial for hair structure.
17 citations,
June 2003 in “The journal of investigative dermatology. Symposium proceedings/The Journal of investigative dermatology symposium proceedings” Mutations in hKAP1 genes may cause hereditary hair disorders.
100 citations,
December 2002 in “Journal of biological chemistry/The Journal of biological chemistry” Researchers mapped and categorized specific keratin-associated protein genes on human chromosome 21q22.1.
48 citations,
November 2002 in “Journal of biological chemistry/The Journal of biological chemistry” Genetic variations in hair keratin proteins exist but don't significantly affect hair structure.
24 citations,
February 2002 in “The journal of investigative dermatology/Journal of investigative dermatology” Two new proteins, hKAP1.6 and hKAP1.7, are found in the hair follicle cortex.
98 citations,
June 2001 in “Journal of biological chemistry/The Journal of biological chemistry” A cluster of sulfur-rich hair protein genes was found on chromosome 17.
98 citations,
May 2016 in “Genes” Understanding wool keratin-associated proteins in sheep can help improve wool quality through selective breeding.
6 citations,
April 2005 in “Journal of dermatological science” The study found nine new hair protein genes in human hair follicles.
62 citations,
January 2004 in “The journal of investigative dermatology/Journal of investigative dermatology” A second domain of high sulfur KAP genes on chromosome 21q23 is crucial for hair structure.
14 citations,
April 2016 in “PloS one” The KRTAP11-1 gene promoter is crucial for specific expression in sheep wool cortex.
10 citations,
November 2021 in “International journal of molecular sciences” Sheep and goat hair fibers are complex due to keratin-associated proteins, which are important for fiber properties and growth.