{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\n KRTAP5-9 appears to be a member of the hair cuticle ultrahigh‐sulphur keratin–associated protein family that contributes structurally to the formation and integrity of the hair fiber. Detailed mapping studies have established that genes in this family reside in a clustered organization on human chromosome 11, with KRTAP5-9 (previously identified in mapping studies as part of the KRN1 family) being localized to the distal region of 11q13.5 and, by homology, to a similar cluster at 11p15.5 (1,2).\n\n These high‐resolution mapping efforts employed somatic cell hybrid panels, fluorescence in situ hybridization, and radiation hybrid approaches to define the genomic organization of the region, revealing that the gene is embedded within a complex locus where multiple keratin–associated protein genes are arrayed in close proximity (1,3). The precise arrangement of these genes in the genome suggests that KRTAP5-9 likely plays an essential role in constructing the specialized protein matrix of the hair cuticle, contributing to hair strength and resilience.\n "}]}, {"type": "t", "text": "\n "}, {"type": "p", "children": [{"type": "t", "text": "\n In addition to its structural role, alterations in the genomic region containing KRTAP5-9 have been observed in oncogenic amplification events, particularly in breast cancer where discontinuities in amplification have been noted (4). Although its primary function relates to hair biology, these findings imply that the genomic neighborhood of KRTAP5-9 could serve as a marker for complex chromosomal rearrangements associated with human diseases.\n "}]}, {"type": "t", "text": "\n "}, {"type": "p", "children": [{"type": "t", "text": "\n Overall, KRTAP5-9 is implicated in both maintaining the structural integrity of hair through its role in the keratin–associated protein network and, by virtue of its chromosomal context, may be relevant to studies of genomic instability in cancer."}]}, {"type": "t", "text": "\n "}, {"type": "p", "children": [{"type": "fg", "children": [{"type": "fg_fs", "start_ref": "1", "end_ref": "4"}]}, {"type": "t", "text": ""}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "P J MacKinnon, B C Powell, G E Rogers, et al. "}, {"type": "b", "children": [{"type": "t", "text": "An ultrahigh-sulphur keratin gene of the human hair cuticle is located at 11q13 and cross-hybridizes with sequences at 11p15."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Mamm Genome (1991)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1007/BF00350846"}], "href": "https://doi.org/10.1007/BF00350846"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "1724400"}], "href": "https://pubmed.ncbi.nlm.nih.gov/1724400"}]}, {"type": "r", "ref": 2, "children": [{"type": "t", "text": "S Merscher, S Bekri, B de Leeuw, et al. "}, {"type": "b", "children": [{"type": "t", "text": "A 5.5-Mb high-resolution integrated map of distal 11q13."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Genomics (1997)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1006/geno.1996.4460"}], "href": "https://doi.org/10.1006/geno.1996.4460"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "9119371"}], "href": "https://pubmed.ncbi.nlm.nih.gov/9119371"}]}, {"type": "r", "ref": 3, "children": [{"type": "t", "text": "C W Richard, D A Withers, T C Meeker, et al. "}, {"type": "b", "children": [{"type": "t", "text": "A radiation hybrid map of the proximal long arm of human chromosome 11 containing the multiple endocrine neoplasia type 1 (MEN-1) and bcl-1 disease loci."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Am J Hum Genet (1991)"}]}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "1684084"}], "href": "https://pubmed.ncbi.nlm.nih.gov/1684084"}]}, {"type": "r", "ref": 4, "children": [{"type": "t", "text": "P Szepetowski, V Ollendorff, J Grosgeorge, et al. "}, {"type": "b", "children": [{"type": "t", "text": "DNA amplification at 11q13.5-q14 in human breast cancer."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Oncogene (1992)"}]}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "1461654"}], "href": "https://pubmed.ncbi.nlm.nih.gov/1461654"}]}]}]}