Chimeric CYP21P/CYP21 and TNXA/TNXB genes in the RCCX module.
Two types of chimeric RCCX modules found in chromosome 6p21.3 are the chimeras CYP21P/CYP21 and TNXA/TNXB. The CYP21P-specific sequence of chimera CYP21P/CYP21 has the 5'-end in common, but differs in the 3'-end of CYP21-specific genes. The sequence organization of the gene array is C4A-CYP21P/CYP21-TNXB, whereas chimera TNXA/TNXB is caused by a CYP21 deletion, and a partial TNXB replaced by the TNXA gene shows the C4A-CYP21P-TNXA/TNXB sequence. Therefore, chimeras CYP21P/CYP21 and TNXA/TNXB are two distinct hybrid genes produced in the RCCX module in HLA class III. In addition, the haplotype of CYP21 with chimera CYP21P/CYP21 causes 21-hydroxylase deficiency in congenital adrenal hyperplasia (CAH), while chimera TNXA/TNXB is associated with Ehlers-Danols syndrome as well as CAH.
Lee
Hsien-Hsiung
HH
Department of Medical Research, Mackay Memorial Hospital, No. 45, Min-Sheng Road, Tanshui, Taipei 251, Taiwan, ROC. hhlee@ms1.mmh.org.tw
D000312:Adrenal Hyperplasia, Congenital / Q000235:genetics*; D002896:Chromosomes, Human, Pair 6 / Q000235:genetics*; D004535:Ehlers-Danlos Syndrome / Q000235:genetics*; D005006:Ethnicity / Q000235:genetics*; D040461:Gene Components; D017353:Gene Deletion; D006239:Haplotypes / Q000235:genetics; D006801:Humans; D008285:Major Histocompatibility Complex / Q000235:genetics; D009154:Mutation / Q000235:genetics; D011506:Proteins / Q000235:genetics*; D011544:Pseudogenes / Q000235:genetics; D011995:Recombination, Genetic / Q000235:genetics*; D013255:Steroid 21-Hydroxylase / Q000235:genetics*; D019063:Tenascin
D011506:Proteins; C074149:TNXA protein, human; D019063:Tenascin; D013255:Steroid 21-Hydroxylase