CH-8 Phenotype in Steroid 21-Hydroxylase Deficiency: Fact or Fancy?

[摘要] To the Editor:The defective CYP21A2 1 (cytochrome P450, family 21, subfamily A, polypeptide 2) genes downstream of the TNXB (tenascin XB) gene in congenital adrenal hyperplasia (CAH)2 fall into 3 categories: ( a ) small-scale conversions from the CYP21A1P (cytochrome P450, family 21, subfamily A, polypeptide 1 pseudogene) gene, ( b ) spontaneous mutations, and ( c ) chimeric RCCX modules that include the chimeric CYP21A1P / CYP21A2 genes and chimeric genes of TNXA [tenascin XA (pseudogene)] and TNXB (1). Most of the CYP21A2 mutations of the 15 loci identified thus far are due to small-scale conversions from CYP21A1P during both meiosis and mitosis (2). These mutations account for approximately 70% to 80% of CAH cases. These 15 mutational loci include nucleotide (nt) −126 (C>T), nt −113 (G>A), nt −110 (T>C), nt −103 (A>G), P30L, nt 655 (A/C>G), nt 707–714del, I172N, cluster E6 (1236N, V236E, and M239K), V281L, F306ΛL307insT, Q318X, and R356W. The …

[学科分类] 过敏症与临床免疫学