Congenital adrenal hyperplasia caused by mutant P450 oxidoreductase and human androgen synthesis: analytical study
Congenital adrenal hyperplasia caused by mutant P450 oxidoreductase and human androgen synthesis: analytical study
复制标题
DOI：
10.1016/s0140-6736(04)16503-3
复制
发表时间：
2004-06-26
期刊：
影响因子：
168.9
通讯作者：
Shackleton, CHL
中科院分区：
文献类型：
--
作者：
Arlt, W;Walker, EA;Shackleton, CHL
先天性肾上腺皮质增生伴P450 C17和P450 C21明显联合缺乏与类固醇代谢产物的积累有关，表明17 α-羟化酶和21-羟化酶活性受损。然而，在编码这些P450酶的CYP 17和CYP 21基因中没有报道突变。受影响的女孩出生时生殖器模糊，但他们的循环雄激素低，男性化没有进展。我们的目的是调查潜在的分子基础，先天性肾上腺皮质增生症与明显结合P450 C17和P450 C21缺陷的影响childhen.Methods我们做了人类基因编码的P450氧化还原酶，一种酶，是重要的电子转移从NADPH到P450 C17和P450 C21的序列分析。我们研究了两个不相关的家庭，共有三名受影响的儿童和100名健康对照。野生型和突变体P450氧化还原酶蛋白的细菌表达，纯化，并测定细胞色素c还原酶activity.Findings我们确定了4个突变编码的单个氨基酸的变化P450氧化还原酶。所有患者均为复合杂合子，而他们的父母和一名未受影响的兄弟姐妹仅在一个等位基因中存在突变。相比之下，在对照组中未观察到突变。重组突变蛋白的细菌表达显示酶活性不足或降低。解释这种形式的先天性肾上腺皮质增生的分子发病机制是由编码P450氧化还原酶的基因突变引起的。这种酶的缺乏可能表明人类雄激素合成的替代途径，只存在于胎儿期，这解释了产前雄激素过多和产后雄激素缺乏的组合。
Background Congenital adrenal hyperplasia with apparent combined P450C17 and P450C21 deficiency is associated with accumulation of steroid metabolites, indicating impaired activity of 17alpha-hydroxylase and 21-hydroxylase. However, no mutations have been reported in the CYP17 and CYP21 genes, which encode these P450 enzymes. Affected girls are born with ambiguous genitalia, but their circulating androgens are low, and virilisation does not progress. We aimed to investigate the underlying molecular basis of congenital adrenal hyperplasia with apparent combined P450C17 and P450C21 deficiency in affected children.Methods We did sequence analysis of the human gene encoding P450 oxidoreductase, an enzyme that is important in electron transfer from NADPH to P450C17 and P450C21. We studied two unrelated families with a total of three affected children and 100 healthy controls. Wild-type and mutant P450 oxidoreductase proteins were bacterially expressed, purified, and assayed for cytochrome c reductase activity.Findings We identified four mutations encoding single aminoacid changes in P450 oxidoreductase. All patients were compound heterozygotes, whereas their parents and an unaffected sibling harboured a mutation in only one allele. By contrast, no mutations were noted in the controls. Bacterial expression of recombinant mutant proteins revealed deficient or reduced enzyme activity.Interpretation Molecular pathogenesis of this form of congenital adrenal hyperplasia is caused by mutations in the gene encoding P450 oxidoreductase. Deficiency of this enzyme could suggest an alternative pathway in human androgen synthesis, present only in fetal life, which explains the combination of antenatal androgen excess and postnatal androgen deficiency.