GENE MUTATION IN 21-HYDROXYLASE DEFICIENCY

所有形式的21-羟化酶缺乏症，失盐，单纯男性化， 晚发型，在III类区域共享一个共同的基因位点（CYP 21 B）， 串联重复中6号染色体上的主要组织相容性复合体 假基因（CYP 21 A）。 基因缺失、转换和点突变 在21-羟化酶缺乏的患者中已经描述了突变。 临床表型和突变事件的异质性表明 21-羟化酶的表达有很大的差异， 活动 为了验证我们的假设， 导致21-羟化酶活性的更大降低，表现为 严重的表型疾病，我们建议相关，频率 检测到21-羟化酶基因结构部分的改变 通过利用聚合酶链式反应的基因组DNA扩增， 斑点杂交分析，与临床表型，临床严重程度和 17-羟孕酮对合成ACTH的反应，在我们的人群中， 受影响的家庭由于缺陷可能发生在监管部分的 基因，我们将检查调控部分，如果没有明显的 基因结构部分的核苷酸序列改变。 为了证实检测到的序列改变影响酶活性， pKCRH-2基因转染COS-7猴后的表达 肾细胞转化率测定 将17-羟基[14 C]孕酮转化为14 C-11脱氧皮质醇。 表达的酶活性的结果将与表型相关， 基因型以确定表型是否预测基因型。

All forms of 21-hydroxylase deficiency, salt-losing, simple virilizing, and late-onset, share a common gene locus (CYP21B) in the class III region of the major histocompatibility complex on chromosome 6 in tandem duplication with a pseudogene (CYP21A). Gene deletions, conversions, and point mutations have been described in patients with 21-hydroxylase deficiency. This heterogeneity of clinical phenotypes and mutational events suggests that there is a wide variation in the expression of 21-hydroxylase activity. To evaluate our hypothesis that greater disturbance of gene expression leads to greater decrease in 21-hydroxylase activity manifested as more severe phenotypic disease, we propose to correlate ,the frequency of alterations in the structural portion of the 21-hydroxylase gene, detected through genomic DNA amplification utilizing polymerase chain reaction and dot-blot analysis, with the clinical phenotype, clinical severity and 17-hydroxyprogesterone response to synthetic ACTH, in our population of affected families Since defects may occur in the regulatory portion of the gene, we will examine the regulatory portion if there are no apparent nucleotide sequence alterations in the structural portion of the gene. To confirm that detected sequence alterations affect enzyme activity, expression of the altered sequence in pKCRH-2 transfected into COS-7 monkey kidney cells with determination of conversion of 17-hydroxy[14C]progesterone into 14C-lldeoxycortisol will be performed. Results of expressed enzyme activity will be correlated with phenotype and genotype to determine if phenotype predicts genotype.