GENE MUTATION IN 21-HYDROXYLASE DEFICIENCY

所有形式的21-羟基酶缺乏，缺盐，单纯性雄化，和 晚发型，共用一个共同的基因座(CYP21B)在第III类区域 串联复制中6号染色体上的主要组织相容性复合体 带有假基因(CYP21A型)。基因缺失、转换和点 已经描述了21-羟基酶缺乏症患者的突变。 这种临床表型和突变事件的异质性表明 21-羟基酶的表达有很大的差异 活动。 来评估我们的假设，即基因表达的更大干扰 导致21-羟基酶活性的更大幅度下降，表现为 严重的表型疾病，我们建议相关，频率 检测到21-羟基酶基因结构部分的变化 通过聚合酶链式反应和基因组DNA扩增 斑点杂交分析，包括临床表型、临床严重程度和 17-羟孕酮对合成ACTH的反应 受影响的家庭，因为缺陷可能发生在 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。 为了确认检测到的序列改变影响酶活性， PKCRH-2基因在COS-7猴体内的表达 肾细胞转化率的测定 将17-羟基[14C]孕酮转化为14C-11脱氧皮质醇。 表达酶活性的结果将与表型和 用来确定表型是否能预测基因。

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.