3 β -羟基甾体脱氢酶缺乏症分子基础的新见解:来自7个新家族的11名患者的HSD3B2基因中鉴定了8个突变，并比较了25个突变酶的功能特性。
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Moisan AM, Ricketts ML, Tardy V, Desrochers M, Mebarki F, Chaussain JL, Cabrol S, Raux-Demay MC, Forest MG, Sippell WG, Peter M, Morel Y, Simard J
3 β -羟基甾体脱氢酶缺乏症分子基础的新见解:来自7个新家族的11名患者的HSD3B2基因中鉴定了8个突变，并比较了25个突变酶的功能特性。
中华内分泌杂志，1999;12(12):439 - 448。
- PubMed ID
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10599696 (PubMed视图］
- 摘要
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典型的3beta-羟基类固醇脱氢酶/delta5-delta4异构酶(3betaHSD)缺乏症是一种先天性肾上腺增生症，由HSD3B2基因突变导致肾上腺和性腺的类固醇生成受损，并导致两性不同程度的盐浪费和遗传男性外生殖器的不完全雄性化。为了鉴定来自7个典型3betaHSD缺陷新家族的11例患者HSD3B2基因的分子损伤，我们通过直接测序确定了该基因整个编码区和外显子-内含子剪接边界的完整核苷酸序列。其中5个家族被送到了莫雷尔在法国的分子诊断实验室，而另外两个家族则由彼得在德国的小组调查。功能特征研究由加拿大的Simard小组进行。在293个细胞中通过定点诱变产生的每个突变重组蛋白进行瞬时表达后，通过用10 nM [14C]-DHEA作为底物培养完整细胞来评估25个突变对酶活性的影响。突变蛋白的稳定性已经使用北方和西方印迹分析的组合进行了研究，以及使用兔网织红细胞裂解物的体外转录/翻译试验。本报告描述了在7个患有典型3betaHSD缺陷的新家族中鉴定的8个突变，从而将这种常染色体隐性遗传病涉及的已知HSD3B2突变数量增加到31个(1个剪接，1个帧内缺失，3个无义，4个移码和22个错义突变)。除了在这些新家族中报道的突变外，我们还首次研究了先前报道的错义突变和或序列变异的功能意义，即A82T、A167V、L173R、L205P、S213G和K216E、P222H、T259M和T259R，这些突变以前没有功能特征。此外，还将它们的作用与之前报道的10种突变酶进行了比较，以提供更一致和全面的研究。目前的结果与预测一致，即由于典型的3betaHSD缺乏症导致的严重盐浪费型CAH患者的肾上腺和性腺中没有功能性3betaHSD 2型同工酶的表达。 Whereas the nonsalt-losing form also results from missense mutation(s) in the HSD3B2 gene, which cause an incomplete loss in enzyme activity, thus leaving sufficient enzymatic activity to prevent salt wasting. The functional data described in the present study concerning the sequence variants A167V, S213G, K216E and L236S, which were detected with premature pubarche or hyperandrogenic adolescent girls suspected to be affected from nonclassical 3betaHSD deficiency, coupled with the previous studies reporting that no mutations were found in both HSD3B1 and/or HSD3B2 genes in such patients strongly support the conclusion that this disorder does not result from a mutant 3betaHSD isoenzyme. The present study provides biochemical evidence supporting the involvement of a new molecular mechanism in classical 3betaHSD deficiency involving protein instability and further illustrates the complexity of the genotype-phenotype relationships of this disease, in addition to providing further valuable information concerning the structure-function relationships of the 3betaHSD superfamily.