21-羟化酶缺乏症是先天性肾上腺增生的最常见形式,主要由CYP21A2基因突变引起。另一方面,CYP17A1基因内的突变导致17α-羟化酶/17,20-裂解酶缺乏。17-OH缺乏症的稀缺性值得注意,占所有先天性肾上腺增生病例的1%以下。男病人,出生于一级堂兄婚姻,表现出几种症状,包括左侧未降睾丸,小阴茎,阴茎弦,左感神经性听力损失,和男性乳房发育症。他在13.5岁时报告微阴茎是一个问题。他的激素水平显示血清17-羟孕酮水平很高,黄体酮,和孕烯醇酮。在这种情况下,具有46XY核型,由于生殖器模糊和非典型的激素谱,人们对细胞色素P450氧化还原酶缺乏症产生了怀疑。分析揭示了CYP21A2和CYP17A1基因中两种不同的纯合和致病性变体。值得注意的是,盐皮质激素前体升高,而皮质醇和性类固醇前体在高剂量(250mcg)ACTH刺激试验期间下降。突变c.1169C>G(p.Thr390Arg)在CYP17A1中,这是文献中的第二个文献案例,脱颖而出,由于其独特的配套功能。CYP21A2和CYP17A1中发生的突变导致完全或部分酶缺乏。并且在类固醇生成途径内的两个不同酶系统中检测到纯合突变是值得注意的。
21-hydroxylase deficiency stands as the most prevalent form of congenital adrenal hyperplasia, primarily resulting from mutations in the CYP21A2 gene. On the other hand, mutations within the
CYP17A1 gene lead to 17α-hydroxylase/17,20-lyase enzyme deficiencies. The scarcity of 17-OH deficiency is noteworthy, accounting for less than 1% of all congenital adrenal hyperplasia cases. The male patient, born from a first-degree cousin marriage, exhibited several symptoms, including left undescended testis, micropenis, penile chord, left sensorineural hearing loss, and gynecomastia. He reported micropenis as a concern at the age of 13.5 years. His hormone profile revealed high levels of serum 17-hydroxyprogesterone, progesterone, and pregnenolone. In this case with a 46 XY karyotype, suspicions arose regarding Cytochrome P450 oxidoreductase deficiency due to ambiguous genitalia and an atypical hormone profile. Analysis unveiled two distinct homozygous and pathogenic variants in the CYP21A2 and
CYP17A1 genes. Notably, mineralocorticoid precursors escalated, while cortisol and sex steroid precursors decreased during the high (250 mcg) dose ACTH stimulation test. The mutation c.1169C > G (p.Thr390Arg) in
CYP17A1, which is the second documented case in literature, stands out due to its unique set of accompanying features. Mutations occurring in CYP21A2 and
CYP17A1 result in complete or partial enzyme deficiencies, and the detection of homozygous mutations in two different enzyme systems within the steroidogenic pathway is noteworthy.