Introduction

11β-hydroxylase deficiency is the second most common form of congenital adrenal hyperplasia (CAH), accounting for 5–8% of all cases. It is an autosomal recessive enzyme defect that impairs the biosynthesis of cortisol and aldosterone. Mutation of the CYP11B1 gene on chromosome 8q22 causes partial or total reduction of enzyme activity. Clinical manifestations of 11β-hydroxylase deficiency include hypertension, and other signs related to overproduction of mineralocorticoids, and virilisation. Here, we report on a case of 11β-hydroxylase deficiency detected by urine steroid metabolome profiling.

Case Subject

The patient, a 3-month-old male, suffered from truncus arteriosus type I (congenital cardiovascular anomaly) and also presented with hyperpigmentation. An endocrinology consultation was sought and biochemical and molecular testing was conducted.

Results

The patient’s urine steroid metabolome, as analysed by GC-MS, showed high excretion of tetrahydrodeoxycortisol (THS) and a THS/(THE + THF + 5αTHF) ratio of 2.3, which was higher than normal. Diagnosis of 11β-hydroxylase deficiency was confirmed by mutation analysis of the CYP11B1 gene.

Conclusion

Analysis of the urine steroid metabolome by GC-MS can be used to assist in diagnosis of 11β-hydroxylase deficiency. We recommend consideration of urine steroid analysis as a first-line test in the diagnosis of CAH.

中文翻译：

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使用气相色谱-质谱法通过尿液类固醇代谢组分析检测 11β-羟化酶缺乏症

 介绍

11β-羟化酶缺乏症是先天性肾上腺增生 (CAH) 的第二常见形式，占所有病例的 5-8%。它是一种常染色体隐性酶缺陷，会损害皮质醇和醛固酮的生物合成。染色体 8q22 上 CYP11B1 基因的突变会导致酶活性部分或全部降低。 11β-羟化酶缺乏症的临床表现包括高血压以及与盐皮质激素过量产生和男性化相关的其他体征。在这里，我们报告了一例通过尿液类固醇代谢组分析检测到的 11β-羟化酶缺乏症的病例。

 案例主题

该患者是一名 3 个月大的男性，患有 I 型动脉干（先天性心血管异常），并伴有色素沉着过度。寻求内分泌咨询并进行生化和分子检测。

 结果

GC-MS 分析显示，患者尿液类固醇代谢组显示四氢脱氧皮质醇 (THS) 排泄量较高，THS/(THE + THF + 5αTHF) 比率为 2.3，高于正常值。 11β-羟化酶缺乏症的诊断通过 CYP11B1 基因的突变分析得到证实。

 结论

通过 GC-MS 分析尿液类固醇代谢组可用于辅助诊断 11β-羟化酶缺乏症。我们建议考虑将尿液类固醇分析作为诊断 CAH 的一线测试。