Witchel S F, Lee P A
Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh, Pennsylvania 15213, USA.
Am J Med Genet. 1998 Apr 1;76(4):337-42.
Congenital adrenal hyperplasia due to 21-hydroxylase deficiency is a common autosomal-recessive disorder. To ascertain carrier status, adrenocorticotropin (ACTH) stimulation tests are often used. To determine the sensitivity of ACTH stimulation to detect heterozygotes and to correlate stimulated 17-hydroxyprogesterone responses with molecular genotype, we compared molecular genetic analysis of the 21-hydroxylase (CYP21) gene with 17-hydroxyprogesterone responses at 30 min in 51 individuals. Molecular genotype analysis and ACTH stimulation tests were performed in healthy volunteers (n = 20) and relatives of patients with congenital adrenal hyperplasia (n = 31). Polymerase chain reaction (PCR) amplification, single-strand conformational polymorphism (SSCP) analysis, allele-specific oligonucleotide hybridization (ASOH) analysis, and restriction fragment length polymorphism (RFLP) analysis were utilized to screen for 14 CYP21 mutations which account for >90% of the mutations associated with 21-hydroxylase deficiency. Molecular genotype analysis classified 28 individuals as heterozygotic carriers and 23 individuals as normal for all mutations tested. As a group, the heterozygotes had significantly greater stimulated 17-hydroxyprogesterone responses at 10 and 30 min (P < 0.0005). However, on an individual basis, 14/28 (50%) genotyped heterozygotic carriers had stimulated 17-hydroxyprogesterone concentrations, 17-hydroxyprogesterone/cortisol ratios, and 17-hydroxyprogesterone incremental elevations indistinguishable from the genotyped normal individuals. Thus, a normal 17-hydroxyprogesterone response to ACTH stimulation testing does not exclude carrier status for 21-hydroxylase deficiency. Molecular genotype analysis is a more reliable method to determine 21-hydroxylase heterozygotes.
21-羟化酶缺乏所致先天性肾上腺皮质增生症是一种常见的常染色体隐性疾病。为确定携带者状态，常采用促肾上腺皮质激素（ACTH）刺激试验。为测定ACTH刺激检测杂合子的敏感性，并将刺激后的17-羟孕酮反应与分子基因型相关联，我们比较了51例个体的21-羟化酶（CYP21）基因分子遗传学分析与30分钟时的17-羟孕酮反应。对健康志愿者（n = 20）和先天性肾上腺皮质增生症患者的亲属（n = 31）进行了分子基因型分析和ACTH刺激试验。利用聚合酶链反应（PCR）扩增、单链构象多态性（SSCP）分析、等位基因特异性寡核苷酸杂交（ASOH）分析和限制性片段长度多态性（RFLP）分析，筛选出14种CYP21突变，这些突变占与21-羟化酶缺乏相关突变的90%以上。分子基因型分析将28例个体分类为杂合子携带者，23例个体在所有检测突变中为正常。总体而言，杂合子在10分钟和30分钟时刺激后的17-羟孕酮反应显著更高（P < 0.0005）。然而，就个体而言，14/28（50%）基因分型的杂合子携带者的刺激后17-羟孕酮浓度、17-羟孕酮/皮质醇比值和17-羟孕酮增量升高与基因分型正常个体无差异。因此，ACTH刺激试验中17-羟孕酮反应正常并不能排除21-羟化酶缺乏的携带者状态。分子基因型分析是确定21-羟化酶杂合子的更可靠方法。
