In 21OHD, some of the accumulated intra-adrenal 17OHP is converted to 21-deoxycortisol (21-deoxy) by 11β-hydroxylase (CYP11B1); 21-deoxy is not elevated in premature infants or in other forms of CAH, and hence is a more specific marker for 21OHD.
In this study, we identified three CYP11B1 (encoding Cytochrome P450 11B1) heterozygous mutations: c.1358G>C (p.R453Q), c.1229T>G (p.L410R) and c.1231G>T (p.G411C) in a Chinese CAH patient due to classic 11β-OHD.
With an estimated prevalence of 1 in 100 000 births, 11β-hydroxylase deficiency is the second most common form of congenital adrenal hyperplasia (CAH) and is caused by mutations in CYP11B1 Clinical features include virilization, early gonadotropin-independent precocious puberty, hypertension, and reduced stature.
In summary, CAH due to steroid 11β-hydroxylase deficiency can be attributed to both the novel deletion mutation (g.9525_9526delCT, corresponding to p.L380V…R420X) and known missense mutation (g.5194G>C corresponding to p.D63H) in CYP11B1.
We performed molecular genetic analysis of the CYP11B1 gene in six patients with preliminary clinical diagnosis of 11β-OHD and four patients identified as potential 11β-OHD from a CAH cohort in which CYP21A2 gene mutations consecutively screened.
Divergent gender identity was observed in three severely masculinized 46XX siblings with CAH who carried the same CYP11B1 mutation and had comparable postnatal and probably prenatal androgen exposure and environmental circumstances.
This is the first patient with CAH due to 11beta-OHD in Croatia (and Slavic population in general) in whom molecular diagnosis of CYP11B1 gene was performed.
It is further hypothesized that MC2R blockade should allow using lower glucocorticoid doses to treat congenital adrenal hyperplasia (CAH) due to enzyme deficiency of either 21-hydroxylase (CYP21B) or 11-hydroxylase (CYP11B1), thus reaching a better final adult height than with current therapeutic strategies.
Herein, we describe two novel CYP11B1 mutations (g659_660dupTG, p.M92X; g.4817G>A, p.R453Q) found in a patient diagnosed with classic 11OHD, after presenting with borderline elevated 17-hydroxyprogesterone concentrations in CAH newborn screening.
To define the molecular basis of steroid 11 beta-hydroxylase-deficient CAH, we cloned and sequenced the CYP11B1 gene (encoding 11 beta-hydroxylase) of a female patient afflicted with this disorder.