A high rate of novel CYP11B1 mutations in Saudi Arabia

The clinical characteristics and quality of life of 248 pediatric and adult patients with Congenital Adrenal Hyperplasia

Background

Congenital Adrenal Hyperplasia (CAH) is a chronic disease that requires lifelong treatment. Patients may face stigmatization, which may affect their quality of life (QoL). Therefore, we assessed the clinical characteristics and QoL of patients with CAH in the Middle East.

Methods

This case-control study included patients with CAH aged >5 years from two tertiary centers (2020-2021). The patients were matched to a healthy control group and were then divided into pediatric and adult groups. Data were collected from their electronic medical records. Additionally, the EQ-5D-5L QoL questionnaire was completed by both the patients and control group to assess five domains (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression).

Results

The study included 248 patients with CAH (females: 58.8%), with a family history of the condition (57.3%) and/or parental consanguinity (68.1%). The most frequently reported gene defect was CYP21A2, while the most commonly reported symptoms/signs were ambiguous genitalia and obesity. Almost all female patients had received corrective surgery. The questionnaire response rate was 86.3% (n=214/248). The CAH patient group's mean total QoL score was 85.2 compared with 99.8 in the control. Further, CAH patients had lower QoL scores in all domains compared to those in the control group (p ≤ 0.0001-0.0023). The pain/discomfort and anxiety/depression domains were affected significantly more than the other domains were, with 47.7% and 44.4% participants, respectively, p<0.0001. Additionally, obesity was found to be a predictor of reduced mobility following a logistic regression analysis (p ≤ 0.04, OR (0.18-0.98)).

Conclusion

Patients with CAH reported lower QoL overall, particularly in the pain/discomfort and anxiety/depression domains. Based on this, we recommend the early involvement of psychologists in a multidisciplinary team approach, pre-marital screening, and the implementation of awareness programs for people diagnosed with CAH in communities with high consanguineous mating.

Congenital adrenal hyperplasia caused by compound heterozygosity of two novel CYP11B1 gene variants

BACKGROUND

Congenital adrenal hyperplasia (CAH) is an autosomal recessive disorder caused by pathogenic variants in seven genes involved in the cortisol and aldosterone biosynthetic pathway. The second most common cause, 11β-hydroxylase deficiency (11βOHD), is attributed to pathogenic variants in the CYP11B1 gene encoding for the enzyme 11β-hydroxylase (11βOH).

CASE PRESENTATION

A 13-year-old girl was referred to the pediatric endocrinologist due to a syncopal episode. She is the third child of non-consanguineous parents. She presented with premature adrenarche at the age of 6 years and menarche at the age of 12 years. On physical examination, her height was 154.5 cm and weight 50 kg, while she presented with acne, hirsutism, clitoromegaly, and normal blood pressure. Laboratory investigation revealed increased androgen levels and poor cortisol response to the ACTH stimulation test. From the family history, the mother was diagnosed with CAH at the age of 10 years and was under treatment with methylprednisolone. Previous molecular investigation of the CYP21A2 gene was negative. Due to the increased androstenedione levels in the index patient, the suspicion of 11βOH was raised, and she was investigated for 11-deoxycortisol, 11-deoxycorticosterone, and CYP11B1 gene pathogenic variants. The patient and her mother were found to be compound heterozygous for two novel variants of the CYP11B1 gene.

CONCLUSION

We present a case of CAH due to compound heterozygosity of two novel pathogenic variants of the CYP11B1 gene, emphasizing the importance of molecular investigation in order to confirm clinical diagnosis and allow proper genetic counseling of the family.

Molecular genetics of disorders of sex development in a highly consanguineous population

Consanguinity increases the risk of hereditary diseases including disorders of sex development (DSD). There are minimal data on DSD in the highly consanguineous population of Saudi Arabia. This study reports the molecular genetics of a series of patients with different types of DSD.

METHODS

We enrolled 77 patients from 47 families with DSD. DNA was isolated from peripheral leucocytes. Genes of interest were amplified by polymerase chain reaction and subsequently sequenced.

RESULTS

Overall, 77 patients from 47 families (44 of them are consanguineous) had a total of 29 mutations; 16 of them were described before and 13 were novel mutations. The most common condition was 5-α reductase (SRD5A2) deficiency (25 patients from 18 families) and the most common mutation was a splice site mutation in intron 1 (c.282-2A>G). The next most common condition was 11-β hydroxylase (CYP11B1) deficiency where 19 patients from 10 families had 8 mutations (7 of them are novel). Other mutations affected CYP17A1 with 2 novel and 2 known mutations in 7 patients; HSD3B2 with 2 known mutations in 11 patients of 4 families; StAR with 1 novel and 1 known mutations in 4 patients; NR0B1 with 1 novel mutation in 2 siblings; HSD17B3 with 1 known mutation in 3 siblings; LHCGR with 1 novel mutation in 2 siblings; and AR with 1 novel and 3 known mutations in 4 unrelated patients.

CONCLUSION

In the highly consanguineous and homogeneous population of Saudi Arabia, SRD5A2 and CYP11B1 deficiencies are common causes of DSDs. Other DSDs occur less frequently but often with novel mutations.

Non-classical 11β-hydroxylase deficiency caused by compound heterozygous mutations: a case study and literature review

BACKGROUND

11β-hydroxylase deficiency (11OHD) is extremely rare, and reports of non-classical 11OHD are even rarer. Non-classical 11OHD usually presents as premature adrenarche, hyperandrogenism, menstrual disorders, and hypertension. Because the symptoms of non-classical 11OHD are mild, delayed diagnosis or misdiagnosis as polycystic ovary syndrome or primary hypertension is common.

CASE PRESENTATION

This paper introduces a case of a young female patient presenting hypertension and menstrual disorders. Laboratory examination revealed increased androgen levels, mild adrenal hyperplasia, mild left ventricular hypertrophy, and mild sclerosis of the lower limb arteries. 11OHD was confirmed by genetic testing, and the patient was found to carry compound heterozygous mutations in CYP11B1 (c.583 T > C and c.1358G > A). The mutation Y195H is located in exon 3 and has not been reported previously. In silico studies indicated that this mutation may cause reduced enzymatic activity. After treatment with hydrocortisone and spironolactone, blood pressure was brought under good control, and menstruation returned to normal. We also conducted a retrospective review of previously reported cases in the literature (over 170 cases since 1991).

CONCLUSIONS

Early diagnosis of non-classical 11OHD is difficult because its symptoms are mild. The possibility of this disease should be considered in patients with early-onset hypertension, menstrual disorders, and hyperandrogenism to provide early treatment and prevent organ damage due to hypertension and hyperandrogenism. CYP11B1 mutations are known to be race-specific and are concentrated in exons 3 and 8, of which mutations in the former are mostly associated with non-classical 11OHD, whereas mutations in the latter are mostly found in classical 11OHD, characterized by severe loss of enzymatic activity.