Partial deficiency of 17α-hydroxylase: a rare cause of congenital adrenal hyperplasia

Clinicoradiologic diagnosis of a rare type of congenital adrenal hyperplasia: A case report from Nepal

Congenital adrenal hyperplasia includes defects in the synthesis of steroid hormones in the adrenal cortex. The implications of this disorder manifest in other genitourinary organs, including ovaries and uterus. The diagnosis may be suspected based on the clinical and radiologic features.

Reproductive endocrine characteristics and in vitro fertilization treatment of female patients with partial 17α-hydroxylase deficiency: Two pedigree investigations and a literature review

BACKGROUND

17α-hydroxylase/17, 20-lyase deficiency (17-OHD) is caused by the mutations of the CYP17A1 gene. The classical phenotype of 17-OHD includes hypertension, hypokalemia, and abnormal sexual development, with partial 17-OHD typically less severe than the complete deficiency. Infertility is always one of the main clinical manifestations of partial 17-OHD. However, to date, the pregnancy potentials of partial 17-OHD female patients have rarely been investigated, and few live-birth cases have been reported among them. Moreover, the reproductive endocrine characteristics of partial 17-OHD female patients have not been completely clarified and the treatment skills of in vitro fertilization and embryo transfer (IVF-ET) have not been well summarized yet.

METHODS

Two Chinese infertile female patients clinically diagnosed as partial 17-OHD were enrolled and their pedigree investigations were performed. Hormones were determined to depict the endocrine conditions of partial 17-OHD female patients. The adrenocorticotropic hormone (ACTH) stimulation test was performed to evaluate the functions of the adrenal cortex. Genotype analysis was conducted by next-generation sequencing (NGS) and Sanger sequencing was used to verify the results. IVF-ET was performed for the treatment of their infertility. Specifically, the progestin-primed ovarian stimulation (PPOS) protocol was chosen for the controlled ovarian hyperstimulation (COH) cycles, and the hormone replacement treatment (HRT) protocol was adopted for the endometrial preparation in frozen-thawed embryo transfer (FET) cycles.

RESULTS

Hormone assays revealed a reduced estradiol (E2) and testosterone (T) level, and an elevated progesterone (P4) level. The classic ACTH stimulating test evidenced a suboptimal response of cortisol to ACTH. Genotype analysis demonstrated that the proband1 carried two variants: c.1459_1467del (p.Asp487_Phe489del)^het and c.995T>C (p.lle332Thr)^het. The proband2 was found to be a homozygote with the mutation of c.1358T>A (p.Phe453Ser)^hom. The two female patients both succeeded in pregnancy and delivery of healthy babies through IVF-ET, with the usage of PPOS, HRT, and low-dose glucocorticoids.

CONCLUSIONS

Partial 17-OHD female patients manifested menstrual cycle disorders and infertility clinically; displayed high P4 and low E2 and T; showed sparse pubic hair in physical examinations; and revealed multiple ovarian cysts in ultrasonic visualization. Moreover, the pregnancy potentials of infertile partial 17-OHD women seemed to increase with the adoption of IVF-ET. Considering the sustained elevated P4 level, PPOS is a feasible protocol for them in COH.

Clinical characteristics and molecular etiology of partial 17α-hydroxylase deficiency diagnosed in 46,XX patients

INTRODUCTION

Complete 17α-hydroxylase deficiency (17OHD) is relatively common, with typical juvenile female genitalia, severe hypertension, hypokalemia, and the absence of sexual development, but partial (or non-classical) 17OHD (p17OHD) is extremely rare. The p17OHD patients can present with a broad spectrum of symptoms in 46,XX karyotype including various degree of spontaneous breast development after puberty, recurrent ovarian cysts, oligomenorrhea and infertility depending on specific gene mutations and other influencing factors.

METHODS

This paper is a retrospective analysis of p17OHD cases from 1997 to 2021 in a Chinese tertiary hospital. Eight patients were recruited from unrelated families according to clinical data. Genotypes of patients were determined by sequencing the CYP17A1 genes. Clinical characteristics were summarized based on manifestations, hormone profiles, and responses to treatments.

RESULTS

All seven post-pubertal patients had abnormal menses. All patients had enlarged multilocular ovaries, and six (6/8) had a history of ovarian cystectomy prior to a definite diagnosis of p17OHD. All eight patients' sex hormone levels were in accord to hypogonadism with mildly elevated follicle-stimulating hormone levels, and oral contraceptives effectively suppressed the ovarian cysts. Of the four patients who underwent plasma renin activity tests, all showed results below the reference range. Fourteen alleles with a CYP17A1 mutation were found. Exon 6 was the most frequent mutation site (5/14), and four out of these five mutations were c.985_987delTACinsAA, being the most common one. In Case 2, c.1220dupA was a newly reported mutation of CYP17A1.

CONCLUSIONS

46,XX p17OHD patients were born with highly fragile ovarian reserve due to diverse mutations of CYP17A1. However, their multi-ovarian cysts can be managed conservatively for fertility preservation. This study focuses on p17OHD in 46,XX by locating the complex genetic causes in novel mutations, summarizing the puzzling spectrum of clinical manifestations, and illustrating the significance of fertility preservation in these scarce cases.

Nonclassic Congenital Adrenal Hyperplasia: What Do Endocrinologists Need to Know?

Congenital adrenal hyperplasia encompasses a group of autosomal recessive defects in cortisol biosynthesis, and 21-hydroxylase deficiency accounts for 95% of such cases. Non-classic 21-hydroxylase deficiency is due to partial enzymatic defects, which present with normal cortisol synthesis, but excessive production of adrenal androgens, including 11-oxygenated androgens. Non-classic 21-hydroxylase deficiency is relatively common, and its phenotype resembles closely that of polycystic ovary syndrome. This review focuses primarily on non-classic 21-hydroxylase deficiency, its clinical features, diagnosis, and management.

Overview of Monogenic Forms of Hypertension Combined With Hypokalemia

Hypertension is an important risk factor in many conditions and creates a heavy burden of disease and mortality globally. Polygenic hypertension is the most common form; however, it is increasingly recognized that monogenic hypertension is not rare, especially in patients with electrolyte disorders. Single genetic alterations are associated with plasma volume expansion and catecholamines/sympathetic excess with simultaneously increased potassium excretion in the urine and potassium intracellular shift. Early-onset refractory hypertension and profound hypokalemia are characteristics of monogenic hypertension. However, accumulated evidence shows the existence of phenotypic heterogeneity in monogenic hypertension meaning that, even for mild symptoms, clinicians cannot easily exclude the possibility of monogenic hypertension. Genetic, epigenetic and non-genetic factors are all possible mechanisms influencing phenotypic diversity. Genetic sequencing is a precise and efficient method that can broaden the mutant gene spectrum of the disease and is very helpful for understanding the pathophysiology of monogenic hypertension. Genetic sequencing, along with biochemical tests and imaging modalities, is essential for the early diagnosis and targeted management of monogenic hypertension to avoid long-term catastrophic complications.