CYP17A1 gene mutations and hypertension variations found in 46, XY females with combined 17α-hydroxylase/17, 20-lyase deficiency

Estrogen-secreting testicular tumors in 46,XY female patients with 17α-hydroxylase/17,20-lyase deficiency: two unusual case reports and a review of the literature

Context

17α-hydroxylase/17,20-lyase deficiency (17OHD) is a rare autosomal recessive condition. Women who have the complete form of 17OHD typically have a female phenotype, with an absence of secondary sexual characteristics, primary amenorrhea, and hypertension, which is usually detected in adolescence. Generally, 46,XY patients with a partial form of 17OHD have atypical genitalia and intra-abdominal or inguinal testes. The risk of developing malignant testicular tumors or testicular adrenal rest tumors in 21-hydroxylase deficiency congenital adrenal hyperplasia is reported in 46,XY patients. In contrast, these conditions are rarely described in patients with 17OHD.

Objective

This study aims to investigate patients with 17OHD who exhibit testicular tumors and spontaneous pubertal development.

Patients and Results

Two unrelated women with 46,XY karyotype with 17OHD who presented with unexpected spontaneous development of secondary sexual characteristics and testicular tumors were described. Pathogenic allelic variants in CYP17A1 were identified in the compound heterozygous state in both patients. The variants p.Trp406Arg and p.Pro428Leu were identified in the patient with Leydig cell neoplasia plus germ cell neoplasia in situ, and the p.Arg358Gln and p.Trp406Arg variants were identified in the patient with intratubular seminoma associated with invasive classic seminoma.

Conclusion

Our findings reinforce the risk of testicular tumor development among 46,XY patients with 17OHD and add data to the discussion of the risk/benefit ratio of prophylactic gonadectomy in the treatment patients with 46, XY differences in sex development (DSD).

Novel compound heterozygous CYP17A1 mutations identified in a family with two siblings affected by 17α-hydroxylase/17,20-lyase deficiency

BACKGROUND

17α-Hydroxylase/17,20-lyase deficiency (17OHD) is a rare form of congenital adrenal hyperplasia (CAH), caused by mutations in the CYP17A1 gene. It typically manifests clinically as variable degree of hypertension, hypokalemia, and disorders of sexual development (DSD), which can include abnormal sexual differentiation in males and sexual infantilism in females. Over 100 mutations in CYP17A1 have been identified, with most cases involving missense mutations or small deletions.

METHOD

This study examined the clinical features, biochemical profiles, and genetic background of two 46, XY siblings from the same family, both diagnosed with 17OHD-a scenario that is uncommonly seen in clinical practice. We performed a genetic analysis of the CYP17A1 gene in two generations of the family to confirm the diagnosis.

RESULTS

Both patients are phenotypically female, presenting with hypertension, hypokalemia, primary amenorrhea, and absent secondary sexual characteristics. Genetic analysis revealed two novel compound heterozygous mutations in the CYP17A1 gene: R45WfsTer5 (a frameshift mutation) and L361P (a missense mutation). Neither variant is reported in the ClinVar database, and the frameshift mutation (R45WfsTer5) is newly identified.

CONCLUSIONS

The discovery of these two novel CYP17A1 mutations expands the genetic spectrum of 17OHD and provides new insights into the genetic underpinnings of the disease. Personalized treatment plans are necessary, and the choice of glucocorticoids with stronger sodium retention effects may be required to manage hypertension and electrolyte imbalances in select patients.

A rare cause of delayed puberty and primary amenorrhea: 17α-hydroxylase enzyme deficiency

AIM

17α-hydroxylase enzyme deficiency is a rare form of congenital adrenal hyperplasia (CAH) and is caused by mutations in the CYP17A1 gene. The main clinical findings are delayed puberty and primary amenorrhea in girls, and disorders of sex development in boys. It can also cause hypertension and hypokalemia in both genders. In this study, we aimed to present the clinical, laboratory and genetic results of 13 patients from eight different families who were diagnosed with complete 17α-hydroxylase enzyme deficiency.

METHODS

The age, symptoms, anthropometric measurements, blood pressure, Tanner stages, and hormonal and chromosome analysis results at the time of admission were recorded from the medical records of the patients. Whole gene next-generation sequencing of CYP17A1 gene was performed to detect mutations. Multiplex ligation dependent probe amplification (MLPA) method were used to detect deletions in the seven patients who had no point mutation were detected in the CYP17A1 gene.

RESULTS

The average age of the patients at the time of admission was 14.8 (range: 12.9-16.6) years. Also at this time, all patients were in adolescence and were raised as females. The karyotypes of eight patients were 46,XY, and of five patients were 46,XX. Ten patients presented with delayed puberty and primary amenorrhea, one patient with delayed puberty and hypertension, and two patients with hypertension and/or hypokalemia. Hypertension and hypokalemia were detected in nine and seven patients, respectively.

CONCLUSIONS

P450c17 enzyme deficiency should be considered in patients presenting with delayed puberty or primary amenorrhea in the adolescence period and diagnosed with hypergonadotropic hypogonadism, if hypertension and hypokalemia accompany. Early diagnosis prevents the occurrence of important health problems such as hypertension, psychological problems, and gender identity disorders, which affect the majority of these patients.

Genetic screening for monogenic hypertension in hypertensive individuals in a clinical setting

BACKGROUND

Monogenic hypertension describe a series of hypertensive syndromes that are inherited by Mendelian laws. Sometimes genetic testing is required to provide evidence for their diagnoses, precise classification and targeted treatment. This study is the first to investigate the clinical utility of a causative gene screening and the combined yield of gene product expression analyses in cases with suspected monogenic hypertension.

METHODS

We performed a large-scale multi-centre clinical genetic research of 1179 expertly selected hypertensive individuals from the Chinese Han population. Targeted sequencing were performed to evaluate 37 causative genes of potential cases of monogenic hypertension. Pathogenic and likely pathogenic variants were classified using the American College of Medical Genetics guidelines. Additionally, 49 variants of unknown significance (VUS) that had relatively high pathogenicity were selected and analysed using immunoblot protein expression assays.

RESULTS

21 pathogenic or likely pathogenic variants were identified in 33 of 1179 cases (2.80%). Gene product expression analyses showed 27 VUSs harboured by 49 individuals (4.16%) could lead to abnormally expressed protein levels. Consequently, combining genetic screening with gene product expression analyses increased the diagnostic yield from 2.80% to 6.79%. The main aetiologies established were primary aldosteronism (PA; 27, 2.29%) and pheochromocytoma and paraganglioma (PPGL; 10, 0.85%).

CONCLUSION

Molecular diagnoses obtained using causative gene screening combined with gene product expression analyses initially achieved a modest diagnostic yield. Our data highlight the predominant roles of PA and PPGL. Furthermore, we provide evidence indicating the enhanced diagnostic ability of combined genetic and functional evaluation.

A report of congenital adrenal hyperplasia due to 17α-hydroxylase deficiency in two 46,XX sisters

Congenital adrenal hyperplasia (CAH) is a group of rare orphan disorders caused by mutations in seven different enzymes that impair cortisol biosynthesis. The 17α-hydroxylase deficiency (17OHD) is one of the less common forms of CAH, corresponding to approximately 1% of the cases, with an estimated annual incidence of 1 in 50,000 newborns. Cases description - two phenotypically female Ecuadorian sisters, both with primary amenorrhea, absence of secondary sexual characteristics, and osteoporosis. High blood pressure was present in the older sister. Hypergonadotropic hypogonadism profile was observed: decreased cortisol and dehydroepiandrosterone sulfate (DHEAS), increased adrenocorticotropic hormone (ACTH) and normal levels of 17-hydroxyprogesterone, extremely high deoxycorticosterone (DOC) levels, and a tomography showed bilateral adrenal hyperplasia in both sisters. Consanguinity was evident in their ancestors. Furthermore, in the exon 7, the variant c.1216T > C, p.Trp406Arg was detected in homozygosis in the CYP17A1 gene of both sisters. We report a homozygous missense mutation in the CYP17A1 gene causing 17OHD in two sisters from Loja, Ecuador. According to the authors, this is the first time such deficiency and mutation are described in two members of the same family in Ecuador.

A Rare Cause of Congenital Adrenal Hyperplasia: Clinical and Genetic Findings and Follow-up Characteristics of Six Patients with 17-Hydroxylase Deficiency Including Two Novel Mutations

OBJECTIVE

17α-hydroxylase/17,20 lyase deficiency (17OHD) is a rare form of congenital adrenal hyperplasia (CAH), characterized by hypertension and varying degrees of ambiguous genitalia and delayed puberty. The disease is associated with bi-allelic mutations in the CYP17A1 gene located on chromosome 10q24.3. We aimed to present clinical and genetic findings and follow-up and treatment outcomes of 17OHD patients.

METHODS

We evaluated six patients with 17OHD from five families at presentation and at follow up. Standard deviation score of all auxological measurements was calculated according to national data and karyotype status. CYP17A1 gene sequence alterations were investigated in all patients.

RESULTS

The mean (±standard deviation) age of patients at presentation and follow-up time was 14.6±4.2 and 5.0±2.7 years respectively. Five patients were referred to us because of delayed puberty and primary amenorrhea and four for hypertension. One novel single nucleotide insertion leading to frame shift and another novel variant occurring at an ultra rare position, leading to a missense change, are reported, both of which caused 17OHD deficiency. Steroid replacement was started. The three patients with 46,XY karyotype who were raised as females underwent gonadectomy. Osteoporosis was detected in five patients. Four patients needed antihypertensive treatment. Improvement in osteoporosis was noted with gonadal steroid replacement and supportive therapy.

CONCLUSION

17OHD, a rare cause of CAH, should be kept in mind in patients with pubertal delay and/or hypertension. Patients with 46,XY who are raised as females require gonadectomy. Due to late diagnosis, psychological problems, gender selection, hypertension and osteoporosis are important health problems affecting a high proportion of these patients.

17α-HYDROXYLASE/17, 20-LYASE DEFICIENCY: CLINICAL AND MOLECULAR CHARACTERIZATION OF EIGHT CHINESE PATIENTS

OBJECTIVE

17α-hydroxylase/17, 20-lyase deficiency (17OHD) is caused by mutations in the cytochrome P450 17A1 (CYP17A1) gene. To better understand 17OHD, a rare disease, we described the clinical features and performed CYP17A1 gene analysis in 8 affected Chinese patients.

METHODS

Patients with complete (7/8) or partial (1/8) 17OHD were derived from 6 families. The diagnosis was established according to their clinical, biochemical, hormonal, and radiological characteristics. Long-term follow-up of some patients was also designed.

RESULTS

Patients with 17OHD suffered from varying degrees of hypokalemia and hypertension. Symptoms in female patients with partial 17OHD manifested as secondary amenorrhea, recurrent ovarian cysts, elevated estradiol level, and lower follicle-stimulating hormone and luteinizing hormone levels; primary amenorrhea was typical in patients with complete 17OHD. Adrenal masses and decreased bone mineral density (BMD) were discovered in 2 patients, respectively. During long-term follow-up, 4 patients developed low BMD, while 3 individuals underwent respiratory infections and recurrent urinary tract infections. CYP17A1 gene analysis revealed 7 different kinds of mutation, including 1 novel mutation, L266V.

CONCLUSION

The clinical characteristics of partial 17OHD were different from those of complete 17OHD. Low BMD and infections were common in patients with 17OHD on long-term steroid treatment. Seven mutations were identified in the CYP17A1 gene, and 1 was novel.

ABBREVIATIONS

ACTH = adrenocorticotropic hormone BMD = bone mineral density CAH = congenital adrenal hyperplasia CT = computed tomography DEXA = dual-energy X-ray absorptiometry DEX = dexamethasone 17OHD = 17α-hydroxylase/17, 20-lyase deficiency.