P450c17 deficiency in Brazilian patients: biochemical diagnosis through progesterone levels confirmed by CYP17 genotyping

A Case Report of 17α-Hydroxylase Deficiency in Two Saudi Siblings With Different Karyotyping

Congenital adrenal hyperplasia (CAH) consists of variable disorders of sex determination and differentiation. 17α-hydroxylase deficiency (17OHD) is an uncommon form of those disorders, which is typically characterized by hypertension, hypokalemia, failure of puberty, and ambiguous genitalia. The 17α-hydroxylase enzyme is encoded by the CYP17A1 gene and it is required for the synthesis of cortisol and sex steroids. The affected females with 17OHD usually present with primary amenorrhea and delayed puberty, which are associated with hypertension and hypokalemia while male patients might show female external genitalia, pseudohermaphroditism, or variable degrees of ambiguous genitalia with intra-abdominal testes in addition to hypertension and hypokalemia as well. We present two Saudi siblings (19 and 16 years old) who were diagnosed with the rare CAH subtype of 17OHD after presenting with long-standing hypertension, refractory hypokalemia, and failure of puberty. It is interesting that both siblings had biochemical primary adrenal insufficiency; however, both patients did not clinically present with an acute adrenal crisis, which is likely due to the effect of increased levels of deoxycorticosterone. Additionally, although both patients have similar phenotypes and clinical presentations, they have different karyotypes. This again highlights the variability of the manifestations that can result from 17OHD even with an identical mutation in the same family. Both patients were treated successfully with dexamethasone, which has led to the normalization of hypertension, resolution of hypokalemia, and discontinuation of anti-hypertensive medications and potassium supplements after several years of treatment. However, the entire management is quite challenging and requires a multidisciplinary approach regarding difficult issues such as gender identity and assignment and fertility issues in addition to a life-long follow-up.

Focus on adrenal and related causes of hypertension in childhood and adolescence: Rare or rarely recognized?

High blood pressure (BP) is not restricted to adults; children and adolescents may also be affected, albeit less frequently. Aside from unfavorable environmental factors, such as obesity and sedentary life leading to early-onset essential hypertension (HT), several secondary causes must be investigated in the occasional hypertensive child/adolescent. Endocrine causes are relevant and multiple, related to the pituitary, thyroid, parathyroid, gonads, insulin, and others, but generally are associated with adrenal disease. This common scenario has several vital components, such as aldosterone, deoxycorticosterone (DOC), cortisol, or catecholamines, but there are also monogenic disorders involving the kidney tubule that cause inappropriate salt retention and HT that simulate adrenal disease. Finally, a blood vessel disease was recently described that may also participate in this vast spectrum of pediatric hypertensive disease. This review will shed some light on the diagnosis and management of conditions, focusing on the most prevalent adrenal (or adrenal-like) disturbances causing HT.

Monogenic forms of low-renin hypertension: clinical and molecular insights

Monogenic disorders of hypertension are a distinct group of diseases causing dysregulation of the renin-angiotensin-aldosterone system and are characterized by low plasma renin activity. These can chiefly be classified as causing (i) excessive aldosterone synthesis (familial hyperaldosteronism), (ii) dysregulated adrenal steroid metabolism and action (apparent mineralocorticoid excess, congenital adrenal hyperplasia, activating mineralocorticoid receptor mutation, primary glucocorticoid resistance), and (iii) hyperactivity of sodium and chloride transporters in the distal tubule (Liddle syndrome and pseudohypoaldosteronism type 2). The final common pathway is plasma volume expansion and catecholamine/sympathetic excess that causes urinary potassium wasting; hypokalemia and early-onset refractory hypertension are characteristic. However, several single gene defects may show phenotypic heterogeneity, presenting with mild hypertension with normal electrolytes. Evaluation is based on careful attention to family history, physical examination, and measurement of blood levels of potassium, renin, and aldosterone. Genetic sequencing is essential for precise diagnosis and individualized therapy. Early recognition and specific management improves prognosis and prevents long-term sequelae of severe hypertension.

Phenotypic Heterogeneity and Fertility Potential of Patients With 17-Hydroxylase/17,20-lyase Deficiency

CONTEXT

17α-Hydroxylase/17,20-lyase deficiency (17OHD) is caused by a human CYP17A1 gene mutation and has the classical phenotype of hypertension, hypokalemia, sexual infantilism, and primary amenorrhea in females (46,XX) and disorders of sexual development in males (46,XY). To date, few cases of 17OHD have been reported, and the likelihood of pregnancy has rarely been explored.

OBJECTIVE

To study the clinical characteristics, phenotype heterogeneity, genotyping, and the likelihood of pregnancy of patients with 17OHD.

DESIGN

Genotype analysis was performed by direct sequencing of the CYP17A1 gene and next-generation sequencing in nonclassical patients. In vitro enzyme activity assays and 3-dimensional structure observations were used to assess the function of 3 missense mutations of the CYP17A1 gene. Progestin-primed ovarian stimulation (PPOS) was chosen for ovulation induction in 2 patients.

RESULTS

Eight mutations were identified from 13 patients, including the homozygous mutations p. N395D and p. R496C and compound heterozygous mutations p. Y329fs/p. A421A and p. I332T/p. D487_F489del in 4 nonclassical patients. For the 3 missense mutations, an in vitro functional study showed mild impairment of 17α-hydroxylase activities 15.3-25.0% but residual 17,20-lyase activities 6.6%-9.4%. Two 46,XX females succeeded in pregnancy and delivery by combined PPOS, in vitro fertilization embryo transfer (IVF-ET), and the use of low-dose glucocorticoids.

CONCLUSIONS

Partial 17OHD present nonclassical clinical features, without hypertension and hypokalemia. Successful pregnancy in such 46,XX patients could be attained by the appropriate choice of ovulation induction regimen, precise dose of glucocorticoid to reduce progesterone levels, and the use of IVF-ET.

Contribution of Clinical and Genetic Approaches for Diagnosing 209 Index Cases With 46,XY Differences of Sex Development

CONTEXT

Massively parallel sequencing (MPS) technologies have emerged as a first-tier approach for diagnosing several pediatric genetic syndromes. However, MPS has not been systematically integrated into the diagnostic workflow along with clinical/biochemical data for diagnosing 46,XY differences of sex development (DSD).

OBJECTIVE

To analyze the contribution of phenotypic classification either alone or in association with genetic evaluations, mainly MPS, for diagnosing a large cohort of 46,XY DSD patients.

DESIGN/PATIENTS

209 nonsyndromic 46,XY DSD index cases from a Brazilian DSD center were included. Patients were initially classified into 3 subgroups according to clinical and biochemical data: gonadal dysgenesis (GD), disorders of androgen secretion/action, and DSD of unknown etiology. Molecular genetic studies were performed by Sanger sequencing and/or MPS.

RESULTS

Clinical/biochemical classification into either GD or disorders of hormone secretion/action was obtained in 68.4% of the index cases. Among these, a molecular diagnosis was obtained in 36% and 96.5%, respectively. For the remainder 31.6% classified as DSD of clinically unknown etiology, a molecular diagnosis was achieved in 31.8%. Overall, the molecular diagnosis was achieved in 59.3% of the cohort. The combination of clinical/biochemical and molecular approaches diagnosed 78.9% of the patients. Clinical/biochemical classification matched with the genetic diagnosis in all except 1 case. DHX37 and NR5A1 variants were the most frequent genetic causes among patients with GD and DSD of clinical unknown etiology, respectively.

CONCLUSIONS

The combination of clinical/biochemical with genetic approaches significantly improved the diagnosis of 46,XY DSD. MPS potentially decreases the complexity of the diagnostic workup as a first-line approach for diagnosing 46,XY DSD.

17α-hydroxylase/17,20-lyase deficiency in 46, XY: our experience and review of literature

Context

There are more than 100 pathogenic variants in CYP17A1 that have been identified in patients with 17α-hydroxylase/17,20-lyase deficiency (17OHD).

Objective

We aimed to describe 46,XY patients with 17OHD from our center and review the literature.

Methods

We retrospectively analyzed genetically proven index cases of 17OHD from our 46,XY disorders of sex development cohort and reviewed similar cases from the literature (n = 150). Based on the phenotype, 17OHD probands were classified into combined severe deficiency (n = 128) and combined partial deficiency (n = 16). Additionally, patients with the apparent isolated 17,20-lyase deficiency (n = 7, from 6 families) were noted. Residual enzyme activities with the observed mutant enzymes were divided in 2 categories as < 1% and ≥ 1%, each for hydroxylase and lyase.

Results

We present 4 index cases of 46,XY 17OHD with a complete spectrum of undervirilization and 2 novel variants in CYP17A1. In the review, the combined severe deficiency was the most common form, with more frequent female sex of rearing, hypertension, hypokalemia, suppressed renin, higher plasma corticotropin, lower serum cortisol, and androgens. Immunoassay-measured serum aldosterone was frequently (68.2%) unsuppressed (>5 ng/dL). Elevated serum progesterone had high sensitivity for diagnosis of combined 17OHD, even in combined partial deficiency (83.3%). Among patients with clinical phenotype of combined severe deficiency, 11.5% had partial 17α-hydroxylase and complete 17,20-lyase deficiency (>1%/<1%) and had significantly higher serum cortisol than those with < 1%/<1% activity.

Conclusion

We report the first monocentric case series of Asian Indian 46,XY patients with 17OHD. We propose that a phenotype of severe undervirilization with milder cortisol deficiency may represent a distinct subtype of combined severe 17OHD with residual 17α-hydroxylase activity but severe 17,20-lyase deficiency (>1%/<1%), which needs further validation.

An Asian case of combined 17α-hydroxylase/17,20-lyase deficiency due to homozygous p.R96Q mutation: A case report and review of the literature

BACKGROUND

Combined 17α-hydroxylase/17,20-lyase deficiency (17-OHD) is a very rare form of congenital adrenal hyperplasia (CAH) caused by mutations in the CYP17A1 gene. Almost 100 different mutations of the CYP17A1 gene have been reported, including p.R96Q mutation, but no case of p.R96Q mutation has been described in Asian populations.

CASE PRESENTATION

We describe a 22-year-old female patient of 46,XY karyotype, who presented with pseudohermaphrodism, primary amenorrhea, underdeveloped secondary sexual characteristics, delayed epiphyseal healing, hypertension, and hypokalemia. The diagnosis of 17-OHD was reached by measurement of steroid hormones and abdominal CT scan and confirmed by genetic sequencing, which revealed a homozygous p.R96Q missense mutation in the CYP17A1 gene. The patient received treatment with dexamethasone and estradiol, and 4 months of follow-up showed that both blood pressure and potassium were well controlled.

CONCLUSIONS

This is the first Asian case of CAH caused by a homozygous p.R96Q missense mutation in the CYP17A1 gene. Herein, we highlight the role of inguinal hernia in the early diagnosis of female 17-OHD and the necessity of removing the ectopic testis.

Dexamethasone application for in vitro fertilisation in non-classic 17-hydroxylase/17,20-lyase-deficient women

CONTEXT

High progesterone levels in the follicular stage interfere with the implantation window, causing infertility in women with 17-hydroxylase/17,20-lyase deficiency (17OHD). Dexamethasone can restore cortisol deficiency and suppress inappropriate mineralocorticoid secretion to control hypertension in 17OHD patients, but poses risks to the foetus if administered during pregnancy.

OBJECTIVE

We prospectively explored a rational glucocorticoid use protocol for assistive reproduction in a woman with non-classic 17OHD that reduced glucocorticoid side effects.

METHOD

In this study, the treatment protocol for this 17OHD patient included the following steps. First, the appropriate type and dose of glucocorticoid for endogenous progesterone suppression was determined. Then, glucocorticoid was discontinued to increase endogenous progesterone levels for ovarian stimulation. Next, dexamethasone plus GnRHa were used to reduce progesterone levels in frozen embryos for transfer. Once pregnancy was confirmed, dexamethasone was discontinued until delivery.

RESULTS

Dexamethasone, but not hydrocortisone, reduced progesterone levels in the 17OHD woman. After endogenous progesterone-primed ovarian stimulation, 11 oocytes were retrieved. Seven oocytes were 2PN fertilised and four day-3 and two day-5 embryos were cryopreserved. After administering dexamethasone plus gonadotropin-releasing hormone agonist (GnRHa) to reduce progesterone levels to normal, hormone replacement therapy was administered until the endometrial width reached 9 mm. Exogenous progesterone (60 mg/day) was used for endometrial preparation. Two thawed embryos were transferred on day 4. Dexamethasone was continued until pregnancy confirmation on the 13^th day post-transfer. Two healthy boys, weighing 2100 and 2000 g, were delivered at 36 weeks' gestation.

CONCLUSION

Rational use of dexamethasone synchronised embryonic development with the endometrial implantation window, while not using in post-implantation avoided its side effects and promoted healthy live births in women non-classic 17OHD undergoing in vitro fertilisation.

Novel mutations of the CYP17A1 gene in four Chinese 46,XX cases with partial 17a-hydroxylase/17,20-lyase deficiency

The condition 17a-Hydroxylase/17,20-lyase deficiency (17-OHD) is a rare kind of congenital adrenal hyperplasia (CAH) characterized by failure to synthetize cortisol, adrenal androgens and gonadal steroids. Partial deficiency is much rarer, presenting with subtler symptoms. In this study, we summarized the clinical characteristics and identified the underlying gene mutation in four Chinese 46,XX patients with partial 17-OHD. Mutational analysis of the CYP17A1 gene was performed by polymerase chain reaction (PCR) and Sanger sequencing. Clinical and hormonal findings in these patients were consistent with typical manifestations of partial 17-OHD. All patients were found to have a compound heterozygous mutation of the CYP17A1 gene, with five mutations identified. Among them, c.887 T > C(p. I296T), c.1019G > A(p. R340H) and c.1346G > A(p. R449H) were novel missense mutations. In conclusion, we identified three novel missense mutations of the CYP17A1 gene from four patients with partial 17-OHD deficiency. Genotype-phenotype correlation analysis revealed that these novel mutations can lead to partial 17-OHD. Our findings thus provide novel insight into the clinical evaluations and molecular basis of 17-OHD.

Multidisciplinary team management of 46,XY 17α-hydroxylase deficiency: a case report and literature review

BACKGROUND

We report here a case study of 17α-hydroxylase deficiency in a phenotypic girl with male karyotype (46,XY). We also review the relevant literature to deepen our understanding of the disease, reduce the rate of missed diagnosis, and emphasize that holistic management of this disease requires collaborative multidisciplinary teamwork.

CASE PRESENTATION

A 14-year-old patient with a female phenotype visited the endocrinology department because of hypertension. The patient had primary amenorrhea and lacked secondary sexual characteristics. Initial laboratory evaluation revealed normal levels of electrolytes, a hypergonadotropic hypogonadal state with high progesterone and low testosterone levels, and a 46,XY karyotype. She was referred to the urology department for gonadectomy and transferred to the gynecological endocrine clinic. On the basis of the patient's medical history and genetic testing results, a diagnosis of 46,XY 17α-hydroxylase deficiency was made. The patient was provided with glucocorticoids, estrogens, metformin, and psychological support.

CONCLUSIONS

Patients with 17α-hydroxylase deficiency, a rare cause of congenital adrenal hyperplasia, should be treated by a multidisciplinary team. Relevant experts from different disciplines should set up a systematic and comprehensive individualized management plan to optimize the physical and mental health and quality of life of affected patients.

A Novel Compound Heterozygous CYP17A1 Variant Causes 17α-Hydroxylase/17, 20-Lyase Deficiency

Background: Congenital adrenal hyperplasia (CAH) encompasses a group of autosomal recessive diseases characterized by enzyme deficiencies, within steroid hormone anabolism, which lead to disorders in cortisol synthesis. The 17α-hydroxylase/17,20-lyase deficiency (17-OHD) is an uncommon form of CAH caused by variants in the CYP17A1 gene.

Aims: We report a novel compound heterozygous CYP17A1 variant and its association with the pathogenesis of 17-OHD.

Methods: The patient was assessed for medical history, clinical manifestations, physical examination, laboratory examination, karyotype analysis, and adrenal computed tomography. Mutation screening was conducted using whole-exome sequencing (WES) and Sanger sequencing. The wild-type and mutant CYP17A1 complementary DNAs (cDNAs) were amplified and cloned into a pcDNA3.1(+) vector. These plasmids were transfected transiently into HEK-293T cells. Quantitative PCR and Western blotting analysis were performed to measure the expression level of P450c17. An enzymatic activity assay was conducted to measure the content of 17-hydroxyprogesterone (17-OHP) and dehydroepiandrosterone (DHEA) in medium using liquid chromatography–tandem mass spectrometry (LC-MS/MS).

Results: The proband was characterized by 17-OHD with rhabdomyolysis, hypokalemia, and adrenal insufficiency. Novel compound heterozygous variants of the CYP17A1 gene (c.1304T > C/p.Phe435Ser and c.1228delG/p.Asp410Ilefs*9) were identified. The enzymatic activity assay revealed that this variant resulted in a complete deficiency of 17α-hydroxylase and 17,20-lyase activity. This was consistent with the hormonal characteristics of the proband’s blood.

Conclusions: These results suggest that the compound heterozygous variant of c.1304T > C and c.1228delG of the CYP17A1 gene can lead to 17-OHD. Our findings thus provide a novel insight into the clinical evaluations and molecular basis of 17-OHD.

Prevalence of CYP17A1 gene mutations in 17α-hydroxylase deficiency in the Chinese Han population

BACKGROUND

17α-hydroxylase deficiency is a rare autosomal recessive disorder caused by mutations in the cytochrome P450 family 17 subfamily A member 1 gene. The major clinical presentation includes hypertension, hypokalemia, male pseudohermaphroditism and female gonadal dysplasia. Hundreds of pathogenic variants have been reported in this disorder, and some common mutations were found to be race-specific.

CASE PRESENTATION

In this study, we reported 5 Chinese girls with 17α-hydroxylase deficiency from Henan Province. The patients all came to the hospital for hypertension, and they also presented with sexual infantilism. The average age of the patients was 14 years old, ranging from 12 to 17 years old. They all had reduced blood cortisol, estradiol (E2), and testosterone (TESTO) and increased adrenocorticotropic hormone (ACTH), follicle-stimulating hormone (FSH), and luteinizing hormone (LH). They all had the appearance of females; however, three of the chromosome karyotypes were 46XX, and two were 46XY.

CONCLUSIONS

All of the patients carried a mutation on the 329 amino acid of CYP17A1 exon 6. By summarizing the currently known pathogenic mutations of 17α-hydroxylase deficiency, we demonstrated the prevalence of these gene mutations in Chinese Han and non-Chinese populations.

Evaluation and management of amenorrhea related to congenital sex hormonal disorders

Primary amenorrhea is a symptom with a substantial list of underlying etiologies which presents in adolescence, although some conditions are diagnosed in childhood. Primary amenorrhea is defined as not having menarche until 15 years of age (or 13 years with secondary sex characteristics). Various etiologies of primary amenorrhea include outflow tract obstructions, gonadal dysgenesis, abnormalities of the central nervous system, various endocrine diseases, chronic illnesses, psychologic problems, and constitutional delay of puberty. The management of primary amenorrhea may vary considerably depending on the patient and the specific diagnosis. In this article, the various causes, evaluation, and management of primary amenorrhea are reviewed with special emphasis on congenital sex hormonal disorders.

The CYP17A1 gene polymorphisms are associated with hypercholesterolemia in Han Chinese

BACKGROUND

The CYP17A1 gene has been identified to associate with hypertension in Chinese population. However, the association between CYP17A1 polymorphisms and hypertension-related factors is unclear. The present study aimed to investigate the relation between CYP17A1 single nucleotide polymorphisms (SNPs) and serum lipid profiles.

METHODS

In total, 1350 participants were included in the study. Six SNPs in or near CYP17A1 gene were genotyped in a Han Chinese population in two stages.

RESULTS

There was a statistically significant association of rs1004467 (adjusted odds ratio = 0.783, 95% confidence interval = 0.667-0.919, p < 0.05) and rs11191548 (adjusted odds ratio = 0.788, 95% confidence interval = 0.672-0.925, p < 0.05) with hypercholesterolemia after adjustment for potential factors. Additionally, the rs1004467 minor G-allele and the rs11191548 minor C-allele were significantly associated with the lower serum total cholesterol levels (p < 0.05 for all).

CONCLUSIONS

The rs1004467 and rs11191548 in the CYP17A1 gene are associated with a decreased risk of hypercholesterolemia and lower serum TC levels in Han Chinese.

Mutations in PIK3C2A cause syndromic short stature, skeletal abnormalities, and cataracts associated with ciliary dysfunction

PIK3C2A is a class II member of the phosphoinositide 3-kinase (PI3K) family that catalyzes the phosphorylation of phosphatidylinositol (PI) into PI(3)P and the phosphorylation of PI(4)P into PI(3,4)P2. At the cellular level, PIK3C2A is critical for the formation of cilia and for receptor mediated endocytosis, among other biological functions. We identified homozygous loss-of-function mutations in PIK3C2A in children from three independent consanguineous families with short stature, coarse facial features, cataracts with secondary glaucoma, multiple skeletal abnormalities, neurological manifestations, among other findings. Cellular studies of patient-derived fibroblasts found that they lacked PIK3C2A protein, had impaired cilia formation and function, and demonstrated reduced proliferative capacity. Collectively, the genetic and molecular data implicate mutations in PIK3C2A in a new Mendelian disorder of PI metabolism, thereby shedding light on the critical role of a class II PI3K in growth, vision, skeletal formation and neurological development. In particular, the considerable phenotypic overlap, yet distinct features, between this syndrome and Lowe’s syndrome, which is caused by mutations in the PI-5-phosphatase OCRL, highlight the key role of PI metabolizing enzymes in specific developmental processes and demonstrate the unique non-redundant functions of each enzyme. This discovery expands what is known about disorders of PI metabolism and helps unravel the role of PIK3C2A and class II PI3Ks in health and disease.

Identifying the genetic basis of rare disorders can provide insight into gene function, susceptibility to disease, guide the development of new therapeutics, improve opportunities for genetic counseling, and help clinicians evaluate and potentially treat complicated clinical presentations. However, it is estimated that the genetic basis of approximately one-half of all rare genetic disorders remains unknown. We describe one such rare disorder based on genetic and clinical evaluations of individuals from 3 unrelated consanguineous families with a similar constellation of features including short stature, coarse facial features, cataracts with secondary glaucoma, multiple skeletal abnormalities, neurological manifestations including stroke, among other findings. We discovered that these features were due to deficiency of the PIK3C2A enzyme. PIK3C2A is a class II member of the phosphoinositide 3-kinase (PI3K) family that catalyzes the phosphorylation of the lipids phosphatidylinositol (PI) into PI(3)P and the phosphorylation of PI(4)P into PI(3,4)P2 that are essential for a variety of cellular processes including cilia formation and vesicle trafficking. This syndrome is the first monogenic disorder caused by mutations in a class II PI3K family member and thus sheds new light on their role in human development.

Three new Brazilian cases of 17α-hydroxylase deficiency: clinical, molecular, hormonal, and treatment features

BACKGROUND

Deficiency of 17α-hydroxylase (17OHD) is a rare form of adrenal hyperplasia. Diagnosis is generally delayed, impairing appropriate treatment.

CASE PRESENTATION

Here, we report the clinical, molecular, hormonal, and treatment data of three unrelated 17OHD patients, aged 14-16 years with hypergonadotrophic hypogonadism; uncontrolled hypertension; primary adrenal insufficiency; and high progesterone, low to normal potassium, and low dehydroepiandrosterone, androstenedione, and testosterone levels. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) at baseline and after an adrenocorticotropic hormone test showed low cortisol and cortisone and high deoxycorticosterone (DOC) and corticosterone levels; both DOC/21-deoxycortisol and costicosterone/cortisol ratios were very high. Patient 2 had 46,XX karyotype and patients 1 and 3, had 46,XY. A molecular analysis showed that two of the patients were homozygous for p.W406R mutation and the other patient was compound heterozygous for p.W406R and p.P428L. Hypertension was controlled only after the administration of both prednisone and mineralocorticoid antagonist.

CONCLUSIONS

Hypertension in young women must lead to diagnostic suspicion, even in the pre-pubertal period. The basal level of progesterone is an indicator of 17OHD. Mineral and glucocorticoid ratios obtained from LC-MS/MS can reinforce the diagnosis. Hypertension can be controlled using glucocorticoid replacement therapy and mineralocorticoid antagonist.

Phase I Study of Seviteronel, a Selective CYP17 Lyase and Androgen Receptor Inhibitor, in Men with Castration-Resistant Prostate Cancer

Purpose: Seviteronel (INO-464) is a selective cytochrome P450c17a (CYP17) 17,20-lyase (lyase) and androgen receptor (AR) inhibitor with antitumor activity in vitro and in vivo This open-label phase I clinical study evaluated the safety, tolerability, pharmacokinetics and activity of once-daily seviteronel in male chemotherapy-naïve subjects with castration-resistant prostate cancer (CRPC).Patients and Methods: Seviteronel was administered at 600 mg once daily with dose titration (DT) and in modified 3 + 3 dose escalation once-daily cohorts at 600, 750, and 900 mg without DT. The primary objectives of this study were to establish safety, tolerability, and the MTD of seviteronel in chemotherapy-naïve subjects with or without prior treatment with FDA-approved CRPC treatments, abiraterone acetate (AA), and enzalutamide. Secondary objectives were to assess pharmacokinetics, PSA, tumor response, and endocrine results.Results: Twenty-one subjects were enrolled. No dose-limiting toxicities (DLT) were observed through 750 mg once daily. Most treatment-emergent adverse events (AE) reported at grade 1-2. The most commonly reported AEs were fatigue (71%), dizziness (52%), blurred vision (38%), and dysgeusia (33%), with most AEs improving after dose reduction or dose interruption.Conclusions: Once-daily seviteronel was generally well tolerated in this phase I study of men with CRPC, a majority of which had progressed on prior AA or enzalutamide, or both. Of the doses evaluated, 600 mg once daily was chosen as the recommended phase II dose for future studies in subjects with CRPC. Clin Cancer Res; 24(21); 5225-32. ©2018 AACR.

Phase 1 study of seviteronel, a selective CYP17 lyase and androgen receptor inhibitor, in women with estrogen receptor-positive or triple-negative breast cancer

PURPOSE

Seviteronel (INO-464) is an oral, selective cytochrome P450c17a (CYP17) 17,20-lyase (lyase) and androgen receptor inhibitor with in vitro and in vivo anti-tumor activity. This open-label phase 1 clinical study evaluated safety, tolerability, pharmacokinetics (PK), and activity of once-daily (QD) seviteronel in women with locally advanced or metastatic TNBC or ER+ breast cancer.

METHODS

Seviteronel was administered in de-escalating 750, 600, and 450 mg QD 6-subject cohorts. The 750 mg QD start dose was a phase 2 dose determined for men with castration-resistant prostate cancer in (Shore et al. J Clin Oncol 34, 2016). Enrollment at lower doses was initiated in the presence of dose-limiting toxicities (DLTs). The primary objective of this study was to determine seviteronel safety, tolerability, and MTD. The secondary objectives included description of its PK in women and its initial activity, including clinical benefit rate at 4 (CBR16) and 6 months (CBR24).

RESULTS

Nineteen women were enrolled. A majority of adverse events (AEs) were Grade (Gr) 1/2, independent of relationship; the most common were tremor (42%), nausea (42%), vomiting (37%), and fatigue (37%). Four Gr 3/4 AEs (anemia, delirium, mental status change, and confusional state) deemed possibly related to seviteronel occurred in four subjects. DLTs were observed at 750 mg (Gr 3 confusional state with paranoia) and 600 mg (Gr 3 mental status change and Gr 3 delirium) QD, with none at 450 mg QD. The recommended phase 2 dose (RP2D) was 450 mg QD, and at the RP2D, 4 of 7 subjects reached at least CBR16 (2 TNBC subjects and 2 ER+ subjects achieved CBR16 and CBR24, respectively); no objective tumor responses were reported.

CONCLUSIONS

Once-daily seviteronel was generally well tolerated in women with and 450 mg QD was chosen as the RP2D.

Common variant rs11191548 near the CYP17A1 gene is associated with hypertension and the serum 25(OH) D levels in Han Chinese

The CYP17A1 gene, which encodes17α-hydroxylase and 17,20-lyase, has been identified as a common hypertension susceptibility locus in a European population. However, the association between CYP17A1 polymorphisms and hypertension is unclear in the Chinese population as well as in the role of serum 25(OH) D levels. Six single nucleotide polymorphisms (SNPs) in CYP17A1 were genotyped in two stages in a Han Chinese population, and the serum 25(OH) D levels were measured. Analysis in stage 1 showed that the rs1004467 minor G-allele and rs11191548 minor C-allele in CYP17A1 were significantly associated with a decreased risk of hypertension and higher serum 25(OH) D levels (all P < 0.05). The larger sample in stage 2 also showed that a mutation in rs11191548 was significantly associated with a decreased risk of hypertension (adjusted OR = 0.707, 95% CI: 0.553-0.904, P = 0.006). The rs11191548 minor C-allele was associated with higher serum 25(OH) D levels in hypertensive subjects (βadj ± SEM = 0.094 ± 0.949, P = 0.003) and controls (βadj ± SEM = 0.128 ± 1.025, P < 0.001). In conclusion, the rs11191548 CYP17A1 gene mutation was associated with hypertension and the serum 25(OH) D levels in Han Chinese.

17α-HYDROXYLASE DEFICIENCY IS AN UNDERDIAGNOSED DISEASE: HIGH FREQUENCY OF MISDIAGNOSES IN A LARGE COHORT OF BRAZILIAN PATIENTS

OBJECTIVE

17α-Hydroxylase deficiency (P450c17D) is characterized by hypogonadism and mineralocorticoid hypertension. We aimed to estimate the relative incidence and spectrum of preliminary misdiagnoses in Brazilian P450c17D patients.

METHODS

In this cross-sectional study, we reviewed, updated, and analyzed data of 40 P450c17D patients (21 XY, 19 XX).

RESULTS

Complete data were unavailable for 2 patients. Seven patients were relatives of an index case. Of the 31 index cases, 29 (94%) received a total of 16 misdiagnoses (1-4 per patient) before confirmation of P450c17D. Essential hypertension (55%), pure gonadal dysgenesis (35%), and androgen resistance syndrome (21%) were the most frequent misdiagnoses. Median ages at initial and final diagnosis were 13.2 and 16.5 years, respectively, with an average interval to diagnosis of 3.2 years. Initially, 38 (95%) patients had hypertension, and 75% had hypokalemia. Primary amenorrhea and sexual infantilism were present in 95% patients, and 73% were at Tanner stage I. All had low-to-undetectable estrogens and androgens with elevated gonadotropins and progesterone (580 ± 53 ng/dL). Several had recurrent infections in childhood and neurological issues prior to final diagnosis and/or had siblings who died of infectious diseases or unknown causes before puberty.

CONCLUSION

The high percentage of prior misdiagnoses in P450c17D patients may be attributable to the rarity of and relative unfamiliarity with the disease, its varied clinical presentation, and the limited access to critical steroid dosages and genotyping. Reduced sex steroids, and elevated gonadotropins and progesterone levels, in addition to mineralocorticoid hypertension, are pathognomonic of P450c17D. CYP17A1 gene mutations provide a definitive diagnosis.

ABBREVIATIONS

ACTH = adrenocorticotropic hormone CAH = congenital adrenal hyperplasia CYP17A1 = 17α-hydroxylase enzyme DOC = deoxycorticosterone HH = hypergonadotropic hypogonadism P450c17D = 17α-hydroxylase deficiency TS = Tanner stage.

Delayed Diagnosis of a 17-Hydroxylase/17,20-Lyase Deficient Patient Presenting as a 46,XY Female: A Low Normal Potassium Level Can Be an Alerting Diagnostic Sign

17-hydroxylase/17,20-lyase deficiency (17-OHD), a rare autosomal recessive defect in adrenal and gonadal steroidogenesis, causes absence of secondary sexual characteristics and frequently associated with hypertension and hypokalemia. Here, we report a 46,XY case who had normal potassium levels and no hypertension. Our patient was a 2.5-year-old female admitted with female external genitalia and inguinal swelling. Pathology of biopsy revealed that this gonad was a testis. Karyotype was 46,XY. She had no hypertension and no hypokalemia. Serum luteinizing hormone and follicle-stimulating hormone levels were high; testosterone, dehydroepiandrosterone sulfate, and androstenedione were low. Human chorionic gonadotrophin stimulation resulted in partial testosterone response. She was initially diagnosed as partial gonadal dysgenesis or testosterone synthesis defect. In her follow-up after noticing low normal potassium levels at age 9 years, progesterone level was measured and detected to be high. Adrenocorticotropic hormone-stimulated steroid measurements were consistent with 17-OHD. Genetic analyses revealed p. R96Q (c.287G>A) homozygous mutation on exon 1 of CYP17A1 gene. In conclusion, evaluation of 46,XY disorder of sex development patients must include serum potassium levels, and near low levels of potassium levels should also suggest 17-OHD despite absence of hypertension or remarkable hypokalemia. Testosterone synthesis defects must be excluded before establishing the diagnosis of partial gonadal dysgenesis.

Female phenotype with male karyotype: a clinical enigma

Development of gonadal and phenotypic sex during embryogenesis invariably corresponds to the genotypic sex. However, some disorders of sex development are associated with discordance between the chromosomal, gonadal or phenotypic sex which include complete androgen insensitivity syndrome, 46XY complete gonadal dysgenesis (Swyer syndrome) and, rarely, congenital adrenal hyperplasia due to CYP 17A1 (17α-hydroxylase) deficiency. The enzyme CYP17A1 includes 17α-hydroxylase and 17,20-lyase which are required for the synthesis of cortisol and sex steroids, respectively. The consequent cortisol deficiency results in a compensatory increase in adrenocorticotropic hormone (ACTH) drive, which stimulates the production of deoxycorticosterone and corticosterone leading to hypertension and hypokalaemia. Concurrent lack of sex steroids results in sexual infantilism without ambiguity. Both the genotypic males and females present during adolescence with a female phenotype, sexual infantilism and hypertension depending on the severity of the enzyme deficiency. We describe a case of CYP17A1 deficiency in a phenotypic female with 46XY karyotype who presented with sexual infantilism but without hypertension.

Steroid 17-hydroxylase and 17,20-lyase deficiencies, genetic and pharmacologic

Steroid 17-hydroxylase 17,20-lyase (cytochrome P450c17, P450 17A1, CYP17A1) catalyzes two major reactions: steroid 17-hydroxylation followed by the 17,20-lyase reactions. The most severe mutations in the cognate CYP17A1 gene abrogate all activities and cause combined 17-hydroxylase/17,20-lyase deficiency (17OHD), a biochemical phenotype that is replicated by treatment with the potent CYP17A1 inhibitor abiraterone acetate. The adrenals of patients with 17OHD synthesize 11-deoxycorticosterone (DOC) and corticosterone but no 19-carbon steroids, similar to the rodent adrenal, and DOC causes hypertension and hypokalemia. Loss of 17,20-lyase activity precludes sex steroid synthesis and leads to sexual infantilism. Rare missense CYP17A1 mutations minimally disrupt 17-hydroxylase activity but cause isolated 17,20-lyase deficiency (ILD), Mutations in the POR gene encoding the required cofactor protein cytochrome P450-oxidoreductase causes a spectrum of disease from ILD to 17OHD combined with 21-hydroxylase and aromatase deficiencies, sometimes including skeletal malformations. Mutations in the CYB5A gene encoding a second cofactor protein cytochrome b₅ also selectively disrupt 17,20-lyase activity and cause the purest form of ILD. The clinical manifestations of these conditions are best understood in the context of the biochemistry of CYP17A1.

Clinical and molecular manifestation of fifteen 17OHD patients: a novel mutation and a founder effect

17-hydroxylase deficiency (17OHD) has long been regarded as a rare form of congenital adrenal hyperplasia, inherited in an autosomal recessive pattern. Fifteen patients with 17OHD were described from clinical manifestations and hormone profile. Then, CYP17A1 gene was amplified and sequenced in a new patient. Heterozygous mutations c. 431_433del, p.K144del/c. 985_987delinsAA, p.Y329 fs were identified. Functional study indicated the novel mutation K144del completely abolished enzyme activity. In the three-dimensional model, the K144del mutation completely destroyed the alpha helix in the steroid binding domain. Sixteen SNPs within CYP17A1 gene were selected and genotyped in 7 unrelated families to determine whether Y329 fs had founder effect in China. Haplotyping study showed that all c. 985_987delinsAA mutation shared the same haplotype. However, from GWAS data of 2760 controls, this special haplotype was found only in one chromosome. In conclusion, we identified a novel (K144del) and a widely reported (Y329 fs) heterozygous mutations of CYP17A1 gene from a 17OHD patient. Haplotyping analysis showed the common mutation Y329 fs in China came from the same ancestor, which explains the reason that 17OHD was the second cause of CAH in China.

Disorders of sex development: effect of molecular diagnostics

Disorders of sex development (DSDs) are a diverse group of conditions that can be challenging to diagnose accurately using standard phenotypic and biochemical approaches. Obtaining a specific diagnosis can be important for identifying potentially life-threatening associated disorders, as well as providing information to guide parents in deciding on the most appropriate management for their child. Within the past 5 years, advances in molecular methodologies have helped to identify several novel causes of DSDs; molecular tests to aid diagnosis and genetic counselling have now been adopted into clinical practice. Occasionally, genetic profiling of embryos prior to implantation as an adjunct to assisted reproduction, prenatal diagnosis of at-risk pregnancies and confirmatory testing of positive results found during newborn biochemical screening are performed. Of the available genetic tests, the candidate gene approach is the most popular. New high-throughput DNA analysis could enable a genetic diagnosis to be made when the aetiology is unknown or many differential diagnoses are possible. Nonetheless, concerns exist about the use of genetic tests. For instance, a diagnosis is not always possible even using new molecular approaches (which can be worrying for the parents) and incidental information obtained during the test might cause anxiety. Careful selection of the genetic test indicated for each condition remains important for good clinical practice. The purpose of this Review is to describe advances in molecular biological techniques for diagnosing DSDs.

New, recurrent, and prevalent mutations: Clinical and molecular characterization of 26 Chinese patients with 17alpha-hydroxylase/17,20-lyase deficiency

BACKGROUND

Combined 17alpha-hydroxylase/17,20-lyase deficiency (17OHD), caused by mutations in the CYP17A1 gene, is a rare autosomal recessive form of congenital adrenal hyperplasia and characterized by hyporeninemic hypokalemic hypertension, primary amenorrhea and absence of secondary sexual characteristics.

SUBJECTS AND METHODS

Twenty six 17OHD subjects from 23 Chinese families were recruited. The CYP17A1 gene was sequenced and 17alpha-hydroxylase/17,20-lyase enzymatic activities were assessed in vitro.

RESULTS

Eight CYP17A1 mutations were identified in 23 patients. Of eight mutations, c.985_987delinsAA/p.Y329Kfs and c.1460_1469del/p.D487_F489del mutations accounted for 60.8% (28/46) and 21.7% (10/46) of the mutant alleles, respectively. The enzymatic activities for both mutations were completely abolished. We also identified three novel mutations c.971_972insG/p.K325Afx, c.1464_1466delT/p.F489Sfx and c.1386G>T/p.R462S. The enzymatic activities for c.971_972insG/p.K325Afx and c.1464_1466delT/p.F489Sfx mutations were almost completely abolished, whereas the mutation c.1386G>T/p.R462S only resulted in partial reduction of 17alpha-hydroxylase (34.6%) and 17,20 lyase activities (27.0%), which is correlated with the partial 17OHD phenotype in this patient.

CONCLUSION

The c.985_987delinsAA/p.Y329Kfs and c.1460_1469del/p.D487_F489del mutations are prevalent in Chinese 17OHD patients. The genetic defects are well correlated with the phenotypes in both complete and partial forms of 17OHD.

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

The aim of this study was to analyze the structural consequences of the mutations in CYP17A1 gene and their relationship with the variations of clinical manifestations in three patients who presented with complete or partial combined 17α-hydroxylase/17,20-lyase deficiency (17OHD). DNA sequences of the coding exons and intron/exon boundaries of the CYP17A1 gene were analyzed for mutations. In silico analysis with computational three-dimensional model of human P450c17 and multiple alignments analysis were performed to evaluate the spatial conformational changes by missense mutations. Five mutations p.S117fs (c.351_352delCT), p.H373L (c.1184 A>T), p.Y329fs (c.985_987delTACinsAA), p.A82D (c.245 C>A) and p.L209P (c.626 T>C) were identified in three patients, respectively. The novel mutation p.S117fs (c.351_352delCT) has not been reported previously. In silico analysis explained the conformational changes by the described mutations, which resulted in different severe 17OHD. Our studies also suggest that molecular data accompanying with in silico analysis of the CYP17A1 gene are much helpful for the diagnosis, management and genetic counseling of 17OHD.

Immunoexpression of aromatase cytochrome P450 and 17β-hydroxysteroid dehydrogenase in women's ovaries after menopause

Background

Menopause results in a lack of regular menstrual cycles, leading to the reduction of estrogen production. On the other hand, ovarian androgen synthesis is still present at reduced levels and requires expression of several steroidogenic enzymes.

Methods

This study was performed on 104 postmenopausal women hospitalized due to uterine leiomyomas, endometriosis, and/or a prolapsed uterus. Patients were divided into three groups depending on the time from menopause. Group A patients experienced menopause 1–5 years before enrollment in the study (42 women). Group B included women who had their last menstruation 5–10 years before the study (40 women). Group C consisted of 22 women who were more than 10 years past menopause. Hysterectomy or removal of the uterine corpus with adnexa was performed during laparotomy. We evaluated the expression of aromatase cytochrome P450 (CYP 19) and 17β-hydroxysteroid dehydrogenase (17β HSD) by employing immunohistochemistry.

Results

Activity of 17β-HSD and CYP19 was demonstrated in the cytoplasm of stromal cells of postmenopausal ovaries, epithelium cells coating the ovaries, vascular endothelial cells, and epithelial inclusion cysts. However, overall expression of both 17β-HSD and CYP 19 decreased with time after menopause.

Conclusion

Demonstration of the activity of the key enzymes of ovarian steroidogenesis, CYP 19 and 17β-HSD, confirms steroidogenic activity in the ovaries of postmenopausal women. Nevertheless, ovarian steroidogenic activity decreases with time, and its significant decrease occurs 10 years after menopause.

A review of the literature on common CYP17A1 mutations in adults with 17-hydroxylase/17,20-lyase deficiency, a case series of such mutations among Koreans and functional characteristics of a novel mutation

OBJECTIVE

17α-hydroxylase/17,20-lyase deficiency is a rare form of congenital adrenal hyperplasia, characterized by hypertension and sexual infantilism and caused by loss-of-function mutations in CYP17A1. This study investigated the clinical and molecular characteristics of six adults with 17α-hydroxylase/17,20-lyase deficiency and the functional consequences of a novel CYP17A1 mutation.

MATERIALS AND METHODS

Six phenotypic females, three with 46,XY and three with 46,XX karyotypes, presented with primary amenorrhea and hypertension. All had elevated levels of plasma adrenocorticotropic hormone, serum gonadotropin, progesterone, and 11-deoxycorticosterone, and reduced testosterone and dehydroepiandrosterone sulfate (DHEA-S). All coding exons and flanking intronic sequences of CYP17A1 were directly sequenced using genomic DNA. Wild-type and mutant CYP17A1 cDNAs were inserted into the pcDNA3.1/V5-His-P450c17 vector, and transiently expressed in COS-7 cells. This was followed by an assessment of 17α-hydroxylase and 17,20-lyase activities by measuring the conversions of progesterone to 17-hydroxyprogesterone and 17-hydroxypregnenolone to DHEA.

RESULTS

The mutation analysis identified one patient with compound heterozygosity for p.H373L and p.W406L, one with compound heterozygosity for p.H373L and p.A174E, three with compound heterozygosity for p.Y329fs and p.H373L, and one with homozygosity for p.H373L. An in vitro functional analysis of the novel p.W406L mutation revealed a complete loss of 17α-hydroxylase/17, 20-lyase activities.

CONCLUSIONS

p.H373L was the most common mutation among these Korean patients, consistent with the high allele frequency of p.H373L in Chinese and Japanese populations, suggesting possible founder effects in Asian countries. The novel p.W406L mutation caused a complete loss of both catalytic activities, indicating that this amino acid is critical for P450c17 function.

Common polymorphism rs11191548 near the CYP17A1 gene is associated with hypertension and systolic blood pressure in the Han Chinese population

Background The single-nucleotide polymorphism (SNP) rs11191548, near the CYP17A1 gene, has been identified as being associated with hypertension and systolic blood pressure (SBP) in genome-wide association studies (GWAS) in a European population. The CYP17A1 gene encodes cytochrome P450c17alpha and plays an important role in the steroidogenic pathway, which includes mineralocorticoids. Methods We investigated the SNP rs11191548 in a case-control study of 1,102 subjects with essential hypertension (EH) and 1,109 normotensive controls. Results The SNP rs11191548 was significantly associated with hypertension in an additive genetic model (genotypes CC vs. TC vs. TT; odds ratio (OR) = 1.27 (95% CI, 1.10-1.47; P = 0.001)). The ORs of the TC vs. TT and CC vs. TT genotypes were 1.34 (95% CI, 1.10-1.63; P = 0.003) and 1.52 (95% CI, 1.10-2.12; P = 0.014), respectively. The risk C-allele was associated with increased SBP (βadj ± SEM = 1.307±0.515; P = 0.011) levels in the controls and decreased plasma renin activity (PRA) (βadj ± SEM = -0.053±0.016; P = 0.001) in the subjects with EH. In a stratified analysis of renin-angiotensin-aldosterone-system (RAAS)-related antagonists, the C-allele was significantly associated with decreased serum potassium (K(+)) (βadj ± SEM = -0.093±0.028; P = 0.001) and PRA (βadj ± SEM = -0.067±0.023; P = 0.003) levels in patients with EH who were not taking RAAS-related antagonists. These results remained statistically significant after correction for multiple corrections. Conclusions The SNP rs11191548, near the CYP17A1 gene, was associated with hypertension and SBP in a Chinese Han population. The rs11191548 polymorphism was also related to lower PRA and K(+) levels, suggesting that it has an effect on the enzymatic activity of CYP17A1.

Recapitulation of four hypertension susceptibility genes (CSK, CYP17A1, MTHFR, and FGF5) in East Asians

OBJECTIVE

A recent genome wide association study identified eight hypertension susceptibility loci in Europeans. Subsequently, several studies have investigated these associations in East Asian populations. The results of these studies, however, have been inconsistent. A meta-analysis was performed to assess the associations of the most published polymorphisms, including CSK rs1378942, CYP17A1 rs11191548, MTHFR rs17367504, and FGF5 rs16998073 polymorphisms with hypertension.

METHODS

Published literature from PubMed and Embase databases was retrieved. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using fixed- or random-effects model.

RESULTS

Seven studies (16,368 cases /19,707 controls) for CSK rs1378942 polymorphism, seven studies (15,688 cases /18,784 controls) for CYP17A1 rs11191548 polymorphism, four studies (7994 cases / 12,844 controls) for MTHFR rs17367504 polymorphism, and three studies (6026 cases / 8393 controls) for FGF5 rs16998073 polymorphism were included in the meta-analysis. The results suggested that both CYP17A1 rs11191548 and FGF5 rs16998073 polymorphisms were significantly associated with hypertension risk in East Asians (CYP17A1 rs11191548 (random effect model): OR=1.16, 95% CI 1.07-1.25, p=3.59×10(-4), I(2)=78.2%, p (heterogeneity)=1.14×10(-4); FGF5 rs16998073 (random effect model): OR=1.30, 95% CI 1.23-1.37, p=6.29×10(-21), I(2)=65.0%, p (heterogeneity)=0.009); whereas no significant association was observed for CSK rs1378942 (fix effect model: OR=1.09, 95% CI 0.98-1.22, p=0.128, I(2)=0.0%, p (heterogeneity)=0.820), or MTHFR rs17367504 (fix effect model: OR=1.06, 95% CI 0.98-1.14, p=0.126, I(2)=0.0%, p (heterogeneity)=0.822).

CONCLUSION

The present meta-analysis indicated significant associations of both CYP17A1 rs11191548 and FGF5 rs16998073 polymorphisms with hypertension susceptibility in East Asians.

CYP17A1 mutations identified in 17 Chinese patients with 17α-hydroxylase/17,20-lyase deficiency

CONTEXT

17α-hydroxylase deficiency (17OHD) is a relatively rare disease, accounting for about 1% of congenital adrenal hyperplasia cases. The CYP17A1 gene mutation can lead to this disease. Human CYP17A1 gene is located on chromosome 10q24.3. It consists of eight exons encoding 508 amino acids. To date, more than 50 mutations in exons and introns of the CYP17A1 gene have been reported to cause complete or partial 17OHD.

OBJECTIVE

The aim of this study was to investigate the CYP17A1 gene mutation types in 17 Chinese patients, containing 11 complete and six partial 17OHD patients.

SETTING

We conducted the study in the Department of Obstetrics and Gynecology of Peking Union Medical College Hospital.

PATIENTS

Seventeen patients were studied with complete or partial 17OHD.

MAIN OUTCOME MEASURES

The CYP17A1 gene was sequenced and we measured steroid and sex hormone levels.

RESULTS

Analysis of the CYP17A1 gene in our patients revealed 12 different kinds of mutation. Two mutations (IVS1-1G>A and L209P) were novel mutations. Mutation c.985_987delTACinsAA (Y329KfsX418) in Exon 6 was the most common mutation in Chinese patients, accounting for 50 percents of the mutant alleles (17/34). Exon 6 was the hot spot since most mutations were detected in this exon (59%, 20/34 alleles). There was no mutation detected in the Exons 4 and 5.

Orthostatic hypotension and novel blood pressure-associated gene variants: Genetics of Postural Hemodynamics (GPH) Consortium

Aims

Orthostatic hypotension (OH), an independent predictor of mortality and cardiovascular events, strongly correlates with hypertension. Recent genome-wide studies have identified new loci influencing blood pressure (BP) in populations, but their impact on OH remains unknown.

Methods and results

A total of 38 970 men and women of European ancestry from five population-based cohorts were included, of whom 2656 (6.8%) met the diagnostic criteria for OH (systolic/diastolic BP drop ≥20/10 mmHg within 3 min of standing). Thirty-one recently discovered BP-associated single nucleotide polymorphisms (SNPs) were examined using an additive genetic model and the major allele as referent. Relations between OH, orthostatic systolic BP response, and genetic variants were assessed by inverse variance-weighted meta-analysis. We found Bonferroni adjusted (P < 0.0016) significant evidence for association between OH and the EBF1 locus (rs11953630, per-minor-allele odds ratio, 95% confidence interval: 0.90, 0.85–0.96; P = 0.001), and nominal evidence (P < 0.05) for CYP17A1 (rs11191548: 0.85, 0.75–0.95; P = 0.005), and NPR3-C5orf23 (rs1173771: 0.92, 0.87–0.98; P= 0.009) loci. Among subjects not taking BP-lowering drugs, three SNPs within the NPPA/NPPB locus were nominally associated with increased risk of OH (rs17367504: 1.13, 1.02–1.24; P = 0.02, rs198358: 1.10, 1.01–1.20; P = 0.04, and rs5068: 1.22, 1.04–1.43; P = 0.01). Moreover, an ADM variant was nominally associated with continuous orthostatic systolic BP response in the adjusted model (P= 0.04).

Conclusion

The overall association between common gene variants in BP loci and OH was generally weak and the direction of effect inconsistent with resting BP findings. These results suggest that OH and resting BP share few genetic components.

Molecular study of five Chinese patients with 46XX partial 17a-hydroxylase/17,20-lyase deficiency

CONTEXT

Partial 17a-hydroxylase/17,20 lyase deficiency (17OHD) is a rare subtype of 17OHD caused by CYP17 gene mutations.

OBJECTIVE

Five Chinese 46,XX patients and one family with partial 17OHD were genotyped.

PATIENTS

The five patients derived from different families and one of them had another patient in family. The diagnosis of partial 17OHD was established through clinical and laboratory characteristics in Peking Union Medical College Hospital, China, from 2000 to 2010.

RESULTS

Seven CYP17 gene mutations are identified from these patients. Among them, R449C and L209P are two novel missense mutations. Four patients are found to have a compound heterozygous mutations and one patient has only one mutation. The patients with family history are also found to have parent origin of gene mutations.

CONCLUSION

Two novel missense mutations in CYP1 7 are found in this study. Comparing with previous reports, the different combination of mutations may have various effects on the activities of the 17-hydroxylase and/or17,20-lyase.

Three novel CYP17A1 gene mutations (A82D, R125X, and C442R) found in combined 17α-hydroxylase/17,20-lyase deficiency

The aim of this study was to analyze the structure and functional consequences of 3 novel mutations (A82D, R125X, and C442R) of the CYP17A1 gene found in 2 patients with combined 17α-hydroxylase/17,20-lyase deficiency (17OHD). Two Chinese 46, XY female patients were diagnosed with 17OHD based on clinical findings and biochemical results. The CYP17A1 gene was analyzed by polymerase chain reaction direct sequencing. An in vitro expression system was performed in HEK293 cells to analyze the mutant P450c17 activity compared with the wild type. Analysis of the CYP17A1 gene sequences in patient 1 showed compound heterozygous mutations A82D (g.417 C > A) in exon 1 and Y329fs (g.4869 T > A, 4871del) in exon 6; DNA sequencing analysis in patient 2 revealed compound heterozygous mutations R125X (g.2045 C > T) in exon 2 and C442R (g.6457 T > C) in exon 8. The mutations A82D, R125X, and C442R have not been reported previously. The functional study demonstrated that the A82D, R125X, and C442R mutations almost completely eliminate enzymatic activity. These results, which indicate that Ala 82 and Cys 442 are crucial for both 17-hydroxylase and 17,20-lyase activities, help define the structure-function relationship of the CYP17A1 gene. The novel mutations A82D, R125X, and C442R further clarify the patients' clinical manifestations of combined 17OHD.

Distinctive profile of the 17-hydroxylase and 17,20-lyase activities revealed by urinary steroid metabolomes of patients with CYP17 deficiency

OBJECTIVES

(1) Characterize serum (S) and urinary (U) steroid metabolites in complete CYP17 deficiency (cCYP17D); (2) analyze the relative 17α-hydroxylase (17OH) and 17,20-lyase (17,20L) activities in vivo; and (3) comparedata from the two most prevalent mutations in Brazil.

SUBJECTS AND METHODS

20 genotyped cCYP17D patients from a previously reported cohort were homozygous for W406R or R362C; 11 controls were CYP17 wild types (WT). WT and cCYP17D patients had S and U samples drawn to measure: cortisol (F), corticosterone (B), deoxycorticosterone (DOC), 18OH-B, 18OH-DOC, and 17OHP; and tetrahydro (TH)-B, THA, THDOC, THF+5α-THF, TH-cortisone, androsterone, etiocholanolone, 5-pregnenediol, 17OH-pregnenolone and pregnanetriol.

RESULTS

Compared to WT, cCYP17D patients had marked elevations of B, DOC, 18OH-B and 18OH-DOC, whereas 17OHP, F and adrenal androgens (AA) were reduced; U steroids parallel S findings. Metabolite ratios revealed that both 17OH and 17,20L activities were impaired in cCYP17D. There were nodifferences between W406R andR362C mutations.

CONCLUSIONS

cCYP17D patients show parallel overproduction/overexcretion of 17-deoxysteroids, and marked reduction of F and AA. In addition to 17OH, 17,20-L activity was also impaired in cCYP17D. W406 and R362C mutations disclose similar Sand U patterns.

Combined 17α-hydroxylase/17,20-lyase deficiency due to p.R96W mutation in the CYP17 gene in a Brazilian patient

Congenital adrenal hyperplasia (CAH) resulting from 17α-hydroxylase/17,20-lyase deficiency is a rare autosomal recessive disease and the second most common form of CAH in Brazil. We describe the case of a Brazilian patient with CYP17 deficiency (17α-hydroxylase/17,20-lyase deficiency) caused by a homozygous p.R96W mutation on exon 1 of the CYP17 gene, an unusual genotype in Brazilian patients with this form of CAH. The patient, raised as a normal female, sought medical care for lack of pubertal signs and primary amenorrhea at the age of 16 years. At evaluation, the presence of a 46,XY karyotype, hypertension and hypokalemia were observed. We emphasize the recognition of CYP17 deficiency in the differential diagnosis of cases of hypergonadotrophic hypogonadism and hypertension in young patients who need specific treatment for both situations.

Six new cases confirm the clinical molecular profile of complete combined 17α-hydroxylase/ 17,20-lyase deficiency in Brazil

In 2004, Costa-Santos and cols. reported 24 patients from 19 Brazilian families with 17α-hydroxylase deficiency and showed that p.W406R and p.R362C corresponded to 50% and 32% of CYP17A1 mutant alleles, respectively. The present report describes clinical and molecular data of six patients from three inbred Brazilian families with 17α-hydroxlyse deficiency. All patients had hypogonadism, amenorrhea and hypertension at diagnosis. Two sisters were found to be 46,XY with both gonads palpable in the inguinal region. All patients presented hypergonadotrophic hypogonadism, with high levels of ACTH (> 104 ng/mL), suppressed plasmatic renin activity, low levels of potassium (< 2.8 mEq/L) and elevated progesterone levels (> 4.4 ng/mL). Three of them, including two sisters, were homozygous for p.W406R mutation and the other three (two sisters and one cousin) were homozygous for p.R362C. The finding of p.W406R and p.R362C in the CYP17A1 gene here reported in additional families, confirms them as the most frequent mutations causing complete combined 17α-hydroxylase/17,20-lyase deficiency in Brazilian patients.

Defects of steroidogenesis

In the biosynthesis of steroid hormones the neutral lipid cholesterol, a normal constituent of lipid bilayers is transformed via a series of hydroxylation, oxidation, and reduction steps into a vast array of biologically active compounds: mineralocorticoids, glucocorticoids, and sex hormones. Glucocorticoids regulate many aspects of metabolism and immune function, whereas mineralocorticoids help maintain blood volume and control renal excretion of electrolytes. Sex hormones are essential for sex differentiation in male and support reproduction. They include androgens, estrogens, and progestins. A block in the pathway of steroid biosynthesis leads to the lack of hormones downstream and accumulation of the upstream compounds that can activate other members of the steroid receptor family. This review deals with the clinical consequences of these blocks.

17-alpha-hydroxylase deficiency: a case report with clinical and molecular analysis

BACKGROUND

17alpha-Hydroxylase deficiency (17OHD) is a rare disease of congenital adrenal hyperplasia. It is characterised by hypertension, hypokalaemia, primary amenorrhoea. Deficiency of P450c17 enzyme is caused by mutation of the CYP17 gene.

CASE

A 16-year-old female with genotypic 46, XY suffered from 17OHD. She presented with primary amenorrhoea, lack of secondary sexual characteristics, and hypertension. Laboratory tests showed hypokalaemia, low levels of androgens (testosterone and dehydroepiandrosterone), corticosteroid, and high levels of adrenocorticotropic hormone and progesterone. A P409R mutation was found in exon7 of CYP17 gene, revealing homozygosis and confirming diagnosis of 17OHD.

CONCLUSION

17OHD is a rare disease associated with primary amenorrhoea and hypertension. Identification of mutation in CYP17 gene can help to a better understanding of this enzyme deficiency.

Molecular modeling on inhibitor complexes and active-site dynamics of cytochrome P450 C17, a target for prostate cancer therapy

A molecular model for the P450 enzyme cytochrome P450 C17 (CYP17) is presented based on sequence alignments of multiple template structures and homology modeling. This enzyme plays a central role in the biosynthesis of testosterone and is emerging as a major target in prostate cancer, with the recently developed inhibitor abiraterone currently in advanced clinical trials. The model is described in detail, together with its validation, by providing structural explanations to available site-directed mutagenesis data. The CYP17 molecule in this model is in the form of a triangular prism, with an edge of approximately 55 A and a thickness of approximately 37 A. It is predominantly helical, comprising 13 alpha helices interspersed by six 3(10) helices and 11 beta-sheets. Multinanosecond molecular dynamics simulations in explicit solvent have been carried out, and principal components analysis has been used to reveal the details of dynamics around the active site. Coarse-grained methods have also been used to verify low-frequency motions, which have been correlated with active-site gating. The work also describes the results of docking synthetic inhibitors, including the drug abiraterone and the natural substrate pregnenolone, in the CYP17 active site together with molecular dynamics simulations on the complexes.