Cytochrome P450 oxidoreductase deficiency: identification and characterization of biallelic mutations and genotype-phenotype correlations in 35 Japanese patients

Rare forms of congenital adrenal hyperplasia

Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders due to pathogenic variants in genes encoding enzymes and cofactors involved in adrenal steroidogenesis. Although 21-hydroxylase, 11β-hydroxylase, 3β-hydroxysteroid dehydrogenase type 2, 17α-hydroxylase/17,20-lyase, P450 oxidoreductase, steroidogenic acute regulatory protein, cholesterol side-chain cleavage enzyme deficiencies are considered within the definition of CAH, the term 'CAH' is often used to refer to '21-hydroxylase deficiency (21OHD)' since 21OHD accounts for approximately 95% of CAH in most populations. The prevalence of the rare forms of CAH varies according to ethnicity and geographical location. In most cases, the biochemical fingerprint of impaired steroidogenesis points to the specific subtypes of CAH, and genetic testing is usually required to confirm the diagnosis. Despite there are significant variations in clinical characteristics and management, most data about the rare CAH forms are extrapolated from 21OHD. This review article aims to collate the currently available data about the diagnosis and the management of rare forms of CAH.

Exploring Novel Variants of the Cytochrome P450 Reductase Gene (POR) from the Genome Aggregation Database by Integrating Bioinformatic Tools and Functional Assays

Cytochrome P450 oxidoreductase (POR) is an essential redox partner for steroid and drug-metabolizing cytochromes P450 located in the endoplasmic reticulum. Mutations in POR lead to metabolic disorders, including congenital adrenal hyperplasia, and affect the metabolism of steroids, drugs, and xenobiotics. In this study, we examined approximately 450 missense variants of the POR gene listed in the Genome Aggregation Database (gnomAD) using eleven different in silico prediction tools. We found that 64 novel variants were consistently predicted to be disease-causing by most tools. To validate our findings, we conducted a population analysis and selected two variations in POR for further investigation. The human POR wild type and the R268W and L577P variants were expressed in bacteria and subjected to enzyme kinetic assays using a model substrate. We also examined the activities of several cytochrome P450 proteins in the presence of POR (WT or variants) by combining P450 and reductase proteins in liposomes. We observed a decrease in enzymatic activities (ranging from 35% to 85%) of key drug-metabolizing enzymes, supported by POR variants R288W and L577P compared to WT-POR. These results validate our approach of curating a vast amount of data from genome projects and provide an updated and reliable reference for diagnosing POR deficiency.

Diagnostic challenges and management advances in cytochrome P450 oxidoreductase deficiency, a rare form of congenital adrenal hyperplasia, with 46, XX karyotype

Cytochrome P450 oxidoreductase deficiency (PORD) is a rare form of congenital adrenal hyperplasia that can manifest with skeletal malformations, ambiguous genitalia, and menstrual disorders caused by cytochrome P450 oxidoreductase (POR) mutations affecting electron transfer to all microsomal cytochrome P450 and some non-P450 enzymes involved in cholesterol, sterol, and drug metabolism. With the advancement of molecular biology and medical genetics, increasing numbers of PORD cases were reported, and the clinical spectrum of PORD was extended with studies on underlying mechanisms of phenotype-genotype correlations and optimum treatment. However, diagnostic challenges and management dilemma still exists because of unawareness of the condition, the overlapping manifestations with other disorders, and no clear guidelines for treatment. Delayed diagnosis and management may result in improper sex assignment, loss of reproductive capacity because of surgical removal of ruptured ovarian macro-cysts, and life-threatening conditions such as airway obstruction and adrenal crisis. The clinical outcomes and prognosis, which are influenced by specific POR mutations, the presence of additional genetic or environmental factors, and management, include early death due to developmental malformations or adrenal crisis, bilateral oophorectomies after spontaneous rupture of ovarian macro-cysts, genital ambiguity, abnormal pubertal development, and nearly normal phenotype with successful pregnancy outcomes by assisted reproduction. Thus, timely diagnosis including prenatal diagnosis with invasive and non-invasive techniques and appropriate management is essential to improve patients' outcomes. However, even in cases with conclusive diagnosis, comprehensive assessment is needed to avoid severe complications, such as chromosomal test to help sex assignment and evaluation of adrenal function to detect partial adrenal insufficiency. In recent years, it has been noted that proper hormone replacement therapy can lead to decrease or resolve of ovarian macro-cysts, and healthy babies can be delivered by in vitro fertilization and frozen embryo transfer following adequate control of multiple hormonal imbalances. Treatment may be complicated with adverse effects on drug metabolism caused by POR mutations. Unique challenges occur in female PORD patients such as ovarian macro-cysts prone to spontaneous rupture, masculinized genitalia without progression after birth, more frequently affected pubertal development, and impaired fertility. Thus, this review focuses only on 46, XX PORD patients to summarize the potential molecular pathogenesis, differential diagnosis of classic and non-classic PORD, and tailoring therapy to maintain health, avoid severe complications, and promote fertility.

Congenital adrenal hyperplasia, disorders of sex development, and infertility in patients with POR gene pathogenic variants: a systematic review of the literature

BACKGROUND

P450 oxidoreductase (POR) deficiency (PORD) is characterized by congenital adrenal hyperplasia (CAH) and disorders of sex development (DSD) in both sexes. PORD can also associate with skeletal defects. However, the prevalence of these phenotypes is unknown.

AIM

To evaluate the prevalence of CAH, DSD, and infertility of patients with POR gene pathogenic variants by a systematic review of the literature.

METHODS

The literature search was performed through PubMed, MEDLINE, Cochrane, Academic One Files, Google Scholar, and Scopus databases. All studies reporting information on CAH, DSD, testicular adrenal rest tumor (TARTs), and fertility in patients with POR gene pathogenic variants were included. Finally, the prevalence of abnormal phenotypes was calculated.

RESULTS

Of the 246 articles initially retrieved, only 48 were included for a total of 119 (46 males and 73 females) patients with PORD. We also included the case of a male patient who consulted us for CAH and TARTs but without DSD. This patient, found to be a carrier of combined heterozygous POR mutation, reached fatherhood spontaneously. All the patients found had CAH. The presence of DSD was found in 65.2%, 82.1%, and 82.1% of patients with compound heterozygosity, homozygosity, or monoallelic heterozygous variants, respectively. The prevalence was significantly higher in females than in males. The prevalence of TARTs in patients with PORD is 2.7%. Only 5 women with PORD became pregnant after assisted reproductive techniques and delivered a healthy baby. Except for the recently reported proband, no other studies focused on male infertility in patients with POR gene variants.

CONCLUSION

This systematic review of the literature reports the prevalence of CAH, DSD, and TARTs in patients with PORD. The unknown prevalence of POR gene pathogenetic variants and the paucity of studies investigating fertility do not allow us to establish whether PORD is associated with infertility. Further studies on both women and men are needed to clarify this relationship.

Loss of Protein Stability and Function Caused by P228L Variation in NADPH-Cytochrome P450 Reductase Linked to Lower Testosterone Levels

Cytochrome P450 oxidoreductase (POR) is the redox partner of steroid and drug-metabolising cytochromes P450 located in the endoplasmic reticulum. Mutations in POR cause a broad range of metabolic disorders. The POR variant rs17853284 (P228L), identified by genome sequencing, has been linked to lower testosterone levels and reduced P450 activities. We expressed the POR wild type and the P228L variant in bacteria, purified the proteins, and performed protein stability and catalytic functional studies. Variant P228L affected the stability of the protein as evidenced by lower unfolding temperatures and higher sensitivity to urea denaturation. A significant decline in the rate of electron transfer to cytochrome c and thiazolyl blue tetrazolium (MTT) was observed with POR P228L, while activities of CYP3A4 were reduced by 25% and activities of CYP3A5 and CYP2C9 were reduced by more than 40% compared with WT POR. The 17,20 lyase activity of CYP17A1, responsible for the production of the main androgen precursor dehydroepiandrosterone, was reduced to 27% of WT in the presence of the P228L variant of POR. Based on in silico and in vitro studies, we predict that the change of proline to leucine may change the rigidity of the protein, causing conformational changes in POR, leading to altered electron transfer to redox partners. A single amino acid change can affect protein stability and cause a severe reduction in POR activity. Molecular characterisation of individual POR mutations is crucial for a better understanding of the impact on different redox partners of POR.

In Silico Analysis of PORD Mutations on the 3D Structure of P450 Oxidoreductase

Cytochrome P450 oxidoreductase (POR) is a membrane-bound flavoprotein that helps in transferring electrons from its NADPH domain to all cytochrome P450 (CYP450) enzymes. Mutations in the POR gene could severely affect the metabolism of steroid hormones and the development of skeletal muscles, a condition known as Cytochrome P450 oxidoreductase deficiency (PORD). PORD is associated with clinical presentations of disorders of sex development, Antley and Bixler’s syndrome (ABS), as well as an abnormal steroid hormone profile. We have performed an in silico analysis of POR 3D X-ray protein crystal structure to study the effects of reported mutations on the POR enzyme structure. A total of 32 missense mutations were identified, from 170 PORD patients, and mapped on the 3D crystal structure of the POR enzyme. In addition, five of the missense mutations (R457H, A287P, D210G, Y181D and Y607C) were further selected for an in-depth in silico analysis to correlate the observed changes in POR protein structure with the clinical phenotypes observed in PORD patients. Overall, missense mutations found in the binding sites of POR cofactors could lead to a severe form of PORD, emphasizing the importance of POR cofactor binding domains in transferring electrons to the CYP450 enzyme family.

Classic and backdoor pathways of androgen biosynthesis in human sexual development

Both genes and hormones regulate human sexual development. Although ovarian hormones are not essential for female external genitalia development, male sexual development requires the action of testicular testosterone and dihydrotestosterone (DHT). DHT is the most active endogenous androgen formed by the conversion of testosterone in genital skin. This synthesis route from cholesterol to DHT is called the conventional classic pathway. Recent investigations have reported an alternative ("backdoor") route for DHT formation that bypasses fetal testicular testosterone. This alternative route plays a crucial role in human hyperandrogenic disorders like congenital adrenal hyperplasia caused by P450c21 deficiency, polycystic ovary syndrome, and P450 oxidoreductase deficiency. In addition, mutations in AKR1C2 and AKR1C4, genes encoding 3α-reductases, have been implicated in disorders of sexual development, indicating that both the classic and backdoor routes are required for normal human male sexual development. More recently, androsterone was found to be the primary androgen of the human backdoor route. Androsterone and steroidal substrates specific to the backdoor route are predominantly found in the placenta, liver, and adrenal glands rather than in the testes. These findings are essential to understanding human sexual development.

Estrogen Promotes Microvascularization in the Fetus and Thus Vascular Function and Insulin Sensitivity in Offspring

We have shown that normal weight offspring born to estrogen-deprived baboons exhibited insulin resistance, although liver and adipose function and insulin receptor and glucose transporter expression were unaltered. The blood microvessels have an important role in insulin action by delivering insulin and glucose to target cells. Although little is known about the regulation of microvessel development during fetal life, estrogen promotes capillary proliferation and vascular function in the adult. Therefore, we tested the hypothesis that estrogen promotes fetal microvessel development and thus vascular function and insulin sensitivity in offspring. Capillary/myofiber ratio was decreased 75% (P < 0.05) in skeletal muscle, a major insulin target tissue, of fetal baboons in which estradiol levels were depleted by administration of aromatase inhibitor letrozole. This was sustained after birth, resulting in a 50% reduction (P < 0.01) in microvessel expansion; 65% decrease (P < 0.01) in arterial flow-mediated dilation, indicative of vascular endothelial dysfunction; and 35% increase (P < 0.01) in blood pressure in offspring from estrogen-deprived baboons, changes prevented by letrozole and estradiol administration. Along with vascular dysfunction, peak insulin and glucose levels during a glucose tolerance test were greater (P < 0.05 to P < 0.01) and the homeostasis model of insulin resistance 2-fold higher (P < 0.01) in offspring of letrozole-treated than untreated animals, indicative of insulin resistance. This study makes the novel discovery that estrogen promotes microvascularization in the fetus and thus normal vascular development and function required for eliciting insulin sensitivity in offspring and that placental hormonal secretions, independent from improper fetal growth, are an important determinant of risk of developing insulin resistance.

Congenital Adrenal Hyperplasia-Current Insights in Pathophysiology, Diagnostics, and Management

Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders affecting cortisol biosynthesis. Reduced activity of an enzyme required for cortisol production leads to chronic overstimulation of the adrenal cortex and accumulation of precursors proximal to the blocked enzymatic step. The most common form of CAH is caused by steroid 21-hydroxylase deficiency due to mutations in CYP21A2. Since the last publication summarizing CAH in Endocrine Reviews in 2000, there have been numerous new developments. These include more detailed understanding of steroidogenic pathways, refinements in neonatal screening, improved diagnostic measurements utilizing chromatography and mass spectrometry coupled with steroid profiling, and improved genotyping methods. Clinical trials of alternative medications and modes of delivery have been recently completed or are under way. Genetic and cell-based treatments are being explored. A large body of data concerning long-term outcomes in patients affected by CAH, including psychosexual well-being, has been enhanced by the establishment of disease registries. This review provides the reader with current insights in CAH with special attention to these new developments.

Congenital adrenal hyperplasia due to P450 oxidoreductase deficiency

OBJECTIVE

To raise awareness of Cytochrome P450 Oxidoreductase Deficiency (PORD, a rare form of congenital adrenal hyperplasia (CAH), through a case of pregnant woman with virilization symptoms.

CASE DESCRIPTION

A 30-year-old Chinese woman was referred to hospital after 7 years of presenting signs of virilization, including voice deepening, acromegaly, hirsutism, clitoromegaly, and acne. These symptoms appeared since her third gestation. Her second birth died 9 hours after birth and had signs of clitoris hypertrophy. Her third born was a son who presented with flat nose, radius and humerus bone malformation, and small penis at birth. Panel of POR-related genetic tests revealed that the patient carried c.1370 G>A (p.R457H), which is a POR heterozygous gene, while her husband carried a POR heterozygous gene as well, c.1379 C>A (p.S460Y). Two heterozygous mutations of the POR were found in her son: c.1370 G>A and c.1379 C>A. In PORD, c.1370 G>A (p.R457H) was reported as a susceptible gene, while c.1379 C>A (p.S460Y) has not been reported as responsible for the disease so far.

DISCUSSION AND LITERATURE REVIEW

PORD is a rare form of CAH and caused by POR gene mutations. Most PORD patients are identified and diagnosed in pediatrics department. Internal medicine and obstetrics physicians are unfamiliar with the disease. As clinical manifestations are diverse, PORD could be easy to miss or to be misdiagnosed. Typical clinical manifestation includes adrenal insufficiency-related symptoms, such as bone malformations and sexual development disorders. PORD is diagnosed through genetic testing. Investigations of steroid metabolic products in urine through gas chromatography-mass spectrometry or liquid chromatography-mass spectrometry are also helpful for the diagnosis, but neither of them are widely available in China. In this case, the patient had a history of infertility, and her third child was born with congenital defect and carried a PORD-related gene. In general clinical practice, if a pregnant woman presents with abnormal virilization symptoms, CAH possibilities should be considered, including rare causes such as PORD.

CONCLUSION

PORD is a rare autosomal recessive genetic disease. We summarised the clinical characteristics and genotypes that were previously reported in the Chinese population and identified a novel mutation.

Clinical guidelines for the diagnosis and treatment of 21-hydroxylase deficiency (2021 revision)

Congenital adrenal hyperplasia is a category of disorders characterized by impaired adrenocortical steroidogenesis. The most frequent disorder of congenital adrenal hyperplasia is 21-hydroxylase deficiency, which is caused by pathogenic variants of CAY21A2 and is prevalent between 1 in 18,000 and 20,000 in Japan. The clinical guidelines for 21-hydroxylase deficiency in Japan have been revised twice since a diagnostic handbook in Japan was published in 1989. On behalf of the Japanese Society for Pediatric Endocrinology, the Japanese Society for Mass Screening, the Japanese Society for Urology, and the Japan Endocrine Society, the working committee updated the guidelines for the diagnosis and treatment of 21-hydroxylase deficiency published in 2014, based on recent evidence and knowledge related to this disorder. The recommendations in the updated guidelines can be applied in clinical practice considering the risks and benefits to each patient.

Infertility treatment for Chinese women with P450 oxidoreductase deficiency: Prospect on clinical management from IVF to FET

Cytochrome P450 oxidoreductase deficiency (PORD) is a rare recessive disease with multiple clinical manifestations, which is usually diagnosed in neonates and children because of ambiguous genitalia or skeletal malformations. Moreover, the paucity of studies does not allow us to establish whether adult-onset PORD is associated with infertility. Here, we report clinical and laboratory findings in two phenotypically normal women diagnosed with PORD who underwent in vitro fertilization (IVF) and frozen embryo transfer (FET). We modified the gonadotropin stimulation protocol during controlled ovarian hyperstimulation (COH) and suggest the use of the vaginal 17β-estradiol route for endometrium preparation in hormone replacement therapy (HRT) cycles. We presume that PORD may be associated with infertility in several aspects, including disordered steroidogenesis, endometrium impairment, attenuation of drug metabolism, and the high risk of miscarriage. Our observations will help the early diagnosis and make a tailored approach to infertility management in adult-onset PORD.

Antley-Bixler syndrome arising from compound heterozygotes in the P450 oxidoreductase gene: a case report

Antley-Bixler syndrome (ABS) arising from P450 oxidoreductase deficiency (PORD) is a rare, distinct craniosynostosis syndrome, accompanied by ambiguous genitalia and impaired steroidogenesis. It is reported that this disorder is caused by mutations in the P450 oxidoreductase (POR; OMIM #124015) gene via autosomal recessive inheritance. In this study, we performed a molecular analysis to verify the genetic etiology of ABS in an infant. Initially, medical exome sequencing was applied using the parents' peripheral blood genome DNA. Next, bidirectional Sanger sequencing and quantitative real-time PCR (qRT-PCR) were conducted to confirm the sequencing results. The infant was diagnosed as ABS at birth, with typical midface hypoplasia, craniosynostosis, femoral bowing, radio-ulnar synostosis, and genital anomalies. She died two months later due to severe pneumonia and congenital heart disease. The medical exome sequencing and Sanger sequencing revealed the missense mutation c.1370G>A (p.R457H) in exon 12 of POR was inherited from the father. In addition, the qRT-PCR analysis verified an exon 5 microdeletion in the POR gene of the infant and her mother. While p.R457H is a well-known pathogenic mutation, the POR exon 5 deletion is absent from the public databases. However, it is classified as pathogenic according to the American College of Medical Genetics and Genomics (ACMG) guidelines based on the evidence of PVS1, PM2, and PM3. In conclusion, this infant with ABS carried compound heterozygotic mutations in the POR gene; one was a paternal missense mutation, and the other was a maternal novel microdeletion. The mutations were inherited from the paternal grandfather and maternal grandfather, respectively. This detailed case report enriches our knowledge of the POR mutation spectrum and ABS pathogenesis.

Cytochrome P450 oxidoreductase deficiency caused by a novel mutation in the POR gene in two siblings: case report and literature review

INTRODUCTION

P450 oxidoreductase (POR) deficiency is a rare form of congenital adrenal hyperplasia. In both genders, it can lead to ambiguous genitalia, impaired steroidogenesis, and skeletal findings similar to those of Antley-Bixler syndrome.

CASES

We describe two cases of POR deficiency. The first case was an 8.5-year-old girl who was admitted to our clinic due to ambiguous genitalia. Karyotype was 46, XX. There were mild dysmorphic facial findings and mild metacarpophalangeal joint deformity. The patient's basal cortisol and ACTH levels were normal, while 17-hydroxyprogesterone (17OHP) levels were high. Peak cortisol response to the ACTH stimulation test was found to be insufficient. Our second case, a sibling of the first case, was admitted for routine checkup at the age of 15 months. As in our first case, there were dysmorphic facial findings and metacarpophalangeal joint deformity. The genital structure was normal. Karyotype was 46, XY. Basal cortisol and ACTH levels were normal, while 17OHP level was slightly high. Peak cortisol response to the ACTH stimulation test was found to be insufficient. Based on our findings, POR deficiency was considered in both of these cases and NM_000941.3:c.929_937delTCTCGGACT(p.Ile310_Ser313delinsThr) (homozygous) mutation was detected in the POR gene that had not previously been described.

CONCLUSION

We detected a novel variant in the POR gene in two sibling cases with adrenal insufficiency, dysmorphic face, and mild skeletal findings. While the detected mutation caused ambiguous genitalia in the female case, it did not cause ambiguous genitalia in the male case.

Non-classic cytochrome P450 oxidoreductase deficiency strongly linked with menstrual cycle disorders and female infertility as primary manifestations

STUDY QUESTION

Can cytochrome P450 oxidoreductase deficiency (PORD) be revealed in adult women with menstrual disorders and/or infertility?

SUMMARY ANSWER

PORD was biologically and genetically confirmed in five adult women with chronically elevated serum progesterone (P) who were referred for oligo-/amenorrhea and/or infertility.

WHAT IS KNOWN ALREADY

PORD is an autosomal recessive disease typically diagnosed in neonates and children with ambiguous genitalia and/or skeletal abnormalities. It is responsible for the decreased activity of several P450 enzymes, including CYP21A2, CYP17A1 and CYP19A1, that are involved in adrenal and/or gonadal steroidogenesis. Little is known about the optimal way to investigate and treat patients with adult-onset PORD.

STUDY DESIGN, SIZE, DURATION

In this series, we report five adult females who were evaluated in three tertiary endocrine reproductive departments between March 2015 and September 2018.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Five women aged 19-38 years were referred for unexplained oligo-/amenorrhea and/or infertility. Genetic testing excluded 21-hydroxylase deficiency (21OH-D), initially suspected due to the increased 17-hydroxyprogesterone (17-OHP) levels. Extensive phenotyping, steroid profiling by mass spectrometry, pelvic imaging and next-generation sequencing of 84 genes involved in gonadal and adrenal disorders were performed in all patients. IVF followed by frozen embryo transfer (ET) under glucocorticoid suppression therapy was performed for two patients.

MAIN RESULTS AND THE ROLE OF CHANCE

All patients had oligomenorrhea or amenorrhea. None had hyperandrogenism. Low-normal serum estradiol (E2) and testosterone levels contrasted with chronically increased serum P and 17-OHP levels, which further increased after adrenocorticotrophic hormone (ACTH) administration. Despite excessive P, 17OH-P and 21-deoxycortisol rise after ACTH stimulation suggesting non-classic 21OH-D, CYP21A2 sequencing did not support this hypothesis. Basal serum cortisol levels were low to normal, with inadequate response to ACTH in some women, suggesting partial adrenal insufficiency. All patients harbored rare biallelic POR mutations classified as pathogenic or likely pathogenic according to the American College of Medical Genetics and Genomics standards. Pelvic imaging revealed bilateral ovarian macrocysts in all women. IVF was performed for two women after retrieval of a normal oocyte number despite very low E2 levels during ovarian stimulation. Frozen ET under glucocorticoid suppression therapy led to successful pregnancies.

LIMITATIONS, REASONS FOR CAUTION

The number of patients described here is limited and these data need to be confirmed on a larger number of women with non-classic PORD.

WIDER IMPLICATIONS OF THE FINDINGS

The diagnosis of PORD must be considered in infertile women with chronically elevated P and 17OH-P levels and ovarian macrocysts. Differentiation of this entity from non-classic 21OH-D is important, as the multiple enzyme deficiency requires a specific management. Successful fertility induction is possible by IVF, providing that P levels be sufficiently suppressed by glucocorticoid therapy prior to implantation.

STUDY FUNDING/COMPETING INTEREST(S)

No specific funding was used for this study. There are no potential conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Successful live birth in a Chinese woman with P450 oxidoreductase deficiency through frozen-thawed embryo transfer: a case report with review of the literature

Background

Congenital adrenal hyperplasia (CAH) caused by P450 oxidoreductase deficiency (PORD) in 46, XX patients is characterized by genital ambiguity, primary amenorrhea, absent or incomplete sexual maturation, infertility, skeletal malformations and so on. But few pregnancies have been reported from these female patients with PORD.

Case description

A 29-year-old Chinese woman with PORD due to the compound heterozygous mutation (c.1370G > A/c.1196_1204del) in the P450 oxidoreductase (POR) gene had suffered from primary amenorrhea and infertility. She had one cancelled cycle of ovulation induction due to low serum estradiol(E₂), high progesterone(P) levels and thin endometrium, then in vitro fertilization (IVF) was recommended. At the first IVF cycle, 4 oocytes were retrieved and 4 viable embryos were cryopreserved due to thin endometrium associated with low E₂ and prematurely elevated P after ovarian stimulation, even though oral dexamethasone were used to control adrenal P overproduction at the same time. When basal P fell to < 1.5 ng/ml after the therapy of oral dexamethasone, artificial endometrial preparation and frozen embryo transfer were performed, resulting in a twin pregnancy. She delivered a healthy boy and a healthy girl by caesarean section at 37 weeks and 2 days of gestation. After the literature search in PORD women, no spontaneous pregnancy has been reported and only two previous case reports of 3 successful pregnancies through IVF were summarized.

Conclusions

It is the third report that successful pregnancy was achieved in a CAH woman caused by a compound heterozygous POR mutation, with primary amenorrhea and disorders of steroidogenesis. It seemed that disorders of steroidogenesis caused by PORD didn’t impair the developmental potential of oocytes. IVF and frozen embryo transfer after adequate hormonal control and endometrial preparation should be an effective infertility treatment for PORD women.

A Case of Salt-Wasting 21-Hydroxylase Deficiency With Resistance to Aldosterone due to Urinary Tract Infection

Classic salt-wasting 21-hydroxylase deficiency (21-OHD) often requires fludrocortisone (FC) replacement. However, the optimal dose of FC varies between patients and the dose needs to be adjusted depending on the degree of symptoms. Further, the aldosterone resistance due to urinary tract infections causes salt-wasting symptoms. We recently encountered a patient with 21-OHD who required up to 0.36 mg/day of FC in order to control hyperkalemia despite adequate hydrocortisone (HC) administration. This condition was presumed to be due to aldosterone resistance complications associated with urinary tract infections. Thus, if the initial treatment of 21-OHD with HC and FC is resistant, then one should consider complications that may cause aldosterone resistance, such as urinary tract infections.

Clinical characteristics of cytochrome P450 oxidoreductase deficiency: a nationwide survey in Japan

Cytochrome P450 oxidoreductase deficiency (PORD) is a disorder of steroidogenesis that causes various symptoms such as skeletal malformations, disorders of sex development, and adrenal insufficiency. The aim of this study was to elucidate the clinical characteristics, especially age at diagnosis and treatment, of PORD from the perinatal period to adulthood in Japan. The first questionnaire was sent to 183 council members of the Japanese Society for Pediatric Endocrinology on 1 September 2018. The response rate was 65%, and a total of 39 patients with PORD were examined at 20 hospitals. The second questionnaire was sent in November 2018 to the council members examining these 39 patients with PORD. The response rate was 77%, and we received clinical information on 30 of the 39 patients. The two novel clinical findings were the age at diagnosis and the treatment of Japanese patients with PORD. In many cases, PORD can be diagnosed at <3 months of age. Hydrocortisone as the primary treatment during infancy can be used daily or in stressful situations; however, because patients with PORD generally have mild to moderate adrenal insufficiency, some might be able to avoid hydrocortisone treatment. Patients with PORD should be carefully followed up, and treatment should be optimized as for patients with other types of adrenal insufficiency. Other characteristics in the present study were similar to those described in previous reports.

Epigenetic alterations in cytochrome P450 oxidoreductase (Por) in sperm of rats exposed to tetrahydrocannabinol (THC)

As marijuana legalization is increasing, research regarding possible long-term risks for users and their offspring is needed. Little data exists on effects of paternal tetrahydrocannabinol (THC) exposure prior to reproduction. This study determined if chronic THC exposure alters sperm DNA methylation (DNAm) and if such effects are intergenerationally transmitted. Adult male rats underwent oral gavage with THC or vehicle control. Differentially methylated (DM) loci in motile sperm were identified using reduced representation bisulfite sequencing (RRBS). Another cohort was injected with vehicle or THC, and sperm DNAm was analyzed. Finally, THC-exposed and control adult male rats were mated with THC-naïve females. DNAm levels of target genes in brain tissues of the offspring were determined by pyrosequencing. RRBS identified 2,940 DM CpGs mapping to 627 genes. Significant hypermethylation was confirmed (p < 0.05) following oral THC administration for cytochrome P450 oxidoreductase (Por), involved in toxin processing and disorders of sexual development. Por hypermethylation was not observed after THC injection or in the subsequent generation. These results support that THC alters DNAm in sperm and that route of exposure can have differential effects. Although we did not observe evidence of intergenerational transmission of the DNAm change, larger studies are required to definitively exclude this possibility.

Clinical, endocrinological, and molecular features of four Korean cases of cytochrome P450 oxidoreductase deficiency

PURPOSE

Cytochrome P450 oxidoreductase (POR) deficiency is a rare autosomal recessive disorder caused by mutations in the POR gene encoding an electron donor for all microsomal P450 enzymes. It is characterized by adrenal insufficiency, ambiguous genitalia, maternal virilization during pregnancy, and skeletal dysplasia. In this study, we investigated the clinical, hormonal, and molecular characteristics of patients with POR deficiency in Korea.

METHODS

This study included four patients with POR deficiency confirmed by biochemical and molecular analysis of POR. Clinical and biochemical findings were reviewed retrospectively. Mutation analysis of POR was performed by Sanger sequencing after polymerase chain reaction amplification of all coding exons and the exon-intron boundaries.

RESULTS

All patients presented with adrenal insufficiency and ambiguous genitalia regardless of their genetic sex. Two patients harbored homozygous p.R457H mutations in POR and presented with adrenal insufficiency and genital ambiguity without skeletal phenotypes. The other two patients with compound heterozygous mutations of c.[1329_1330insC];[1370G&gt;A] (p.[I444Hfs*6];[R457H]) manifested skeletal abnormalities, such as craniosynostosis and radiohumeral synostosis, suggesting Antley-Bixler syndrome. They also had multiple congenital anomalies involving heart, kidney, and hearing ability. All patients were treated with physiologic doses of oral hydrocortisone.

CONCLUSION

We report the cases of 4 patients with POR deficiency identified by mutation analysis of POR. Although the study involved a small number of patients, the POR p.R457H mutation was the most common, suggesting founder effect in Korea. POR deficiency is rare and can be misdiagnosed as 21-hydroxylase or 17α-hydroxylase/17,20-lyase deficiency. Therefore, molecular analysis is critical for confirmatory diagnosis.

Molecular Basis of CYP19A1 Deficiency in a 46,XX Patient With R550W Mutation in POR: Expanding the PORD Phenotype

CONTEXT

Mutations in cytochrome P450 oxidoreductase (POR) cause a form of congenital adrenal hyperplasia (CAH). We report a novel R550W mutation in POR identified in a 46,XX patient with signs of aromatase deficiency.

OBJECTIVE

Analysis of aromatase deficiency from the R550W mutation in POR.

DESIGN, SETTING, AND PATIENT

Both the child and the mother had signs of virilization. Ultrasound revealed the presence of uterus and ovaries. No defects in CYP19A1 were found, but further analysis with a targeted Disorders of Sexual Development NGS panel (DSDSeq.V1, 111 genes) on a NextSeq (Illumina) platform in Madrid and Barcelona, Spain, revealed compound heterozygous mutations c.73_74delCT/p.L25FfsTer93 and c.1648C > T/p.R550W in POR. Wild-type and R550W POR were produced as recombinant proteins and tested with multiple cytochrome P450 enzymes at University Children's Hospital, Bern, Switzerland.

MAIN OUTCOME MEASURE AND RESULTS

POR-R550W showed 41% of the WT activity in cytochrome c and 7.7% activity for reduction of MTT. Assays of CYP19A1 showed a severe loss of activity, and CYP17A1 as well as CYP21A2 activities were also lost by more than 95%. Loss of CYP2C9, CYP2C19, and CYP3A4 activities was observed for the R550W-POR. Predicted adverse effect on aromatase activity as well as a reduction in binding of NADPH was confirmed.

CONCLUSIONS

Pathological effects due to POR-R550W were identified, expanding the knowledge of molecular pathways associated with aromatase deficiency. Screening of the POR gene may provide a diagnosis in CAH without defects in genes for steroid metabolizing enzymes.

P450 Oxidoreductase Deficiency: A Systematic Review and Meta-analysis of Genotypes, Phenotypes, and Their Relationships

CONTEXT

P450 oxidoreductase deficiency (PORD) is a rare genetic disorder that is associated with significant morbidity. However there has been limited analysis of reported PORD cases.

OBJECTIVE

To determine, based on the cohort of reported PORD cases, genotype-phenotype relationships for skeletal malformations, maternal virilisation in pregnancy, adrenal insufficiency, and disorders of sexual development (DSD).

DATA SOURCES

PubMed and Web of Science from January 2004 to February 2018.

STUDY SELECTION

Published case reports/series of patients with PORD. Eligible patients were unique, had biallelic mutations, and their clinical features were reported.

DATA EXTRACTION

Patient data were manually extracted from the text of case reports/series. A malformation score, representing the severity of skeletal malformations, was calculated for each patient.

DATA SYNTHESIS

Of the 211 patients published in the literature, 90 were eligible for inclusion. More than 60 unique mutations were identified in this cohort. Four groups of mutations were identified, through regression modeling, as having significantly different skeletal malformation scores. Maternal virilization in pregnancy, reported for 21% of patients, was most common for R457H mutations. Adrenal insufficiency occurred for the majority of patients (78%) and was typically mild, with homozygous R457H mutations being the least deficient. DSD affected most patients (72%), but were less common for males (46XY) with homozygous R457H mutations.

CONCLUSIONS

PORD is a complex disorder with many possible mutations affecting a large number of enzymes. By analyzing the cohort of reported PORD cases, this study identified clear relationships between genotype and several important phenotypic features.

Congenital Adrenal Hyperplasias Presenting in the Newborn and Young Infant

Congenital adrenal hyperplasia includes autosomal recessive conditions that affect the adrenal cortex steroidogenic enzymes (cholesterol side-chain cleavage enzyme; 3β-hydroxysteroid dehydrogenase; 17α-hydroxylase/17,20 lyase; P450 oxidoreductase; 21-hydroxylase; and 11β-hydroxylase) and proteins (steroidogenic acute regulatory protein). These are located within the three major pathways of the steroidogenic apparatus involved in the production of mineralocorticoids, glucocorticoids, and androgens. Many countries have introduced newborn screening program (NSP) based on 17-OH-progesterone (17-OHP) immunoassays on dried blood spots, which enable faster diagnosis and treatment of the most severe forms of 21-hydroxylase deficiency (21-OHD). However, in several others, the use of this diagnostic tool has not yet been implemented and clinical diagnosis remains challenging, especially for males. Furthermore, less severe classic forms of 21-OHD and other rarer types of CAHs are not identified by NSP. The aim of this mini review is to highlight both the main clinical characteristics and therapeutic options of these conditions, which may be useful for a differential diagnosis in the neonatal period, while contributing to the biochemical evolution taking place in the steroidogenic field. Currently, chromatographic techniques coupled with tandem mass spectrometry are gaining attention due to an increase in the reliability of the test results of NPS for detecting 21-OHD. Furthermore, the possibility of identifying CAH patients that are not affected by 21-OHD but presenting elevated levels of 17-OHP by NSP and the opportunity to include the recently investigated 11-oxygenated androgens in the steroid profiles are promising tools for a more precise diagnosis and monitoring of some of these conditions.

Novel phenotypes and genotypes in Antley-Bixler syndrome caused by cytochrome P450 oxidoreductase deficiency: based on the first cohort of Chinese children

Background

Antley-Bixler syndrome (ABS) caused by P450 oxidoreductase deficiency (PORD) is a congenital adrenal hyperplasia with skeletal malformations and disordered sex development in both sexes. There have been no reports of ABS caused by PORD in Chinese children.

Methods

We described the clinical and genetic characteristics of eight Chinese children with ABS caused by PORD and compared them with those of subjects in previous studies.

Results

Eight patients, aged 6 months–17.8 years, showed strikingly similar craniofacial malformations. We first described four unreported features: lower eyelid fat pads (4/8), prominent lower eyelid-zygoma transverse line (4/8), underdeveloped or absent antihelix (5/8) and single earlobe crease (5/8). Five 46, XY patients presented various degrees of undervirilization, while three 46, XX cases showed masculinization. Basal endocrine measurements revealed the following consistent results: normal cortisol; elevated adrenocorticotropic hormone, progesterone, pregnenolone, 17-hydroxypropgesterone, and corticosterone; and decreased or normal testosterone/oestradiol. We identified three previously reported variants and four novel variants (c.51719_51710delGGCCCCTGTGinsC, p.D210G, p.Y248X and p.R554X) of POR. The most prevalent variant was p.R457H (8/16). The hydrocortisone dosages of patients differed because of variable degrees of adrenal insufficiency.

Conclusions

We described novel phenotypes and genotypes of ABS caused by PORD. The variant p.R457H was the most prevalent in this cohort. All subjects had combined characteristics of 17-hydroxylase and 21-hydroxylase deficiency. Steroid replacement therapy for patients with PORD requires individually tailored dosing.

Steroid Metabolome Analysis in Disorders of Adrenal Steroid Biosynthesis and Metabolism

Steroid biosynthesis and metabolism are reflected by the serum steroid metabolome and, in even more detail, by the 24-hour urine steroid metabolome, which can provide unique insights into alterations of steroid flow and output indicative of underlying conditions. Mass spectrometry-based steroid metabolome profiling has allowed for the identification of unique multisteroid signatures associated with disorders of steroid biosynthesis and metabolism that can be used for personalized approaches to diagnosis, differential diagnosis, and prognostic prediction. Additionally, steroid metabolome analysis has been used successfully as a discovery tool, for the identification of novel steroidogenic disorders and pathways as well as revealing insights into the pathophysiology of adrenal disease. Increased availability and technological advances in mass spectrometry-based methodologies have refocused attention on steroid metabolome profiling and facilitated the development of high-throughput steroid profiling methods soon to reach clinical practice. Furthermore, steroid metabolomics, the combination of mass spectrometry-based steroid analysis with machine learning-based approaches, has facilitated the development of powerful customized diagnostic approaches. In this review, we provide a comprehensive up-to-date overview of the utility of steroid metabolome analysis for the diagnosis and management of inborn disorders of steroidogenesis and autonomous adrenal steroid excess in the context of adrenal tumors.

46,XX DSD due to Androgen Excess in Monogenic Disorders of Steroidogenesis: Genetic, Biochemical, and Clinical Features

The term 'differences of sex development' (DSD) refers to a group of congenital conditions that are associated with atypical development of chromosomal, gonadal, or anatomical sex. Disorders of steroidogenesis comprise autosomal recessive conditions that affect adrenal and gonadal enzymes and are responsible for some conditions of 46,XX DSD where hyperandrogenism interferes with chromosomal and gonadal sex development. Congenital adrenal hyperplasias (CAHs) are disorders of steroidogenesis that mainly involve the adrenals (21-hydroxylase and 11-hydroxylase deficiencies) and sometimes the gonads (3-beta-hydroxysteroidodehydrogenase and P450-oxidoreductase); in contrast, aromatase deficiency mainly involves the steroidogenetic activity of the gonads. This review describes the main genetic, biochemical, and clinical features that apply to the abovementioned conditions. The activities of the steroidogenetic enzymes are modulated by post-translational modifications and cofactors, particularly electron-donating redox partners. The incidences of the rare forms of CAH vary with ethnicity and geography. The elucidation of the precise roles of these enzymes and cofactors has been significantly facilitated by the identification of the genetic bases of rare disorders of steroidogenesis. Understanding steroidogenesis is important to our comprehension of differences in sexual development and other processes that are related to human reproduction and fertility, particularly those that involve androgen excess as consequence of their impairment.

Transcriptional Regulation of Ovarian Steroidogenic Genes: Recent Findings Obtained from Stem Cell-Derived Steroidogenic Cells

Ovaries represent one of the primary steroidogenic organs, producing estrogen and progesterone under the regulation of gonadotropins during the estrous cycle. Gonadotropins fluctuate the expression of various steroidogenesis-related genes, such as those encoding steroidogenic enzymes, cholesterol deliverer, and electronic transporter. Steroidogenic factor-1 (SF-1)/adrenal 4-binding protein (Ad4BP)/NR5A1 and liver receptor homolog-1 (LRH-1) play important roles in these phenomena via transcriptional regulation. With the aid of cAMP, SF-1/Ad4BP and LRH-1 can induce the differentiation of stem cells into steroidogenic cells. This model is a useful tool for studying the molecular mechanisms of steroidogenesis. In this article, we will provide insight into the transcriptional regulation of steroidogenesis-related genes in ovaries that are revealed from stem cell-derived steroidogenic cells. Using the cells derived from the model, novel SF-1/Ad4BP- and LRH-1-regulated genes were identified by combined DNA microarray and promoter tiling array analyses. The interaction of SF-1/Ad4BP and LRH-1 with transcriptional regulators in the regulation of ovarian steroidogenesis was also revealed.

Monogenic Disorders of Adrenal Steroidogenesis

Disorders of adrenal steroidogenesis comprise autosomal recessive conditions affecting steroidogenic enzymes of the adrenal cortex. Those are located within the 3 major branches of the steroidogenic machinery involved in the production of mineralocorticoids, glucocorticoids, and androgens. This mini review describes the principles of adrenal steroidogenesis, including the newly appreciated 11-oxygenated androgen pathway. This is followed by a description of pathophysiology, biochemistry, and clinical implications of steroidogenic disorders, including mutations affecting cholesterol import and steroid synthesis, the latter comprising both mutations affecting steroidogenic enzymes and co-factors required for efficient catalysis. A good understanding of adrenal steroidogenic pathways and their regulation is crucial as the basis for sound management of these disorders, which in the majority present in early childhood.

In vitro fertilization-frozen embryo transfer in a patient with cytochrome P450 oxidoreductase deficiency: a case report

Cytochrome P450 enzymes are required for the synthesis of cholesterol and steroid hormones. Cytochrome P450 oxidoreductase (POR) donates electrons to microsomal cytochrome P450 enzymes. POR deficiency (PORD) is a rare autosomal recessive disease. In patients with PORD, steroid hormone synthesis is disrupted, which can cause infertility. The objective of this study was to report on a case of in vitro fertilization-frozen embryo transfer (IVF-FET) in a patient with PORD. The patient's hormone (i.e. 17α-hydroxyprogesterone) and electrolyte levels were within normal ranges ordinarily. Upon controlled ovarian stimulation, follicle growth was normal, but serum estrogen and progesterone levels were low and high, respectively. The serum progesterone level was elevated after long-acting gonadotropin-releasing hormone agonist treatment, and an endometrial biopsy showed a change in the proliferative phase. Genetic tests detected homozygous mutations (c.976 T > G, p.Y326D) in exon 10 of the POR gene. The frozen embryo was transferred during the administration of hormone replacement therapy. No significant morphological or metabolic abnormalities were observed in the neonate. Our findings suggest that infertile women with normal hormone levels may have metabolic diseases such as PORD. Further studies are needed to determine the cause of these diseases and to assist pregnancy in such women.

Longitudinal serum and urine steroid metabolite profiling in a 46,XY infant with prenatally identified POR deficiency

Although POR deficiency (PORD) is assumed to be accompanied by excessive placental androgen accumulation and enhanced adrenal and testicular androgen production via the backdoor pathway as well as compromised testicular androgen production via the frontdoor pathway, there is no direct evidence for the flux of excessive placental androgens into the fetal circulation and for the production of dihydrotestosterone (DHT) via the backdoor pathway. We examined longitudinal serum and urine steroid metabolite profiles in a 46,XY infant with PORD who was prenatally identified because of the progressive fetal masculinization and maternal virilization from the mid-gestation and the presence of fetal radio-humeral synostosis and was confirmed to have compound heterozygous mutations of POR (p.Q201X and p.R457H). The results showed (1) markedly and inappropriately elevated serum androstenedione and testosterone (T) values at birth, (2) a markedly increased serum DHT value with a normal DHT/T ratio at birth, (3) transient elevation of serum T and DHT values accompanied by a normal DHT/T ratio and concomitant elevations of intermediate steroid metabolites on both the frontdoor and backdoor pathways at 30 days of age, and (4) persistent PORD-compatible urine steroid profiles. Although the data obtained from a single infantile patient are too premature to be generalized, they imply: (1) the transfer of excessive placental androgens into the fetal as well as the maternal circulations from the mid-gestation, (2) lack of a clinically discernible amount of DHT production via the adrenal backdoor pathway around birth, and (3) the activation of both the frontdoor and backdoor pathways in the testis around the mini-puberty, with no production of a clinically discernible amount of DHT via the testicular backdoor pathway.

Cytochrome P450 oxidoreductase deficiency caused by R457H mutation in POR gene in Chinese: case report and literature review

Background

Cytochrome P450 oxidoreductase deficiency (PORD) is a rare disease exhibiting a variety of clinical manifestations. It can be difficult to differentiate with other diseases such as 21-hydroxylase deficiency (21-OHD), polycystic ovary syndrome (PCOS) and Antley–Bixler syndrome (ABS). Nearly 100 cases of PORD have been reported worldwide. However, the genetic characters and clinical management are still unclear, especially in China.

Case presentation

In this study, we report a 27-year-old female Chinese patient who first presented with amenorrhea and recurrence of large ovary cyst. She was misdiagnosed with PCOS and non-classical 21-OHD due to ovary cysts and elevated 17-hydroxy-progesterone. The patient’s complaining of a mild difficulty of bending the metacarpophalangeal joints reminded us to consider PORD, which usually presents with skeletal deformities and sexual dysfunction. The diagnosis of PORD was confirmed by genetic analyses, which showed the patient harboring a homozygous missense mutation in the POR gene (R457H) and her parents carrying the heterozygous mutation. The patient was treated with low-dose corticosteroids and estrogen/progesterone sequential therapy, and her ovarian cyst gradually reduced with regular menstruation in the follow-up. Moreover, the clinical and genetic characteristics of 104 previously reported PORD cases were also summarized and analyzed.

Conclusions

PORD is a very rare disease which can be easily misdiagnosed in mild cases. Clinicians should keep in mind of this disease in patients with sexual dysfunction, especially combined with special skeletal deformities. Our data could provide a consciously understanding of this disease for clinic practicers. Low-dose corticosteroids combined with estrogen/progesterone sequential therapy will be effective in PORD patients with recurrence of large ovary cyst. The fact that the reported PORD patients in China carrying an identical variant R457H in POR gene also give us a viewpoint that R457H mutation in POR gene maybe important in causing PORD in Chinese as same as in Japanese.

P450 Oxidoreductase deficiency: Analysis of mutations and polymorphisms

Cytochrome P450 oxidoreductase (POR) is required for metabolic reactions of steroid and drug metabolizing cytochrome P450 proteins located in endoplasmic reticulum. Mutations in POR cause a complex set of disorders resembling combined deficiencies of multiple steroid metabolizing enzymes. The P450 oxidoreductase deficiency (PORD) was first reported in patients with symptoms of defects in steroidogenic cytochrome P450 enzymes and ambiguous genitalia, and bone malformation features resembling Antley-Bixler syndrome. POR is now classified as a separate and rare form of congenital adrenal hyperplasia (CAH), which may cause disorder of sexual development (DSD). Since the initial description of PORD in 2004, a large number of POR mutations and polymorphisms have been described. In this report we have performed computational analysis of mutations and polymorphisms in POR linked to metabolism of steroids and xenobiotics and pathology of PORD from the reported cases. The mutations in POR that were identified in patients with disruption of steroidogenesis also have severe effects on cytochrome P450 proteins involved in metabolism of drugs. Different variations in POR show a range of diverse effects on different partner proteins that are often linked to the location of the particular variants. The variations in POR that cause defective binding of co-factors always have damaging effects on all partner proteins, while the mutations causing subtle structural changes may lead to altered interaction with partner proteins and the overall effect may be different for each individual partner. Computational analysis of available sequencing data and mutation analysis shows that Japanese (R457H), Caucasian (A287P) and Turkish (399-401) populations can be linked to unique founder mutations. Other mutations identified so far were identified as rare alleles or in single isolated reports. The common polymorphism of POR is the variant A503V which can be found in about 27% of alleles in general population but there are remarkable differences among different sub populations.

Long-term follow-up of a female with congenital adrenal hyperplasia due to P450-oxidoreductase deficiency

P450 oxidoreductase deficiency (PORD) is a variant of congenital adrenal hyperplasia that is caused by POR gene mutations. The POR gene encodes a flavor protein that transfers electrons from nicotinamide adenine dinucleotide phosphate (NADPH) to all microsomal cytochrome P450 type II (including 21-hydroxylase, 17α-hydroxylase 17,20 lyase and aromatase), which is fundamental for their enzymatic activity. POR mutations cause variable impairments in steroidogenic enzyme activities that result in wide phenotypic variability ranging from 46,XX or 46,XY disorders of sexual differentiation, glucocorticoid deficiency, with or without skeletal malformations similar to Antley-Bixler syndrome to asymptomatic newborns diagnosed during neonatal screening test. Little is known about the PORD long-term evolution. We described a 46,XX patient with mild atypical genitalia associated with severe bone malformation, who was diagnosed after 13 years due to sexual infantilism. She developed large ovarian cysts and late onset adrenal insufficiency during follow-up, both of each regressed after hormone replacement therapies. We also described a late surgical approach for the correction of facial hypoplasia in a POR patient.

Classic and non-classic 21-hydroxylase deficiency can be discriminated from P450 oxidoreductase deficiency in Japanese infants by urinary steroid metabolites

We previously reported a two-step biochemical diagnosis to discriminate classic 21-hydroxylase deficiency (C21OHD) from P450 oxidoreductase deficiency (PORD) by using urinary steroid metabolites: the pregnanetriolone/tetrahydrocortisone ratio (Ptl / the cortisol metabolites 5α- and 5β-tetrahydrocortisone (sum of these metabolites termed THEs), and 11β-hydroxyandrosterone (11OHAn). The objective of this study was to investigate whether both C21OHD and non-classic 21OHD (C+NC21OHD) could be biochemically differentiated from PORD. We recruited 55 infants with C21OHD, 8 with NC21OHD, 16 with PORD, 57 with transient hyper-17α-hydroxyprogesteronemia (TH17OHP), and 2,473 controls. All infants were Japanese with ages between 0-180 d. In addition to Ptl, THEs, and 11OHAn, we measured urinary tetrahydroaldosterone (THAldo) and pregnenediol (PD5). The first step: by Ptl with the age-specific cutoffs 0.06 mg/g creatinine (0-10 d of age) and 0.3 mg/g creatinine (11-180 d of age), we were able to differentiate C+NC21OHD and PORD from TH17OHP and controls (0-10 d of age: 0.065-31 vs. < 0.001-0.052, 11-180 d of age: 0.40-42 vs. < 0.001-0.086) with 100% sensitivity and specificity. The second step: by the 11OHAn/THAldo or 11OHAn/PD5 ratio with a cutoff of 0.80 or 1.0, we were able to discriminate between C+NC21OHD and PORD (1.0-720 vs. 0.021-0.61 or 1.8-160 vs. 0.005-0.32, respectively) with 100% sensitivity and specificity. Ptl, 11OHAn/THAldo, and 11OHAn/PD5 could differentiate between C+NC21OHD and PORD in Japanese infants.

Compound heterozygosity of a paternal submicroscopic deletion and a maternal missense mutation in POR gene: Antley-bixler syndrome phenotype in three sibling fetuses

BACKGROUND

Antley-Bixler syndrome (ABS) is an exceptionally rare craniosynostosis syndrome that can be accompanied by disordered steroidogenesis, and is mainly caused by mutations in the POR gene, inherited in an autosomal recessive manner. Here we report the prenatal and postmortem findings of three sibling fetuses with ABS as a result of compound heterozygosity of a paternal submicroscopic deletion and a maternal missense mutation in the POR gene.

METHODS

Prenatal ultrasound and postmortem examination were performed in three sibling fetuses with termination of pregnancy at 22, 23, and 17 weeks of gestation, respectively. Molecular analysis of fetus 2 and 3 included (a) bidirectional sequencing of exon 8 of the POR gene after amplification of the specific locus by polymerase chain reaction, to detect single nucleotide variants (SNVs) and (b) high resolution comparative genomic hybridization (CGH) positive single nucleotide polymorphism array CGH (aCGH) analysis to detect copy number variants (CNVs), copy neutral areas of loss of heterozygosity and uniparental disomy.

RESULTS

The diagnosis of ABS was suggested by the postmortem examination findings. The combination of the POR gene molecular analysis and aCGH revealed a compound heterozygous genotype of a maternal SNV (p.A287P) and a paternal CNV (NC_000007.13:g.(?_75608488)_(75615534_?)del).

CONCLUSION

To the best of our knowledge, these sibling fetuses add to the few reported cases of ABS, caused by a combination of a SNV and a CNV in the POR gene. The detailed description of the pathologic and radiographic findings of second trimester fetuses affected with ABS adds novel knowledge concerning the early ABS phenotype, in lack of previous relevant reports. Birth Defects Research (Part A) 106:536-541, 2016. © 2016 Wiley Periodicals, Inc.

Fertility Issues in Disorders of Sex Development

Fertility potential should be considered by the multidisciplinary team when addressing gender assignment, surgical management, and patient and family counselling of individuals with disorders of sex development. In 46,XY individuals, defects of gonadal differentiation or androgen or anti-Müllerian hormone synthesis or action result in incomplete or absent masculinization. In severe forms, raised as females, motherhood is possible with oocyte donation if Müllerian ducts have developed. In milder forms, raised as males, azoospermia or oligospermia are frequently found, however paternity has been reported. Most 46,XX patients with normal ovarian organogenesis are raised as females, and fertility might be possible after treatment.

A Genetic-Pathophysiological Framework for Craniosynostosis

Craniosynostosis, the premature fusion of one or more cranial sutures of the skull, provides a paradigm for investigating the interplay of genetic and environmental factors leading to malformation. Over the past 20 years molecular genetic techniques have provided a new approach to dissect the underlying causes; success has mostly come from investigation of clinical samples, and recent advances in high-throughput DNA sequencing have dramatically enhanced the study of the human as the preferred "model organism." In parallel, however, we need a pathogenetic classification to describe the pathways and processes that lead to cranial suture fusion. Given the prenatal onset of most craniosynostosis, investigation of mechanisms requires more conventional model organisms; principally the mouse, because of similarities in cranial suture development. We present a framework for classifying genetic causes of craniosynostosis based on current understanding of cranial suture biology and molecular and developmental pathogenesis. Of note, few pathologies result from complete loss of gene function. Instead, biochemical mechanisms involving haploinsufficiency, dominant gain-of-function and recessive hypomorphic mutations, and an unusual X-linked cellular interference process have all been implicated. Although few of the genes involved could have been predicted based on expression patterns alone (because the genes play much wider roles in embryonic development or cellular homeostasis), we argue that they fit into a limited number of functional modules active at different stages of cranial suture development. This provides a useful approach both when defining the potential role of new candidate genes in craniosynostosis and, potentially, for devising pharmacological approaches to therapy.

Guidelines for diagnosis and treatment of 21-hydroxylase deficiency (2014 revision)

Purpose of developing the guidelines: The first guidelines for diagnosis and treatment of 21-hydroxylase deficiency (21-OHD) were published as a diagnostic handbook in Japan in 1989, with a focus on patients with severe disease. The “Guidelines for Treatment of Congenital Adrenal Hyperplasia (21-Hydroxylase Deficiency) Found in Neonatal Mass Screening (1999 revision)” published in 1999 were revised to include 21-OHD patients with very mild or no clinical symptoms. Accumulation of cases and experience has subsequently improved diagnosis and treatment of the disease. Based on these findings, the Mass Screening Committee of the Japanese Society for Pediatric Endocrinology further revised the guidelines for diagnosis and treatment. Target disease/conditions: 21-hydroxylase deficiency. Users of the guidelines: Physician specialists in pediatric endocrinology, pediatric specialists, referring pediatric practitioners, general physicians; and patients.

Novel insight into etiology, diagnosis and management of primary adrenal insufficiency

Primary adrenal insufficiency (PAI) is a rare condition in childhood which is either inherited (mostly) or acquired. It is characterized by glucocorticoid and maybe mineralocorticoid deficiency. The most common form in children is 21-hydroxylase deficiency, which belongs to the steroid biosynthetic defects causing PAI. Newer forms of complex defects of steroid biosynthesis are P450 oxidoreductase deficiency and (apparent) cortisone reductase deficiency. Other forms of PAI include metabolic disorders, autoimmune disorders and adrenal dysgenesis, e.g. the IMAGe syndrome, for which the underlying genetic defect has been recently identified. Newer work has also expanded the genetic causes underlying isolated, familial glucocorticoid deficiency (FGD). Mild mutations of CYP11A1 or StAR have been identified in patients with FGD. MCM4 mutations were found in a variant of FGD in an Irish travelling community manifesting with PAI, short stature, microcephaly and recurrent infections. Finally, mutations in genes involved in the detoxification of reactive oxygen species were identified in patients with unsolved FGD. Most mutations were found in the enzyme nicotinamide nucleotide transhydrogenase, which uses the mitochondrial proton pump gradient to produce NADPH. NADPH is essential in maintaining high levels of reduced forms of antioxidant enzymes for the reduction of hydrogen peroxide. Similarly, mutations in the gene for TXNRD2 involved in this system were found in FGD patients, suggesting that the adrenal cortex is particularly susceptible to oxidative stress.

Clinical and molecular review of atypical congenital adrenal hyperplasia

Congenital adrenal hyperplasia (CAH) is one of the most common inherited metabolic disorders. It comprises a group of autosomal recessive disorders caused by the mutations in the genes encoding for steroidogenic enzymes that involved cortisol synthesis. More than 90% of cases are caused by a defect in the enzyme 21-hydroxylase. Four other enzyme deficiencies (cholesterol side-chain cleavage, 17α-hydroxylase [P450c17], 11β-hydroxylase [P450c11β], 3β-hydroxysteroid dehydrogenase) in the steroid biosynthesis pathway, along with one cholesterol transport protein defect (steroidogenic acute regulatory protein), and one electrontransfer protein (P450 oxidoreductase) account for the remaining cases. The clinical symptoms of the different forms of CAH result from the particular hormones that are deficient and those that are produced in excess. A characteristic feature of CAH is genital ambiguity or disordered sex development, and most variants are associated with glucocorticoid deficiency. However, in the rare forms of CAH other than 21-hydroxylase deficiency so-called "atypical CAH", the clinical and hormonal phenotypes can be more complicated, and are not well recognized. This review will focus on the atypical forms of CAH, including the genetic analyses, and phenotypic correlates.

Cytochrome P450 oxidoreductase deficiency: rare congenital disorder leading to skeletal malformations and steroidogenic defects

Cytochrome P450 oxidoreductase (POR) deficiency (PORD) is a newly characterized disorder. PORD is caused by homozygous or compound heterozygous mutations in POR encoding an electron donor for several microsomal enzymes such as CYP21A2, CYP17A1, CYP19A1, CYP51A1, and CYP26A1-C1. Molecular defects of PORD include a Japanese founder mutation p.R457H, as well as various missense, nonsense, frameshift, and splice-site mutations and exonic deletions. PORD leads to unique skeletal malformations referred to as Antley-Bixler syndrome, in addition to 46,XX and 46,XY disorders of sex development, pubertal failure, adrenal dysfunction, and maternal virilization during pregnancy. Such clinical features are ascribable to impaired activities of the POR-dependent microsomal enzymes. PORD represents one form of congenital adrenal hyperplasia, although it can occur as a congenital malformation syndrome and a disorder of sex development. Phenotypic severity of PORD is highly variable and only partly depends on the residual activity of the mutant proteins. It is possible that PORD remains undiagnosed in several patients. Detailed hormonal assessment and molecular analysis are useful for diagnosis of PORD.

Differentiation of mesenchymal stem cells into gonad and adrenal steroidogenic cells

Hormone replacement therapy is necessary for patients with adrenal and gonadal failure. Steroid hormone treatment is also employed in aging people for sex hormone deficiency. These patients undergo such therapies, which have associated risks, for their entire life. Stem cells represent an innovative tool for tissue regeneration and the possibility of solving these problems. Among various stem cell types, mesenchymal stem cells have the potential to differentiate into steroidogenic cells both in vivo and in vitro. In particular, they can effectively be differentiated into steroidogenic cells by expressing nuclear receptor 5A subfamily proteins (steroidogenic factor-1 and liver receptor homolog-1) with the aid of cAMP. This approach will provide a source of cells for future regenerative medicine for the treatment of diseases caused by steroidogenesis deficiencies. It can also represent a useful tool for studying the molecular mechanisms of steroidogenesis and its related diseases.

Prenatal diagnosis of congenital adrenal hyperplasia caused by P450 oxidoreductase deficiency

CONTEXT

Mutations in the electron donor enzyme P450 oxidoreductase (POR) result in congenital adrenal hyperplasia with apparent combined 17α-hydroxylase/17,20 lyase and 21-hydroxylase deficiencies, also termed P450 oxidoreductase deficiency (PORD). Major clinical features present in PORD are disordered sex development in affected individuals of both sexes, glucocorticoid deficiency, and multiple skeletal malformations.

OBJECTIVE

The objective of the study was to establish a noninvasive approach to prenatal diagnosis of PORD including assessment of malformation severity to facilitate optimized prenatal diagnosis and timely treatment.

DESIGN

We analyzed 20 pregnancies with children homozygous or compound heterozygous for disease-causing POR mutations and 1 pregnancy with a child carrying a heterozygous POR mutation by recording clinical and biochemical presentations and fetal ultrasound findings. In 4 of the pregnancies (3 homozygous and 1 heterozygous for disease-causing POR mutations), prenatal analysis of steroid metabolite excretion in maternal urine was carried out by gas chromatography/mass spectrometry during gestational weeks 11-23.

RESULTS

Pregnancy complications in our cohort included maternal virilization (6 of 20) with onset in the second trimester. Seven pregnant women presented with low unconjugated estriol at prenatal screening (triple or quadruple antenatal screening test). Overt dysmorphic features were noted in 19 of the 20 babies at birth but observed in only 5 by prenatal ultrasound. These 5 had the most severe malformation phenotypes and poor outcome, whereas the other babies showed normal development. Steroid profiling of maternal urine revealed significantly increased steroids of fetal origin, namely the pregnenolone metabolite epiallopregnanediol and the androgen metabolite androsterone, with concomitant low values for estriol. Diagnostic steroid ratios conclusively indicated PORD as early as gestational week 12. In the heterozygous pregnancy, steroid ratios were only slightly elevated and estriol excretion was normal.

CONCLUSION

Prenatal diagnosis in PORD is readily established via urinary steroid metabolite analysis of maternal urine. Visible malformations at prenatal ultrasound predict a severe malformation phenotype.

NADPH P450 oxidoreductase: structure, function, and pathology of diseases

Cytochrome P450 oxidoreductase (POR) is an enzyme that is essential for multiple metabolic processes, chiefly among them are reactions catalyzed by cytochrome P450 proteins for metabolism of steroid hormones, drugs and xenobiotics. Mutations in POR cause a complex set of disorders that often resemble defects in steroid metabolizing enzymes 17α-hydroxylase, 21-hydroxylase and aromatase. Since our initial reports of POR mutations in 2004, more than 200 different mutations and polymorphisms in POR gene have been identified. Several missense variations in POR have been tested for their effect on activities of multiple steroid and drug metabolizing P450 proteins. Mutations in POR may have variable effects on different P450 partner proteins depending on the location of the mutation. The POR mutations that disrupt the binding of co-factors have negative impact on all partner proteins, while mutations causing subtle structural changes may lead to altered interaction with specific partner proteins and the overall effect may be different for each partner. This review summarizes the recent discoveries related to mutations and polymorphisms in POR and discusses these mutations in the context of historical developments in the discovery and characterization of POR as an electron transfer protein. The review is focused on the structural, enzymatic and clinical implications of the mutations linked to newly identified disorders in humans, now categorized as POR deficiency.

NADPH-cytochrome P450 oxidoreductase: roles in physiology, pharmacology, and toxicology

This is a report on a symposium sponsored by the American Society for Pharmacology and Experimental Therapeutics and held at the Experimental Biology 2012 meeting in San Diego, California, on April 25, 2012. The symposium speakers summarized and critically evaluated our current understanding of the physiologic, pharmacological, and toxicological roles of NADPH-cytochrome P450 oxidoreductase (POR), a flavoprotein involved in electron transfer to microsomal cytochromes P450 (P450), cytochrome b(5), squalene mono-oxygenase, and heme oxygenase. Considerable insight has been derived from the development and characterization of mouse models with conditional Por deletion in particular tissues or partial suppression of POR expression in all tissues. Additional mouse models with global or conditional hepatic deletion of cytochrome b(5) are helping to clarify the P450 isoform- and substrate-specific influences of cytochrome b(5) on P450 electron transfer and catalytic function. This symposium also considered studies using siRNA to suppress POR expression in a hepatoma cell-culture model to explore the basis of the hepatic lipidosis phenotype observed in mice with conditional deletion of Por in liver. The symposium concluded with a strong translational perspective, relating the basic science of human POR structure and function to the impacts of POR genetic variation on human drug and steroid metabolism.

Two-Step Biochemical Differential Diagnosis of Classic 21-Hydroxylase Deficiency and Cytochrome P450 Oxidoreductase Deficiency in Japanese Infants by GC-MS Measurement of Urinary Pregnanetriolone/ Tetrahydroxycortisone Ratio and 11β-Hydroxyandrosterone

BACKGROUND

The clinical differential diagnosis of classic 21-hydroxylase deficiency (C21OHD) and cytochrome P450 oxidoreductase deficiency (PORD) is sometimes difficult, because both deficiencies can have similar phenotypes and high blood concentrations of 17α-hydroxyprogesterone (17OHP). The objective of this study was to identify biochemical markers for the differential diagnosis of C21OHD, PORD, and transient hyper 17α-hydroxyprogesteronemia (TH17OHP) in Japanese newborns. We established a 2-step biochemical differential diagnosis of C21OHD and PORD.

METHODS

We recruited 29 infants with C21OHD, 9 with PORD, and 67 with TH17OHP, and 1341 control infants. All were Japanese and between 0 and 180 days old; none received glucocorticoid treatment before urine sampling. We measured urinary pregnanetriolone (Ptl), the cortisol metabolites 5α- and 5β-tetrahydrocortisone (sum of these metabolites termed THEs), and metabolites of 3 steroids, namely dehydroepiandrosterone, androstenedione (AD4), and 11β-hydroxyandrostenedione (11OHAD4) by GC-MS.

RESULTS

At a cutoff of 0.020, the ratio of Ptl to THEs differentiated C21OHD and PORD from TH17OHP and controls with no overlap. Among metabolites of DHEA, AD4, and 11OHAD4, only 11β-hydroxyandrosterone (11HA), a metabolite of 11OHAD4, showed no overlap between C21OHD and PORD at a cutoff of 0.35 mg/g creatinine.

CONCLUSIONS

A specific cutoff for the ratio of Ptl to THEs can differentiate C21OHD and PORD from TH17OHP and controls. Additionally, the use of a specific cutoff of 11HA can distinguish between C21OHD and PORD.