Diagnostic accuracy of human chorionic gonadotropins (HCG) stimulation test in XY-disorders of sex development (XY-DSD) presented in Armed Forces Institute of Pathology

OBJECTIVE

To determine diagnostic accuracy of human chorionic gonadotropins stimulation test in differentiating androgen insensitivity syndrome and 5-alpha reductase deficiency, keeping testosterone to dihydrotestosterone ratio as the gold standard.

METHODS

The cross-sectional study was conducted at the Department of Chemical Pathology and Endocrinology, Armed Forces Institute of Pathology, Rawalpindi, Pakistan, from January to December, 2016, and comprised patients aged 01 day to 20 years having XY chromosomes on karyotyping and with a spectrum of phenotypes. Blood samples were collected from each subject for basal serum testosterone, serum luteinizing hormone and serum follicular stimulating hormone level. Human chorionic gonadotropins stimulation test was performed in every subject as per the protocol. Sandwich chemiluminescence immunoassay technique was used to analyse serum samples. Serum dihydrotestosterone level was also detected to determine testosterone and dihydrotestosterone ratio. Data was analysed using SPSS 24. .

RESULTS

Of the 104 subjects with a mean age of 1.78}0.95 years,96(92.3%) were diagnosed as cases of androgen insensitivity syndrome on the basis of human chorionic gonadotropins stimulation response level, which was 2-9 times of basal serum testosterone level. Also, 8(7.7%) subjects were diagnosed to have 5-alpha reductase deficiency syndrome. In such subjects, post-human chorionic gonadotropins response level of serum testosterone was more than 10 times of the basal level.

CONCLUSIONS

The human chorionic gonadotropins stimulation test was found to be comparable to testosterone-to dihydrotestosterone ratio in differentiating between case of androgen insensitivity syndrome and 5-alpha reductase deficiency.

Establishing reproductive potential and advances in fertility preservation techniques for XY individuals with differences in sex development

BACKGROUND

Discordance between gonadal type and gender identity has often led to an assumption of infertility in patients with differences in sex development (DSD). However, there is now greater recognition of fertility being an important issue for this group of patients. Currently, gonadal tissue that may have fertility potential is not being stored for individuals with DSD and, where gonadectomy forms part of management, is often discarded. The area of fertility preservation has been predominantly driven by oncofertility which is a field dedicated to preserving the fertility of patients undergoing gonadotoxic cancer treatment. The use of fertility preservation techniques could be expanded to include individuals with DSD where functioning gonads are present.

METHODS

This is a systematic literature review evaluating original research articles and relevant reviews between 1974 and 2018 addressing DSD and fertility, in vitro maturation of sperm, and histological/ultrastructural assessment of gonadal tissue in complete and partial androgen insensitivity syndrome, 17β-hydroxysteroid dehydrogenase type 3 and 5α-reductase deficiency.

CONCLUSION

Successful clinical outcomes of ovarian tissue cryopreservation are paving the way for similar research being conducted using testicular tissue and sperm. There have been promising results from both animal and human studies leading to cryopreservation of testicular tissue now being offered to boys prior to cancer treatment. Although data are limited, there is evidence to suggest the presence of reproductive potential in the gonads of some individuals with DSD. Larger, more detailed studies are required, but if these continue to be encouraging, individuals with DSD should be given the same information, opportunities and access to fertility preservation as other patient groups.

Disorders Of Sex Differentiation: Evaluation And Management, A Dilemma

The term intersex used in the past has been replaced by "Disorders of Sex Differentiation". In this condition the development of chromosomal, gonadal or anatomical sex is atypical. This problem creates anxiety to the parents and a challenge for attending doctor. The problems faced by the individual are sexual, reproductive, sex of raring, placement in the society and psychological impact. The optimal management of the patient should be individualized by multidisciplinary team. Three cases of Disorders of Sex Differentiation (DSD) are presented with different causes and presentations. Two cases carrying XY karyotype pattern, while one case was of XX. The diagnosis of swyers syndrome, 5 alpha reductase deficiency and congenital adrenal hyperplasia was made on the basis of genital tract development, hormonal analysis and karyotyping. The strange feature which was common in all these cases was the wish of patients as well as family members to adopt sex of raring as male.

Initial assessment of a child with suspected disorder of sex development

Disorders of sex development (DSD) are defined as discrepancy between chromosomal, gonadal and anatomic sex. The basic principles for the management of DSD include a multidisciplinary approach for gender assignment. Clinical assessment includes a detailed history and examination of external genitalia. Most of the disorders with symmetrical gonades indicate hormonal cause while asymmetrical gonades are found in chromosomal DSDs. Karyotyping will indicate a 46XX DSD, 46 XY DSD or mosicism. Internal anatomy is defined by ultrasonography, genitoscopy and laparoscopy. Human chorionic gonadotrophins (hCG) stimulation test is carried out in under-virilised males to see the function of Leydig cells in testes. The Most common cause of 46XX DSD is congenital adrenal hyperplasia (CAH). The decision of gender assignment surgery is to be taken in a multidisciplinary environment and with informed consent of the parents. Most of 46 XX CAH patients, even if markedly virilised, and 46 XY complete androgen insensitivity syndrome are raised as females. Similarly, most of 5-α reductase deficiency and 17-β hydroxysteroid dehydrogenase deficiency patients are assigned to the male gender. The decision in cases of mixed gondal dysgenesis and ovotesticular DSD is based on the development of external and internal genitalia. Patients with androgen biosynthetic defects, partial androgen insensitivity syndrome are usually assigned to the male gender.

Persistent Mullerian Duct Syndrome with Polysplenia and Short Pancreas: A Case Report

Persistent Mullerian duct syndrome is a rare entity and usually presents with common symptoms of undescended testis and hernia. The syndrome is caused by an insufficient amount of Mullerian inhibiting substance or due to the insensitivity of the target organ to Mullerian inhibiting substance. Polysplenia is a rare congenital disease manifested by multiple small accessory spleens. The association of these two entities, Persistent Mullerian duct syndrome and polysplenia, is rare and has not been reported in the literature. We reported a case of a 27 years old male presented with complains of right flank pain and nausea. Ultrasound showed right ureteric calculus with hydronephrosis and elongated soft tissue mass posterior to bladder. Contrast enhanced Computed Tomography showed soft tissue suggestive of infantile uterine structure with multiple splenculi and short pancreas. He was diagnosed as Persistent Mullerian duct syndrome with unilateral cryptorchidism, polysplenia and short pancreas, coincidentally detected while evaluating for ureteric colic. He underwent Ureteroscopic Lithotripsy with stenting for ureteric calculus, however, he refused laparotomy with excision of mullerian structures.

Long-term follow-up in a Chinese child with congenital lipoid adrenal hyperplasia due to a StAR gene mutation

BACKGROUND

Congenital lipoid adrenal hyperplasia (CLAH) is an extremely rare and the most severe form of congenital adrenal hyperplasia. Typical features include disorder of sex development, early-onset adrenal crisis and enlarged adrenal glands with fatty accumulation.

CASE PRESENTATION

We report a case of CLAH caused by mutations in the steroidogenic acute regulatory protein (StAR) gene. The patient had typical early-onset adrenal crisis at 2 months of age. She had normal-appearing female genitalia and a karyotype of 46, XY. The serum cortisol and adrenal steroids levels were always nearly undetectable, but the adrenocorticotropic hormone levels were extremely high. Genetic analysis revealed compound heterozygous mutations at c. 229C > T (p.Q77X) in exon 3 and c. 722C > T (p.Q258X) in exon 7 of the StAR gene. The former mutation was previously detected in only two other Chinese CLAH patients. Both mutations cause truncation of the StAR protein. The case reported here appears to be a classic example of CLAH with very small adrenal glands and is the second reported CLAH case with small adrenal glands thus far. In a 15-year follow-up, the patient's height was approximately average for females before age 4 and fell to - 1 SDS at 10 years of age. Her bone age was similar to her chronological age from age 4 to age 15 years.

CONCLUSIONS

In conclusion, this is a classic case of CLAH with exceptionally small adrenal glands. Q77X mutation seems to be more common in Chinese CLAH patients. Additionally, this is the first report of the growth pattern associated with CLAH after a 15-year follow-up.

[A rare cause of cryptorchidism, the persistence of müllerian ducts syndrome]

The Persistent Müllerian Ducts Syndrome (PMDS) is a rare congenital syndrome. It is one of abnormalities of genito-sexual development that is found on the normally virilized boy (46XY). It is characterized by the development of both Wolf structures and Müller duct. The pathophysiology can be explained by an action deficit of the anti-müllerian hormone (AMH). Its clinical presentations vary depending on the localization of the testis and the associated symptoms. Its discovery is mostly fortuitous and generally made in per-operative surgery of cryptorchidism or inguinal hernia. Treatment should be surgical. It relies on two aspects : ensuring the testicular descent and performing the excision of the müllerian duct. The follow-up is identical to the cryptorchid testes and the fertility problems will be influenced by the surgical procedure as well as the timing of the treatment.

Clinical and molecular characterization of 5α-reductase type 2 deficiency due to mutations (p.Q6X, p.R246Q) in SRD5A2 gene

Early diagnosis and optimal management for steroid 5α-reductase type 2 deficiency (5α-RD2) patients are major challenges for clinicians and mutation analysis for the 5α-reductase type 2 (SRD5A2) gene is the golden standard for the diagnosis of the disease. In silico analysis of this enzyme has not been reported due to the lack of appropriate model. Moreover, the histological and pathological changes of the gonads are largely unknown. In the present study, a 5α-RD2 patient born with abnormal external genitalia was studied and mutation analysis for SRD5A2 gene was conducted. Moreover, we constructed the homology modeling of 5α-reductase using SWISS-MODEL, followed by the molecular docking study. Furthermore, immunohistochemical staining of Ki67 for the testes tissue was conducted to investigate the potential pathological characteristics. The patient had male (46, XY) chromosomes but presented female characteristics, and the mutation analysis identified a heterozygotes mutation (p.Q6X, p.R246Q) in SRD5A2 gene. In silico analysis elucidated the potential effect of the mutation on enzyme activity. Immunohistochemical staining for the excised testes showed that 30%-50% of the germ cells were Ki67 positive, which indicated the early neoplastic potential. In conclusion, we analyzed the genotype-phenotype correlations of 5α-RD2 caused by a heterozygotes mutation (p.Q6X, p.R246Q). Importantly, we conducted the homology modeling and molecular docking for the first time, which provided a homology model for further investigations. Immunohistochemical results suggested gonadectomy or testis descent should be performed early for 5α-RD2 patient, as delayed treatment would have maintained the testes in a tumorigenic condition.

A case report of pedigree of a homozygous mutation of the steroidogenic acute regulatory protein causing lipoid congenital adrenal hyperplasia

RATIONALE

Lipoid congenital adrenal hyperplasia (LCAH) is extremely rare, but is the most fatal form of congenital adrenal hyperplasia resulting from mutations in the steroidogenic acute regulatory protein (STAR) gene. LCAH arises from severe defects in the conversion of cholesterol to pregnenolone, the precursor of all steroids.

PATIENT CONCERNS

A case was reported that an 11-month-old Chinese girl who presented with a sex development disorder and hyponatremia. The clinical and genetic tests were carried out to confirm the diagnosis. The genogram of this case was also explored and analyzed. The girl presented with hyponatremia, decreased cortisol level, elevated adrenocorticotropic hormone level and female vulva despite a 46, XY karyotype. Enlarged adrenal glands and testicular-like tissue in the bilateral inguinal regions were detected with abdominal ultrasound. She was suspected of having LCAH, and definitive diagnosis was made after Sanger sequencing detected a homozygous frameshift variant c.707_708delins CTT (p.Lys236Thrfs*47) on exon 6 of the STAR gene.

DIAGNOSES

LCAH.

INTERVENTIONS

She was prescribed hydrocortisone 10 to 12 mg/m2 and 9a- fludrocortisone 100 mg/d.

OUTCOMES

Her skin hyperpigmentation and vomiting disappeared, and she had normal growth and development without adrenal crisis attacks. Her hormone and electrolyte levels remained normal, except for a persistently elevated ACTH level throughout 2 years of follow-up. At follow-up for 2 years, the patient is now 104.5 cm tall and weighs 23.3 kg at the age of 4 years old. Her plasma sodium and potassium concentration were normal. Her ACTH level is still elevated (1176 pg/mL). Her baseline sex hormone levels are testosterone <0.1 ng/dL and progesterone <0.08 ng/dL. The level of PRA (1.06 ng/mL per h) is within normal range.

LESSONS

This mutation was in accordance with previously reported gene mutations. The patient's parents were nonconsanguineous; her parents, paternal grandfather, and maternal grandmother were all found to be carriers of a STAR gene mutation. This 46 XY disorders of sex development case presented with adrenal insufficiency and female phenotype initially. The diagnosis was complicated depending on the clinical hormone workup. LCAH was confirmed by genetic tests and genogram of the family.

Persistent Müllerian duct syndrome: A novel mutation in the Αnti-Müllerian Ηormone gene

BACKGROUND AND OBJECTIVE

Persistent Müllerian duct syndrome (PMDS) is a relatively rare form of 46,XY disorder of sex development caused by the failure of formation, release or action of anti-Müllerian hormone (AMH) in intrauterine life. In this report we describe a case diagnosed with PMDS with a novel homozygous mutation in the AMH gene.

CASE REPORT

A 4-month-old male presented with bilateral cryptorchidism and normal external genitalia. The laboratory examination revealed normal gonadotropin levels for his age (FSH: 0.91 mIU/mL, LH: 1.23 mIU/mL, testosteron <0.13 ng/mL, respectively). AMH was undetectable (<0.01 ng/mL). Ultrasonography (USG) revealed absence of the left gonad and an intraabdominally located right gonad. Laparoscopy demonstrated the presence of a rudimentary uterus and fallopian tubes. Karyotyping revealed a normal 46,XY karyotype. Molecular genetic analysis demonstrated a novel homozygous mutation [p.C526F (c.1577G>T)] in the AMH gene.

CONCLUSION

PMDS should be kept in mind in all cases with bilateral crytorchidism. Orchidopexy and resection of Mulletian duct derivates, exercising extra caution with regard to maintaining vascular supply to the testis, is the recommended approach.

The Long-Term Outcome of Boys With Partial Androgen Insensitivity Syndrome and a Mutation in the Androgen Receptor Gene

BACKGROUND

In boys with suspected partial androgen insensitivity syndrome (PAIS), systematic evidence that supports the long-term prognostic value of identifying a mutation in the androgen receptor gene (AR) is lacking.

OBJECTIVE

To assess the clinical characteristics and long-term outcomes in young men with suspected PAIS in relation to the results of AR analysis.

METHODS

Through the International Disorders of Sex Development Registry, clinical information was gathered on young men suspected of having PAIS (n = 52) who presented before the age of 16 years and had genetic analysis of AR.

RESULTS

The median ages at presentation and at the time of the study were 1 month (range, 1 day to 16 years) and 22 years (range, 16 to 52 years), respectively. Of the cohort, 29 men (56%) had 20 different AR mutations reported. At diagnosis, the median external masculinization scores were 7 and 6 in cases with and without AR mutation, respectively (P = .9), and median current external masculinization scores were 9 and 10, respectively (P = .28). Thirty-five men (67%) required at least one surgical procedure, and those with a mutation were more likely to require multiple surgeries for hypospadias (P = .004). All cases with an AR mutation had gynecomastia, compared to 9% of those without an AR mutation. Of the six men who had a mastectomy, five (83%) had an AR mutation.

CONCLUSIONS

Boys with genetically confirmed PAIS are likely to have a poorer clinical outcome than those with XY DSD, with normal T synthesis, and without an identifiable AR mutation. Routine genetic analysis of AR to confirm PAIS informs long-term prognosis and management.

[Advances in the diagnosis and hormone replacement treatment of 46, XY disorders of sex development]

Disorders of sex development (DSD) is defined as a congenital condition or atypical development of the chromosomal, gonadal, or anatomic sex. The diagnosis, gender assignment, and treatment of DSD require the guidance from experienced multidisciplinary teams. So far there has been no consensus about it in China. Due to dysgenetic gonads, defects in sex steroid biosynthesis or action, or gonadectomy during the prepubertal years, those with DSD suffer from hypogonadism. The hormone replacement therapy of DSD aims at general physiological health and long-term prognosis as well as the avoidance of unnecessary genital and gonadal surgery. This review focuses on the advances in the studies of the diagnosis and hormone replacement therapy of 46,XY DSD.

Persistent Müllerian Duct Syndrome Caused by a Novel Mutation of an Anti-MüIlerian Hormone Receptor Gene: Case Presentation and Literature Review

Persistent Müllerian duct syndrome (PMDS) is a rare genetic disorder of male internal sexual development defined as lack of regression of Müllerian derivatives in the 46XY male with normally virilized external genitalia and unilateral or bilateral cryptorchidism. Approximately 85% of all cases are caused by mutations in genes encoding anti-Müllerian hormone (AMH) or its receptor (AMHR2) with autosomal recessive transmission. This condition is frequently diagnosed incidentally, during surgical repair of inguinal hernia or cryptorchidism. There is no consensus on surgical approach: malignancy risk in the Müllerian duct remnant or undescended testis encourages early removal of the former and bilateral orchiopexy; however, removal of Müllerian structures can impair testicular and vas deferens blood supply, potentially causing infertility. Herein, we report on a male infant with PMDS caused by a novel homozygous missense mutation in AMHR2 (c.928C>T; p.Q310X), review the literature, and discuss the diverse clinical and surgical approaches to this condition.

Delayed diagnosis of disorder of sex development (DSD) due to P450 oxidoreductase (POR) deficiency

CASE PRESENTATION

A 36-year old man, operated on for cryptorchidism at the age of 8 years, was referred to the Outpatient Clinic of Reproductive Endocrinology for investigation of infertility. Clinical examination revealed ambiguous genitalia: penis 4-5 cm, testicular volume 2-3 ml, hypospadias, hypertrophic foreskin and scrotum bifida. Mild hypertension was confirmed. No skeletal malformations were detected.

DESIGN

Hormonal and electrolytic determinations as well as semen analysis were conducted. PCR of the coding regions of 17-hydroxylase/17,20 lyase (P450c17) and of P450 oxidoreductase (POR) genes was also performed.

RESULTS

Normal levels of electrolytes, low levels of androgens, high levels of gonadotropins and 17-hydroxyprogesterone as well as azoospermia were detected. Karyotype was shown to be 46,XY. Both hCG and ACTH stimulation significantly increased 17-hydroxyprogesterone with no increase in androgens. The diagnosis was congenital adrenal hyperplasia with apparent combined P450c17 and P450c21 deficiency due to mutations in the POR gene. Sequencing of the POR gene revealed: one deletion in exon 12 (Del 1696_1698delGTC >del531Valine) and one missense mutation in exon 7 (A259G) as well as two polymorphisms: rs1057868 (C/T A503V) and rs1057870 (G/A S572S) in exons 12 and 13, respectively. No nucleotide changes were detected in the 8 exons of P450c17.

CONCLUSIONS

Molecular findings were consistent with the diagnosis of P450 oxidoreductase deficiency. Despite this severe deficiency, skeletal malformations simulating Antley-Bixler syndrome, which usually characterize the most severe forms, were not confirmed. This discrepancy could be attributed to the differential impact of a POR variant on each one of the P450 enzymes.

Identification of five novel STAR variants in ten Chinese patients with congenital lipoid adrenal hyperplasia

Congenital lipoid adrenal hyperplasia (CLAH) is a rare autosomal recessive disorder caused by defective synthesis of all steroids. This disorder is characterized by 46,XY sex reversal, skin hyperpigmentation, early-onset adrenal crisis and enlarged adrenal with fatty accumulation. CLAH is caused by mutations in the STAR gene. The clinical features and STAR gene mutation spectrum of a large cohort of Chinese patients with CLAH were not reported previously. We performed clinical retrospective review and genetic analysis of the STAR gene in ten unrelated Chinese phenotypic female patients who were clinically diagnosed with CLAH and followed up in our hospital from 2006 to 2015. All ten patients, including two 46,XY females and eight 46,XX females, presented skin hyperpigmentation and early salt-wasting episode, and showed normal growth and development after steroid replacement treatment. Totally 20 mutant alleles containing 11 different STAR gene mutations were identified in these ten patients, including five novel variants (two missense and three null variants), all predicted to be pathogenic in bioinformatics analysis, and six mutations described in previous literature. Among these 11 mutations, a reported mutation c.772C>T and a novel variant c.707_708delinsCTT were most frequent, accounting for 35% and 15% of the total mutant alleles, respectively. This is the first report of a large Chinese cohort with CLAH, presenting the mutation spectrum of the STAR gene and two possible founder mutations in the Chinese population, which may contribute to better genetic counseling and prenatal diagnosis.

Phenotype and molecular characteristics in 45 Chinese children with 5α-reductase type 2 deficiency from South China

CONTEXT

Affected by steroid 5α-reductase type 2 deficiency (5α-RD2), 46, XY individuals present divergent phenotypes characterized by undervirilization of male external genitalia. To identify the disorder, mutational analysis of 5α-reductase type 2 gene (SRD5A2) is a reliable approach. The genotype-phenotype relationship has not been elucidated.

OBJECTIVE

To improve the diagnosis and expand the knowledge of the disease, we collected and analysed relevant data of clinical diagnosis, biological investigation and molecular determination in 45 children with the SRD5A2 gene mutations from South China in our centre.

SUBJECTS AND METHODS

We studied a cohort of 45 Chinese children with SRD5A2 gene mutations.

RESULTS

Isolated microphallus (35·6%) and microphallus associated with various degrees of hypospadias (55·6%) were frequent phenotype. Female external genitalia with clitoromegaly (8·9%) were rare. 16 of 18 (88·9%) cases had hCG-stimulated T/DHT ratio above 10. In 45 patients, we identified 15 different mutations. Five have never been described: p.His90ThrfsX31, p.Gly21Arg, p.Gly149Asp, p.Arg145Leu and p.Gly66Arg. The p.Arg227Gln mutation was detected in 41 (91·1%) patients. The p.Leu89Val polymorphism was found in 38 (84·4%) patients. Homozygous mutations were presented in 16 (35·6%) patients, compound heterozygous mutations in 20 (44·4%) patients, compound heterozygous mutations alone with the p.Leu89Val polymorphism in nine (20·0%) patients. Exons 1 and 4 were most affected, and the number of mutant alleles per exon was 78·1% and 12·2%, respectively.

CONCLUSIONS

The study demonstrated a wide spectrum of phenotypes, biological profiles and genotypes in the children with 5α-RD2 from South China. The heterozygous mutation p.Arg227Gln is presumably a hot spot mutation and suggests a founder effect in the population of South China that may explain a moderate phenotype among our patients. Our report provides new insights into the molecular mechanism of 5α-RD2 and help to the diagnosis and treatment of this disease.

The spectrum of 46XY disorders of sex development in a University centre in Saudi Arabia

BACKGROUND

The term disorders of sex development (DSD) includes congenital conditions in which development of chromosomal, gonadal, or anatomical sex is atypical. The spectrum of the 46XY (DSD) is so broad. In this study, we reviewed the clinical spectrum of a cohort of patients with 46XY DSD in a tertiary institute in the Middle East over two decades.

OBJECTIVE

To define the clinical spectrum of 46XY DSD in a major teaching hospital, Riyadh, Saudi Arabia.

MATERIALS AND METHODS

This is a retrospective, case series hospital-based study. The case notes, laboratory investigations, and imaging studies were reviewed for patients with 46XY DSD over a 20 years period (1989-2010) at King Khalid University Hospital, Riyadh, Saudi Arabia. Molecular genetics were not available in all patients.

RESULTS

During the period under review; a total of 56 patients were seen with 46XY DSD due to variable etiologies. Androgen insensitivity syndromes (AIS) and 5-α-reductase deficiency were among the commonest (44.6%), with multiple siblings involvement within the family. Of these, 16 patients were showing variable degrees of insensitivity ranging between complete (n=5, 31.2%) and partial (n=11, 68.8%) insensitivity, whereas in nine patients the diagnosis of 5-α-reductase deficiency was entertained based on hormonal studies. Of interest to see was a high number of patients (n=14, 25%) either with a localized congenital anomalies such as the cloacal anomalies or generalized congenital malformations following the pattern of certain syndromes.

CONCLUSION

A wide spectrum of causes were noted. Androgen insensitivity syndrome was the commonest. In Saudi Arabia, where consanguineous mating is high, 5-α-reductase is also a common cause of 46XY DSD.

Pitfalls in hormonal diagnosis of 17-beta hydroxysteroid dehydrogenase III deficiency

Steroid 17β-hydroxysteroid dehydrogenase III (17β-HSD3) deficiency is a rare autosomal recessive disorder that usually presents in patients with a 46,XY karyotype with ambiguous genitalia at birth. The 17β-HSD3 enzyme, which is encoded by the HSD17B3 gene, converts gonadal delta-4 androstenedione (Δ4) to testosterone (T). Such 17β-HSD3 enzyme deficiency is expected to lead to an increased ratio of D4 to T when the patient undergoes a human chorionic gonadotropin stimulation (hCG) test. Two patients with 46,XY disorders of sexual differentiation were studied. Serum D4 and T levels were measured by HPLC tandem mass spectrometry. As one of the patients was born to consanguineous parents, we performed single nucleotide polymorphism (SNP) microarray to analyze regions of homozygosity (ROH). The HSD17B3 gene was sequenced using the Sanger method. Contrary to expectations, both patients demonstrated decreased D4/T ratio after hCG stimulation. Initial sequencing results for the androgen receptor or 5α-reductase were negative for mutations. ROH analysis identified HSD17B3 as a candidate gene that might cause the disease. Sanger sequencing of the HSD17B3 gene confirmed 17β-HSD3 deficiency in both patients. Serum D4/T ratios are not reliable parameters for the diagnosis of 17β-HSD3 deficiency. Molecular genetic analysis provides accurate diagnosis.

[Clinical features and StAR gene mutations in children with congenital lipoid adrenal hyperplasia]

This article reported the clinical manifestations, steroid profiles and adrenal ultrasound findings in two unrelated Chinese girls with lipoid congenital adrenal hyperplasia (LCAH). Direct DNA sequencing and restriction fragment length polymorphism (RFLP) analysis were used to identify the mutations of steroidogenic acute regulatory protein (StAR) gene. The two patients with 46,XX karyotype, presented hyperpigmentation, growth retardation, and hyponatremia. Steroid profiles analysis revealed elevated plasma adrenocorticotrophic hormone levels, decreased or normal serum cortisol levels and low levels of androgens. Ultrasound examinations revealed that enlarged adrenals in patient 1 and normal adrenals in patient 2. Direct DNA sequencing of StAR gene showed a reported homozygous for c.772C>T(p.Q258X) in patient 1. Compound heterozygous for c.367G>A(p.E123K) and IVS4+2T>A (both novel mutations) were found in patient 2, inherited from her mother and father respectively. The amino acid of mutant position of the novel p.E123K was highly conserved in ten different species and was predicted to have impacts on the structure and function of StAR protein by the PolyPhen-2 prediction software. RFLP analysis revealed three bands (670, 423 and 247 bp) in patient 2 and her father and two bands (423 and 247 bp) in her mother and 50 controls. It is concluded that LCAH should be considered in girls with early onset of adrenal insufficiency and that steroid profiles, karyotype analysis, adrenal ultrasound and StAR gene analysis may be helpful for the definite diagnosis of LCAH.

Exome sequencing for the diagnosis of 46,XY disorders of sex development

CONTEXT

Disorders of sex development (DSD) are clinical conditions where there is a discrepancy between the chromosomal sex and the phenotypic (gonadal or genital) sex of an individual. Such conditions can be stressful for patients and their families and have historically been difficult to diagnose, especially at the genetic level. In particular, for cases of 46,XY gonadal dysgenesis, once variants in SRY and NR5A1 have been ruled out, there are few other single gene tests available.

OBJECTIVE

We used exome sequencing followed by analysis with a list of all known human DSD-associated genes to investigate the underlying genetic etiology of 46,XY DSD patients who had not previously received a genetic diagnosis.

DESIGN

Samples were either submitted to the research laboratory or submitted as clinical samples to the UCLA Clinical Genomic Center. Sequencing data were filtered using a list of genes known to be involved in DSD.

RESULTS

We were able to identify a likely genetic diagnosis in more than a third of cases, including 22.5% with a pathogenic finding, an additional 12.5% with likely pathogenic findings, and 15% with variants of unknown clinical significance.

CONCLUSIONS

Early identification of the genetic cause of a DSD will in many cases streamline and direct the clinical management of the patient, with more focused endocrine and imaging studies and better-informed surgical decisions. Exome sequencing proved an efficient method toward such a goal in 46,XY DSD patients.

The role of anti-Mullerian and inhibin B hormones in the evaluation of 46,XY disorders of sex development

OBJECTIVE

To assess the sensitivity and specificity of anti-Mullerian hormone (AMH) and inhibin B for diagnosis of 46,XY disorders of sex development (DSD).

PATIENTS AND METHODS

The study included 43 patients of 46,XY DSD and compared them with 43 healthy, male, age matched controls. All patients underwent karyotyping, assessment of testosterone, dihydrotestosterone (DHT) and Δ4-androstendione (Δ4A) basal and after human chorionic gonadotropin (HCG) testing. Basal dehydroepiandrosterone (DHEA) was measured. Ultrasonograghy was also done and some cases underwent laparoscopy or gonadal biopsies. Basal AMH and inhibin B were measured in both cases and controls.

RESULTS

The mean age of patients was 5.16±4.24 years. There were significant correlations between basal AMH and HCG stimulated testosterone and DHT (r=0.64; p<0.001 and r=0.52; p<0.001, respectively). Also, significant positive correlations were found between inhibin B and HCG as well as stimulated testosterone and DHT (r=0.62; p<0.001 and r=0.44; p=0.003, respectively). A highly significant correlation was found between AMH and inhibin B (r=0.78; p<0.001). The sensitivity of AMH was (96.6%), specificity (60.7%), NPV (89.5%) and PPV (83.6%). Best cut-off value was (27.11 IU/mL) while overall accuracy was (85%). The sensitivity of inhibin B was (96.6%), specificity (67.9%), NPV (90.5%), PPV (86.2%), and best cut-off value was (41.9 IU/mL) with an overall accuracy (87%).

CONCLUSION

AMH and inhibin B are valuable, and reliable noninvasive parameters for the detection of functioning testicular tissues in prepubertal patients.

Insights into the coexistence of two mutations in the same LHCGR gene locus causing severe Leydig cell hypoplasia

BACKGROUND

Leydig cell hypoplasia is a rare autosomal recessive condition that interferes with the normal development of male external genitalia in 46,XY individuals. It is mediated by mutations in the lutropin/choriogonadotropin receptor gene, resulting in the impairment of either the binding of hormone or signal transduction.

OBJECTIVE/DESIGN

We report a 32-year-old female patient with severe Leydig cell hypoplasia due to a novel homozygote nonsense mutation in exon 10 (c.907C>T, p.Gln303Ter) of the lutropin/choriogonadotropin receptor gene. Interestingly, a second mutation was found (c.935A>G, p.Asn312Ser) downstream of the disruption of the gene sequence.

CONCLUSIONS

This case report demonstrates the coexistence of a novel homozygote nonsense mutation with a second mutation in the same hormone binding domain, expanding the genotypic spectrum of lutropin-choriogonadotropic hormone receptor gene mutations. The first diagnosis of this mutation in an adult 46,XY female patient from Morocco underlines the importance of thorough clinical and genetic examination, not only in pre- and post-pubertal children but also in adults originating from conservative socio-cultural backgrounds.