Mutational Analysis of Compound Heterozygous Mutation P.q6x/p.h232r in Srd5a2 Causing 46,xy Disorder of Sex Development

Background: Over 100 mutations in the SRD5A2 gene have been identified in subjects with 46,XY disorder of sex development (DSD). Exploration of SRD5A2 mutations and elucidation of the molecular mechanisms behind their effects should reveal the functions of the domains of the 5α-reductase 2 enzyme and identify the cause of 46,XY DSD. Previously, we reported a novel compound heterozygous p.Q6X/p.H232R mutation of the SRD5A2 gene in a case with 46,XY DSD. Whether the compound heterozygous p.Q6X/p.H232R mutation in this gene causes 46,XY DSD requires further exploration. Results: To clarify the cause of 46,XY DSD in the affected family focused on here, SRD5A2 sequencing was performed. Heterozygous p.H232R mutation was identified in the proband’s father, so we concluded that this mutation originated from the paternal side of the family and did not cause 46,XY DSD. Meanwhile, heterozygous p.Q6X mutation was identified in the proband’s mother, maternal uncle, and maternal grandfather, indicating that this mutation originated from maternal side of the family and did not cause 46,XY DSD. To clarify the effect of the p.H232R mutation in SRD5A2 on dihydrotestosterone (DHT) production, p.H232R mutant SRD5A2 plasmids were transfected into HEK293 cells. LC-MS indicated that DHT production decreased compared with that in cells transfected with wild-type SRD5A2.Conclusions: Our findings confirmed that the compound heterozygous p.Q6X/p.H232R mutation in the SRD5A2 gene is the cause of 46,XY DSD. p.H232R mutation reduced DHT production while attenuating the catalytic efficiency of the 5α-reductase 2 enzyme.

Recent advancement in the treatment of boys and adolescents with hypogonadism

Clinical manifestations and the need for treatment varies according to age in males with hypogonadism. Early foetal-onset hypogonadism results in disorders of sex development (DSD) presenting with undervirilised genitalia whereas hypogonadism established later in foetal life presents with micropenis, cryptorchidism and/or micro-orchidism. After the period of neonatal activation of the gonadal axis has waned, the diagnosis of hypogonadism is challenging because androgen deficiency is not apparent until the age of puberty. Then, the differential diagnosis between constitutional delay of puberty and central hypogonadism may be difficult. During infancy and childhood, treatment is usually sought because of micropenis and/or cryptorchidism, whereas lack of pubertal development and relative short stature are the main complaints in teenagers. Testosterone therapy has been the standard, although off-label, in the vast majority of cases. However, more recently alternative therapies have been tested: aromatase inhibitors to induce the hypothalamic-pituitary-testicular axis in boys with constitutional delay of puberty and replacement with GnRH or gonadotrophins in those with central hypogonadism. Furthermore, follicle-stimulating hormone (FSH) priming prior to hCG or luteinizing hormone (LH) treatment seems effective to induce an enhanced testicular enlargement. Although the rationale for gonadotrophin or GnRH treatment is based on mimicking normal physiology, long-term results are still needed to assess their impact on adult fertility.

CYTOGENETIC ANALYSIS OF PATIENTS WITH AMBIGUOUS GENITALIA

Objective: To determine the magnitude and classification of cases of ambiguous genitalia presenting to our setup. Study Design: Cross-sectional study. Place and Duration of Study: Department of Haematology, Armed Forces Institute of Pathology, Rawalpindi Pakistan, from Aug 2018 to Feb 2019. Methodology: All the patients with ambiguous genitalia referred for cytogenetic analysis, were included in the study. The patients were subjected to a detailed history and physical examination. The record of radiological investigations was were obtained. Cytogenetic analysis was performed using the conventional G-banding technique. Hormonal testing included 17- hydroxyprogesterone (17-OHP) levels was also performed. Results: Fifty-one cases of ambiguous genitalia were studied. The median age was 15 months. Thirty-three patients (64.7%) had a 46XY karyotype, 17 (33.3%) had a 46XX karyotype while 1 (1.9%) had 45X/46, XY mosaic karyotype. Thirty patients (58.8%) were products of consanguineous marriage. Congenital adrenal hyperplasia was diagnosed in 12 cases (70.5%) of 46 XX karyotype and in 3 cases (9%) of 46XY karyotype. Conclusion: Ambiguous genitalia, currently categorized as disorders of sex development, are not uncommon in our populartion. Increased awareness and early diagnosis are crucial to prevent life threatening complications of congenital adrenal hyperplasia, to determine sex of rearing, and to counsel the parents or patients.

Stem cells and organs-on-chips: new promising technologies for human infertility treatment

Having biological children remains an unattainable dream for most couples with reproductive failure or gonadal dysgenesis. The combination of stem cells with gene editing technology and organ-on-a-chip models provides unique opportunity for infertile patients with impaired gametogenesis caused by congenital disorders in sex development or cancer survivors. But, how will these technologies overcome human infertility? This review discusses the regenerative mechanisms, applications and advantages of different types of stem cells for restoring gametogenesis in infertile patients, as well as major challenges that must be overcome prior to clinical application. The importance and limitations of in vitro generation of gametes from patient-specific human induced pluripotent stem cells (hiPSCs) will be discussed in the context of human reproduction. The potential role of organ-on-a-chip models that can direct differentiation of hiPSCs-derived primordial germ cell-like cells to gametes and other reproductive organoids is also explored. These rapidly evolving technologies provide future prospects for improving fertility to individuals and couples who experience reproductive failure.

Disorder of Sex Development, Mosaic Genetic Disorder 45x, 46xy: A Case Report

Background. Disorder of sex development (DSD) is a congenital disorder associated with interference in chromosomes, gonads, or sexes anatomically. Individual affected with DSD can be recognized since birth due to external genital ambiguity. Sexual chromosome DSD occurred because sexual chromosome numeric or structural disorder. Mosaic karyotype 45X/46XY is among the rare sexual chromosome DSD with incidence less than 1:15,000 live births. DSD individuals are susceptible to stigmatization. This can cause stress, negative emotion, and social isolation. Therefore, DSD individual management should be done as optimal as possible. Case Presentation: Twelve years old girl complaining a bump arose from anterior side of her genital resembles male genital since 4 years prior to admission without micturition and defecation complains. Patient has not experienced menarche. On external genital examination, we found the normal female external genital such as mons pubis, pubic hair, labia majora, labia minora, hymen, perineum, but without clitoris which in this case it is replaced by a glans of penis, arising from anterior commissure of labia majora area, with an urethral estuary. Before the management is done, patient underwent multidiscipline consultations and further examinations. Subsequently, it was approved that the joint conference formation consisting obstetric and gynecology, urologist, and pediatric endocrinologist to determine the optimal management for the patient. Conclusion: In this case, diagnosis was made with history taking, clinical examination, and supporting investigation such as ultrasound imaging and could be followed by biochemistry test, voiding cystourethrography or genitogram to determine next management. Counseling should be done in detail towards the family to know what action is best for the patient. Multidiscipline team was required to get the optimum result either in medical, ethical, or religious point of view. Surgery in this case was considered followed by long term therapy afterwards.

Disorders of Sex Development of Adrenal Origin

Disorders of Sex Development (DSD) are anomalies occurring in the process of fetal sexual differentiation that result in a discordance between the chromosomal sex and the sex of the gonads and/or the internal and/or external genitalia. Congenital disorders affecting adrenal function may be associated with DSD in both 46,XX and 46,XY individuals, but the pathogenic mechanisms differ. While in 46,XX cases, the adrenal steroidogenic disorder is responsible for the genital anomalies, in 46,XY patients DSD results from the associated testicular dysfunction. Primary adrenal insufficiency, characterized by a reduction in cortisol secretion and overproduction of ACTH, is the rule. In addition, patients may exhibit aldosterone deficiency leading to salt-wasting crises that may be life-threatening. The trophic effect of ACTH provokes congenital adrenal hyperplasia (CAH). Adrenal steroidogenic defects leading to 46,XX DSD are 21-hydroxylase deficiency, by far the most prevalent, and 11β-hydroxylase deficiency. Lipoid Congenital Adrenal Hyperplasia due to StAR defects, and cytochrome P450scc and P450c17 deficiencies cause DSD in 46,XY newborns. Mutations in SF1 may also result in combined adrenal and testicular failure leading to DSD in 46,XY individuals. Finally, impaired activities of 3βHSD2 or POR may lead to DSD in both 46,XX and 46,XY individuals. The pathophysiology, clinical presentation and management of the above-mentioned disorders are critically reviewed, with a special focus on the latest biomarkers and therapeutic development.