Disorders of Sexual Development in Adult Women

The Use of Fluorescence In situ Hybridisation in the Diagnosis of Hidden Mosaicism in Egyptian Patients with Turner Syndrome

Background

Turner syndrome (TS) is the most common chromosomal abnormality in females. The diagnosis of TS is based on karyotyping of 30 blood lymphocytes. This technique does not rule out tissue mosaicism or low-grade mosaicism in the blood. Because of the associated risk of gonadoblastoma, mosaicism is especially important in case this involves a Y chromosome.

Aims

This study was set to determine the value of additional genetic studies such as fluorescent in situ hybridisation and the inclusion of buccal cells in search for mosaicism in TS patients.

Settings and Design

This cross-sectional, descriptive study was performed in Human Genetics Department, Medical Research Institute, Alexandria University.

Materials and Methods

Fluorescence in situ hybridisation technique was applied to lymphocyte cultures as well as buccal smears using centromeric probes for X and Y chromosomes. Genotype phenotype correlation was also evaluated.

Statistical Analysis Used

Descriptive study where categorical variables were described using number and percentage and continuous variables were described using mean and standard deviation.

Results

Fluorescence in situ hybridisation technique study detected hidden mosaicism in 60% of studied patients; 20% of patients had a cell line containing Y material, while 40% had variable degrees of X, XX mosaicism, and in the remaining 40% no second cell line was detected. Fluorescence in situ hybridisation study helped identify the origin of the marker to be Y in all patients. The introduction of an additional cell line helped in identifying mosaicism in patients with monosomy X. Virilisation signs were only observed among TS patients with Y cell line mosaicism. The clinical manifestations were more severe in patients with monosomy X than other mosaic cases.

Conclusions

Molecular cytogenetic investigation for all suspected cases of TS should be considered for appropriate treatment plan and genetic counselling.

Molecular genetics and general management of androgen insensitivity syndrome

Androgen insensitivity syndrome (AIS) is a rare genetic disorder that affects the development of the male reproductive system in individuals with a 46,XY karyotype. In addition to physical impacts, patients with AIS may face psychological distress and social challenges related to gender identity and acceptance. The major molecular etiology of AIS results from hormone resistance caused by mutations in the X-linked androgen receptor (AR) gene. Depending on the severity of androgen resistance, the wide spectrum of AIS can be divided into complete AIS (CAIS), partial AIS (PAIS), or mild AIS (MAIS). Open issues in the treatment and management of AIS include decisions about reconstructive surgery, genetic counseling, gender assignment, timing of gonadectomy, fertility and physiological outcomes. Although new genomic approaches have improved understanding of the molecular causes of AIS, identification of individuals with AIS can be challenging, and molecular genetic diagnosis is often not achievable. The relationship between AIS genotype and phenotype is not well established. Therefore, the optimal management remains uncertain. The objective of this review is to outline the recent progress and promote understanding of AIS related to the clinical manifestation, molecular genetics and expert multidisciplinary approach, with an emphasis on genetic etiology.

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.

Methods

The two 46,XY DSD cases were identified and sequenced. In order to identify the source of the compound heterozygous p.Q6X/p.H232R mutation, the parents, maternal grandparents, and maternal uncle were sequenced. Since p.Q6X mutation is a nonsense mutation, p.H232R mutation was transfected into HEK293 cells and dihydrotestosterone (DHT) production were analyzed by liquid chromatography–mass spectrometry (LC–MS) for 5α-reductase 2 enzyme activities test. Apparent michaelis constant (Km) were measured of p.H232R mutation to analyze the binding ability change of 5α-reductase 2 enzyme with testosterone (T) or NADPH.

Results

The sequence results showed that the two 46,XY DSD cases were the compound heterozygous p.Q6X/p.H232R mutation, of which the heterozygous p.Q6X mutation originating from maternal family and heterozygous p.H232R mutation originating from the paternal family. The function analysis confirmed that p.H232R variant decreased the DHT production by LC–MS test. The Km analysis demonstrated that p.H232R mutation affected the binding of SRD5A2 with T or NADPH.

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.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13052-022-01243-4.

Neoplasia in Turner syndrome: a retrospective cohort study in a tertiary referral centre in Belgium

OBJECTIVES

Patients with Turner syndrome (TS), the most common sex chromosome abnormality in women, can suffer from a variety of well-researched reproductive, cardiovascular, metabolic, and autoimmune comorbidities. Few studies investigate the neoplasia risk. We assessed the general neoplasia risk in TS women, and more specifically, the gonadoblastoma/dysgerminoma risk in the subgroup with Y chromosome mosaicism, and evaluated potential risk factors for neoplasia development, such as karyotype, metabolic and autoimmune comorbidity, and treatment with growth hormone and/or estrogen replacement.

DESIGN

10-year retrospective cohort study in a tertiary referral centre in Belgium.

RESULTS

105 TS women were included (median age 29; range 2-69). Six malignant tumours were detected in 5 (4.8%) patients (SIR = 0.6, 95% CI 0.2-1.0). In addition, 2 benign meningiomas were observed, resulting in 3 (2.9%) tumours of the central nervous system (CNS; SIR = 19.9, 95% CI 4.0-35.8). No breast cancer was noted. Benign neoplasms occurred in 22 women (21.0%), with skin lesions being the most frequent. All patients with Y chromosome mosaicism (n = 9; 8.6%) underwent prophylactic gonadectomy, but gonadoblastoma/dysgerminoma was not detected. A weak association was found between any tumour type and autoimmune comorbidity (r = 0.24; p = 0.02).

CONCLUSION

The overall malignancy risk was not increased, but a different pattern of occurrence is apparent, with an increased risk of CNS and skin tumours and a decreased breast cancer risk. Gonadoblastoma/dysgerminoma was not reported. There is a need for centralised multidisciplinary care and prospective research to unravel and predict the neoplasia risk.

Healthcare transition for patients with differences of sexual development and complex urogenital conditions

Children with major congenital anomalies are able to obtain a high level of care in pediatric care settings. In contrast, adult care models emphasize patient responsibility in ensuring their health care needs are met. As patients make this transition, they may fall through the medical "safety net" and struggle to find quality care because of their lack of preparation. Transitional care, including tailored and purposeful medical and social support services, can serve as a bridge across systems and facilitate the safe and effective transfer of young adults with special health care needs from pediatric to adult care. Transitional care prepares youth to manage their own care, effectively use health services, and navigate the shift from distinctly different pediatric to adult models of health care. For unique patient populations such as those with disorders of sexual development and congenital genitourinary conditions, this preparation is vitally important to maximize lifelong functioning and well-being.

Long-term consequences of androgen insensitivity syndrome

Androgen insensitivity syndrome (AIS) is one of the most common sexual developmental disorders. According to the grade of the remaining androgen receptor (AR) function, AIS is classified as complete (CAIS), partial (PAIS) or mild (MAIS). In CAIS, the prevalence of germ cell tumours is increased compared with the general population. Although patients with CAIS used to undergo gonadectomy before puberty, nowadays a gonadectomy is recommended after spontaneous puberty, and up to 15% of patients retain their gonads. Nevertheless, the risk of germ cell tumour increases gradually after puberty. Annual follow-up with ultrasound or magnetic resonance imaging (MRI) is recommended. Unfortunately, these imaging methods are not sensitive enough for the diagnosis of an in situ germ cell tumour. In PAIS, the risk of germ cell tumour is higher than in CAIS; therefore, an early gonadectomy or an orchidopexy is indicated. Optimal hormone replacement therapy (HRT) is necessary for long-term health. The risks of osteopenia and of regimen osteoporosis are higher, ESPECIALLY in patients with early gonadectomy. Infertility is the rule in CAIS and PAIS. A few mutations do not affect fertility detrimentally, and these are responsible for MAIS. In PAIS leading to a predominantly male phenotype or ambiguous genitalia, multiple surgical procedures for gynaecomastia and/or hypospadias are required. Some small studies have found a higher risk of obesity, hyperlipidaemia and impaired insulin sensitivity. Psychological support is essential, as the prevalence of psychiatric disorders is increased. In conclusion, the diagnosis of AIS has long-term consequences for which shared decision-making (physicians, patients, parents) is appropriate.

Challenges and Opportunities in Adolescent Gynecology Patients with Surgically-Treated Congenital and Acquired Anomalies: Transition of Care from Pediatric to Adult Surgery

The transition from adolescence to young adulthood in patients with reproductive health care needs such as disorders of sexual development and congenital anomalies is a complex process that occurs over several years. The transition process for these patients is still poorly understood. The patients with disorders of sexual development and reproductive issues have specific and unique issues regarding timing of disclosure of diagnosis, genital examinations, gonadectomy, vaginal treatments, surgical procedures, hormone replacement therapy, use of long-term medication, and potential cancer screening. The purpose of this review is to briefly describe complex genital malformations and their associated anomalies with long-term concerns and then provide an overview of what has been published at this time regarding the transition of care to provide some guidance for providers who care for those patients.

Isochromosome Mosaic Turner Syndrome: A Case Report

Turner syndrome (TS) with an isochromosome mosaic karyotype 45,X/46,X,i(X) (q10) is an unusual variant, with only an 8-9% prevalence among women with TS based on international studies and 15% of all TS in the Philippines. Clinical features are atypical and any case should be investigated to detect potential complications.

A 20-year-old female came in due to amenorrhea and alopecia. Physical examination revealed short stature, cubitus valgus and Tanner Stage 1 pubic hair and breast development. Transrectal ultrasound revealed absent ovaries and infantile uterus. Hormonal evaluation revealed hypergonadotropic hypogonadism. Bone aging was that of a 13-yearold for females with non-fusion of epiphyseal plates. Cytogenetic study revealed 45,X [37]/46, X, i (X) (q10)[13]. This is consistent with a variant Isochromosome Mosaic Turner Syndrome (IMTS).

She was screened for medical complications. Audiogram and two-dimensional echocardiography were unremarkable. She has dyslipidemia and was given a statin. She has subclinical hypothyroidism with positive test for anti-thyroglobulin antibody. Her intelligence quotient (IQ) was below average. She received conjugated estrogen and progesterone that patterned the hormonal changes in a normal menstrual cycle. On the third week of hormonal therapy, she developed breast mound and on the fourth week, she had her first menstrual period. Her alopecia spontaneously resolved.

The case is a variant of Turner Syndrome requiring supportive, medical and psychological care.

46,XY Disorder of Sex Development Caused by 17α-Hydroxylase/17,20-Lyase Deficiency due to Homozygous Mutation of CYP17A1 Gene: Consequences of Late Diagnosis

Context

Congenital adrenal hyperplasia (CAH) is an autosomal recessive disease due to specific enzyme deficiencies in the adrenal steroidogenesis pathway.

Case Description

A 40-year-old Chinese woman was referred to the Endocrine Unit for the work-up of a syndrome characterized by long-lasting and multidrug resistant high blood pressure, severe hypokalemia with metabolic alkalosis, and primary amenorrhea. The patient presented with sexual infantilism, lack of breast development, absence of axillary and pubic hair, tall stature, and slenderness. CT scan revealed enlarged adrenal glands bilaterally and the absence of the uterus, the ovaries, and the Fallopian tubes. Furthermore, diffuse osteopenia and osteoporosis and incomplete ossification of the growth plate cartilages were demonstrated. Chromosomal analysis showed a normal male 46,XY, karyotype, and on molecular analysis of the CYP17A1 gene she resulted homozygous for the g.4869T>A; g.4871delC (p.Y329Kfs?) mutation in exon 6. Hydrocortisone and ethinyl-estradiol supplementation therapy led to incomplete withdrawal of antihypertensive drug and breast development progression to Tanner stage B2 and slight height increase, respectively.

Conclusions

We describe a late-discovered case of CAH with 46,XY disorder of sex development. Deficiency of 17α-hydroxylase/17,20-lyase due to a homozygous CYP17A1 gene mutation was the underlying cause. Laboratory, imaging, and genetic features are herein reported and discussed.