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

CONTEXT

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

OBJECTIVE

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

DESIGN/PATIENTS

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

RESULTS

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

CONCLUSIONS

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

Swyer Syndrome: A Case of Dysgerminoma Solely within the Fallopian Tube

BACKGROUND

46XY pure gonadal dysgenesis (Swyer syndrome) is a rare disorder of sexual development. Patients have a 46XY karyotype, though phenotypically they appear female with normal external genitalia and vagina. Although patients exhibit normal Müllerian structures (uterus, fallopian tubes, and vagina), they possess a pair of bilateral undifferentiated gonad streaks. Delayed puberty and primary amenorrhea are the common presentations. There is an increased risk of developing tumors in the gonads and therefore a bilateral gonadectomy is recommended.

CASE

A 16-year-old girl who presented with primary amenorrhea was diagnosed with Swyer syndrome. She underwent prophylactic bilateral gonadectomy and salpingectomies. She was discovered to have no gonadal malignancy, conversely dysgerminoma solely within the fallopian tube.

SUMMARY AND CONCLUSION

Both bilateral salpingectomies and bilateral gonadectomies should be recommended as the operation of choice in patients with Swyer Syndrome.

Expanding the spectrum of syndromic PPP2R3C-related XY gonadal dysgenesis to XX gonadal dysgenesis

Homozygous variants in PPP2R3C have been reported to cause a syndromic 46,XY complete gonadal dysgenesis phenotype with extragonadal manifestations (GDRM, MIM# 618419) in patients from four unrelated families, whereas heterozygous variants have been linked to reduced fertility with teratozoospermia (SPGF36, MIM# 618420) in male carriers. We present eight patients from four unrelated families of Turkish and Indian descent with three different germline homozygous PPP2R3C variants including a novel in-frame duplication (c.639_647dupTTTCTACTC, p.Ser216_Tyr218dup). All patients exhibit recognizable facial dysmorphisms allowing gestalt diagnosis. In two 46,XX patients with hypergonadotropic hypogonadism and nonvisualized gonads, primary amenorrhea along with absence of secondary sexual characteristics and/or unique facial gestalt led to the diagnosis. 46,XY affected individuals displayed a spectrum of external genital phenotypes from ambiguous genitalia to complete female. We expand the spectrum of syndromic PPP2R3C-related XY gonadal dysgenesis to both XY and XX gonadal dysgenesis. Our findings supported neither ocular nor muscular involvement as major criteria of the syndrome. We also did not encounter infertility problems in the carriers. Since both XX and XY individuals were affected, we hypothesize that PPP2R3C is essential in the early signaling cascades controlling sex determination in humans.

Mode of delivery of women with Swyer syndrome in a German case series

OBJECTIVES

For women with Swyer Syndrome, a 46,XY gonadal dysgenesis, full term pregnancies are possible after oocyte donation. According to literature, mode of delivery is almost always by Caesarean section for various reasons. Medical indications are multiple pregnancies and related complications, preeclampsia, an androgynous shaped pelvis and failed induction of labor. Elective Caesarean sections were performed based on maternal request and medical recommendation.

METHODS

Following careful examination and shared decision making, we planned a spontaneous delivery with a patient with Swyer syndrome and tested the different hypotheses regarding anatomical and functional features according to literature. In addition, deliveries of women with Swyer Syndrome were analyzed in a German multicenter case series.

RESULTS

A total of seven women with Swyer syndrome with a total of 10 pregnancies were identified, who later gave birth to twelve live-born children. Seven out of 10 births were performed by elective and non-elective Caesarean section, three births took place vaginally.

CONCLUSIONS

In summary, the risk of Caesarean section delivery has increased, but spontaneous delivery can be attempted in the event of inconspicuous findings.

A Unique Presentation of XY Gonadal Dysgenesis in Frasier Syndrome due to WT1 Mutation and a Literature Review

Frasier syndrome (FS), a rare disease caused by inherited or de novo mutation in Wilm's Tumor suppressor gene 1 (WT1), is characterized by slow progressive nephropathy, XY gonadal dysgenesis (XY-DSD), and increased risk for gonadal tumors. Early childhood (1-6 years) nephropathy progresses with age to refractory nephrotic syndrome, and end-stage renal failure in late adolescence, when delayed puberty and/or primary amenorrhea are clinically evident. We report a unique case of FS presenting initially with primary amenorrhea at 16 years, without previous or concomitant renal damage. Only subsequently she developed an extremely late-onset nephropathy. Genetic analysis revealed the IVS9 + 5 G>A mutation in intron 9 of the WT1 gene. This clinical presentation and review of WT1 literature highlights the importance of considering FS in the differential diagnosis of patients with 46,XY disorders of Sexual development, even without nephropathy. Furthermore, the identification WT1 gene mutation prior to evident renal dysfunction indicates an immediate and close surveillance of renal function enabling an optimal and timely medical response.

State of the art review in gonadal dysgenesis: challenges in diagnosis and management

Gonadal dysgenesis, a condition in which gonadal development is interrupted leading to gonadal dysfunction, is a unique subset of disorders of sexual development (DSD) that encompasses a wide spectrum of phenotypes ranging from normally virilized males to slightly undervirilized males, ambiguous phenotype, and normal phenotypic females. It presents specific challenges in diagnostic work-up and management. In XY gonadal dysgenesis, the presence of a Y chromosome or Y-chromosome material renders the patient at increased risk for developing gonadal malignancy. No universally accepted guidelines exist for identifying the risk of developing a malignancy or for determining either the timing or necessity of performing a gonadectomy in patients with XY gonadal dysgenesis. Our goal was to evaluate the literature and develop evidence-based medicine guidelines with respect to the diagnostic work-up and management of patients with XY gonadal dysgenesis. We reviewed the published literature and used the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) system when appropriate to grade the evidence and to provide recommendations for the diagnostic work-up, malignancy risk stratification, timing or necessity of gonadectomy, role of gonadal biopsy, and ethical considerations for performing a gonadectomy. Individualized health care is needed for patients with XY gonadal dysgenesis, and the decisions regarding gonadectomy should be tailored to each patient based on the underlying diagnosis and risk of malignancy. Our recommendations, based on the evidence available, add an important component to the diagnostic and management armament of physicians who treat patients with these conditions.

Seedless orchids: Issues in the anorchid adult

Disorders of sexual differentiation (DSD) are among the challenging problems in the field of endocrinology. When presenting late in an adult the therapeutic as well as diagnostic issues may be different and difficult. Bilateral anorchia is rare. The desire of future parenting is a real challenge when such patients ask for their own biological generations. This case depicts the late presentation of DSD in an anorchid adult and the management issues.