Establishing a molecular genetic diagnosis in children with Differences of Sex Development - a clinical approach

Clinical utility of early rapid genome sequencing in the evaluation of patients with differences of sex development

Establishing an early and accurate genetic diagnosis among patients with differences of sex development (DSD) is crucial in guiding the complex medical and psychosocial care they require. Genetic testing routinely utilized in clinical practice for this population is predicated upon physical exam findings and biochemical and endocrine profiling. This approach, however, is inefficient and unstandardized. Many patients with DSD, particularly those with 46,XY DSD, never receive a molecular genetic diagnosis. Rapid genome sequencing (rGS) is gaining momentum as a first-tier diagnostic instrument in the evaluation of patients with DSD given its ability to provide greater diagnostic yield and timely results. We present the case of a patient with nonbinary genitalia and systemic findings for whom rGS identified a novel variant of the WT1 gene and resulted in a molecular diagnosis within two weeks of life. This timeframe of diagnosis for syndromic DSD is largely unprecedented at our institution. Rapid GS expedited mobilization of a multidisciplinary medical team; enabled early understanding of clinical trajectory; informed planning of medical and surgical interventions; and guided individualized psychosocial support provided to the family. This case highlights the potential of early rGS in transforming the evaluation and care of patients with DSD.

Individuals with numerical and structural variations of sex chromosomes: interdisciplinary management with focus on fertility potential

Diagnosis and management of individuals who have differences of sex development (DSD) due to numerical or structural variations of sex chromosomes (NSVSC) remains challenging. Girls who have Turner syndrome (45X) may present with varying phenotypic features, from classical/severe to minor, and some remain undiagnosed. Boys and girls who have 45,X/46,XY chromosomal mosaicism may have Turner syndrome-like features and short stature; therefore, unexplained short stature during childhood requires karyotype analysis in both sexes, particularly if characteristic features or atypical genitalia are present. Many individuals with Klinefelter syndrome (47XXY) remain undiagnosed or are only diagnosed as adults due to fertility problems. Newborn screening by heel prick tests could potentially identify sex chromosome variations but would have ethical and financial implications, and in-depth cost-benefit analyses are needed before nationwide screening can be introduced. Most individuals who have NSVSC have lifelong co-morbidities and healthcare should be holistic, personalized and centralized, with a focus on information, psychosocial support and shared decision-making. Fertility potential should be assessed individually and discussed at an appropriate age. Oocyte or ovarian tissue cryopreservation is possible in some women who have Turner syndrome and live births have been reported following assisted reproductive technology (ART). Testicular sperm cell extraction (TESE) is possible in some men who have 45,X/46,XY mosaicism, but there is no established protocol and no reported fathering of children. Some men with Klinefelter syndrome can now father a child following TESE and ART, with multiple reports of healthy live births. Children who have NSVSC, their parents and DSD team members need to address possibilities and ethical questions relating to potential fertility preservation, with guidelines and international studies still needed.

Babies born with ambiguous genitalia: Developing an educational resource for Australian midwives

PROBLEM AND BACKGROUND

The birth of a baby with ambiguous genitalia is rare and usually unexpected. Parents often receive inconsistent language from health-professionals after the birth. Initial interaction with the birth team has long-term consequences for families with babies born with ambiguous genitalia.

AIM

Understand the current practices on the day of birth and explore knowledge gaps for midwives regarding babies born with ambiguous genitalia. Develop educational content that can enable midwives to respond appropriately when the sex of a baby is unclear.

METHODS

This study included two phases, utilising qualitative descriptive research design with semi-structured interviews to understand the experiences of midwives caring for babies with ambiguous genitalia and their families. The findings informed the development a midwifery educational resource using these qualitative findings.

FINDINGS

Our analysis of 14 interviews with Australian midwives identified that they had no formal education to support families with a baby with ambiguous genitalia. Emotional support, advocacy and medical information translation were areas midwives perceived as essential skills to support these families.

DISCUSSION

Midwives provide a unique role in parental birth experiences. Themes that arose emphasised their psychosocial support role but lacked formal education and guidance on this topic. Midwives had learnt from the media about babies born with ambiguous genitalia and wanted evidence-based education to support parents. Midwife education focusing on both psychosocial and clinical care for parents and their baby with ambiguous genitalia is crucial.

CONCLUSION

Midwives can play a pivotal role in supporting parents with a baby with ambiguous genitalia. Themes from this qualitative study informed the development of a midwifery education digital resource.