Introduction to 46,XY Differences in Sex Development

Establishing an accurate 46,XY DSD molecular diagnosis is essential for the clinical management of children with differences in sex development. These conditions represent a complex group of disorders where chromosomal sex does not align with phenotypic appearance. Furthermore, recent advancements in genomic technology have significantly improved our ability to identify the underlying genetic causes. A large-scale study conducted at a tertiary hospital in India has now provided critical insights into the molecular landscape of these conditions within the Indian population.

The Role of Targeted Genetic Testing

Researchers evaluated 147 children with 46,XY DSD to determine the efficacy of a stepwise genetic approach. Initially, clinicians performed targeted Sanger sequencing for common defects, specifically looking at the SRD5A2 and AR genes. This approach targeted patients with suspected 5α-reductase type 2 deficiency or androgen insensitivity syndrome. Consequently, this initial phase successfully identified pathogenic variants in 44 subjects. Moreover, the study utilized a 155-gene panel for next-generation sequencing in cases where initial tests were negative. This systematic methodology ensures that doctors can optimize resources while maintaining high diagnostic accuracy.

Advancing 46,XY DSD Molecular Diagnosis Through NGS

The application of next-generation sequencing (NGS) revealed pathogenic variants in an additional 20 subjects across 12 different genes. Notably, NR5A1 emerged as the most frequent variant among those tested via NGS. Therefore, the overall diagnostic yield for the cohort reached 46%. This finding highlights the importance of incorporating modern sequencing technologies into the diagnostic algorithm. Additionally, the study found that SRD5A2, AR, and NR5A1 remain the most common genetic factors in the Indian context. However, clinicians must still carefully correlate these genetic findings with biochemical and radiological data to ensure correct interpretation.

Clinical Implications for Pediatric Management

Molecular findings directly influence long-term care decisions regarding reproduction, tumor risk management, and extragenital issues. Because many DSD conditions carry risks for germ cell tumors, early genetic identification allows for better surveillance. Furthermore, understanding the specific gene variant helps in counseling families about the prognosis and potential for gender identity development. Doctors should consider this stepwise testing model to improve the rate of successful 46,XY DSD molecular diagnosis in their clinical practice.

Frequently Asked Questions

Which genes are most commonly implicated in 46,XY DSD in India?

According to the study, SRD5A2, AR, and NR5A1 are the most frequently involved genes in the Indian cohort, accounting for the majority of molecular diagnoses.

What is the diagnostic yield of combining Sanger sequencing and NGS?

The combination of these methods provided a molecular diagnosis in approximately 46% of the patients, demonstrating a robust diagnostic success rate for such heterogeneous conditions.

How does genetic testing impact clinical management?

Molecular diagnosis guides clinicians in managing hormone replacement therapy, assessing future fertility, and determining the appropriate monitoring for potential tumor formation.

Disclaimer: This content is for informational and educational purposes only. It does not constitute medical advice or establish a doctor-patient relationship. Refer to the latest local and national guidelines for clinical practice.

References

Jain V et al. Clinical Characterization and Molecular Profiling by Targeted Next-Generation Sequencing in a Large Indian Cohort With 46,XY Differences in Sex Development. Clin Endocrinol (Oxf). 2026 Mar 08. doi: 10.1111/cen.70122. PMID: 41796107.

Bashamboo A, McElreavey K. Mechanism of Sex Determination and 46,XY Condition of Differences in Sex Development. Endocr Dev. 2014;27:186-197.

Ahmed SF, et al. Society for Endocrinology UK guidance on the initial evaluation of an infant or child with a suspected difference in sex development. Clin Endocrinol (Oxf). 2011;74(1):12-26.