Clinical applicability of rapid detection of SRY and DYS14 genes in patients with disorders of sex development using an indigenously developed 5′ exonuclease based assay

摘要

Background: Life threatening conditions are associated with atypical genitalia in newborns. Analysis of genetic sex provides a clue to the underlying etiology in newborns with disorders of sex development (DSD) and can guide further endocrine investigations. Rapid diagnosis of genetic sex would be immensely useful in this situation. Traditionally used methods such as karyotype and fluorescence in situ hybridisation are time-consuming. Objectives: To study the clinical applicability of an indigenously developed rapid real-time polymerase chain reaction (RT-PCR) assay for the sex determining region on the Y chromosome (SRY gene) and the DYS14 locus in newborns with DSD. Methods: Clinical examination, endocrinological tests, RT-PCR analysis of SRY and DYS14 and karyotype was performed in 15 newborns with DSD. Results: Results of PCR were available within 4 h. Based on this report, in SRY/DYS14 positive cases, further tests for assessment of testicular function were done. In SRY negative cases, tests for congenital adrenal hyperplasia were done. On comparing PCR results with other tests, the Y chromosome was present on karyotype and testicular tissue was detected by endocrinological and/or histological methods in all (8/15) SRY positive cases. The SRY and DYS14 negative cases (7/15) did not have Y chromosome in the karyotype. Congenital adrenal hyperplasia (CAH) was the most common diagnosis in this group. Conclusions: The indigenously developed PCR for dual Y chromosome markers is rapid and sensitive. Further endocrine evaluation of newborns with DSD can be based on these results. Information of genetic sex partly allays the psychosocial distress associated with the condition.