Mutation Analysis of the SRY Gene in a Patient with Turner Syndrome

Testis-determining factor (TDF) is an alternative term for the sex-determining region (SRY) gene found on the Y chromosome. SRY gene mutations can cause a wide range of sex development issues. The single-exon SRY gene is a short and intronless sex-determining gene with a DNA-binding high mobility group (HMG) box that is highly conserved. We performed cytogenetic analysis on one patient with Turner syndrome having a 45,X/46,XY chromosomal composition. Further, we used polymerase chain reaction, single-stranded conformational polymorphism, and automated DNA sequencing to detect a substitution of C?A (missense mutation) at codon 139, which led to an amino acid shift from Proline to Glutamine (P139Q) outside but downstream of the HMG box in the SRY gene. No further alterations in the SRY gene were discovered in the patient. The absence of one X chromosome in 88% of the patient's cells might have resulted in a wide variety of phenotypic complications.