Cell-free fetal DNA sex determination identified a maternal SRY gene with a known X chromosome deletion


  • Funding sources: None

  • Conflicts of interest: None declared


What's already known about this topic?

  • Cell-free fetal DNA testing is commonly used as a noninvasive method of determing fetal sex.
  • Presence of sex-determining region Y (SRY) on the X chromosome is associated with a variable sexual phenotype.

What does this study add?

  • Details an unexpected cell-free fetal DNA sexing result.
  • Highlights the importance of using the technique of quantitative polymerase chain reaction in free fetal DNA testing.
  • If a similar result is found again, we would recommend further testing of the maternal chromosomes to look for a translocation encompassing the sex-determining region Y (SYR) gene.