From genetic diagnosis to healthy live births: implementing an integrated PGT-M pathway for 21-hydroxylase deficiency

This study aimed to assess the clinical efficacy of a comprehensive reproductive management pathway integrating genetic diagnosis, preimplantation genetic testing for monogenic disorders and aneuploid (PGT-M & PGT-A) and prenatal diagnosis for families affected by CYP21A2 variant related 21-hydroxylase deficiency (21-OHD).

We performed a retrospective analysis of three families affected by 21-OHD. Definitive genetic diagnosis of the CYP21A2 locus was established using Multiplex Ligation-dependent Probe Amplification (MLPA) and Sanger sequencing. In parallel, whole-exome sequencing (WES) was performed to rule out other causes of congenital adrenal hyperplasia(CAH). The Asian Screening Array (ASA) was employed for PGT-M linkage analysis, while next-generation sequencing (NGS) was used for PGT-A. Prenatal diagnosis was performed to validate the PGT-M and PGT-A results.

Pathogenic CYP21A2 variants were confirmed in all families. PGT-M enabled all couples to obtain transferable embryos, which were either genetically normal or carriers. Embryo transfer resulted in two clinical pregnancies and one miscarriage. Prenatal diagnosis in the two ongoing pregnancies showed complete concordance with the PGT-M profiles. Both pregnancies resulted in the delivery of healthy offspring.

An integrated pathway combining genetic diagnosis, PGT-M, and prenatal diagnosis is a feasible and effective strategy for families with CYP21A2 variant related 21-OHD. This real-world application suggests the potential clinical utility of this multidisciplinary approach. Nevertheless, the conclusions should be interpreted with caution due to the small cohort size, and further studies with larger samples are required to confirm the efficacy and reproducibility of this integrated strategy.