Haplotyping-based preimplantation genetic testing for inherited cardiovascular disease: a multidisciplinary approach

Given the high morbidity, mortality, and hereditary risk of cardiovascular diseases (CVDs), their prevention and control have garnered widespread attention and remain central to clinical research. This study aims to assess the feasibility and necessity of haplotyping-based preimplantation genetic testing for the prevention of inherited CVD. A total of 15 preimplantation genetic testing for monogenic defect (PGT-M) cycles were performed in 12 CVD families from January 2016 to July 2022. All couples were affected by CVDs and carried specific causative genes (including MYH7, MYBPC3, TTN, TPM1, LMNA, KCNQ1, FBN1 and LDLR). Among the 10 couples with adequate genetic pedigree information, we utilized the karyomapping assay to obtain single-nucleotide polymorphisms (SNPs) allele data. For the 2 couples who had no reference in their family, we used single sperm next-generation sequencing (NGS) to realize haplotype construction. Linkage analysis was performed to deduce embryonic genotype, and aneuploidy was screened simultaneously. Prenatal diagnostic testing via amniocentesis at 18-22 weeks of gestation was performed to verify the genetic conditions of transferred embryos. In total, 120 embryos were examined in this study, and the results showed that only 26.7% (32/120) were mutation-free and euploid-confirmed embryos. Additionally, for female CVD patients, we convened a multidisciplinary team (MDT) to advise the couple on their fertility concerns and management measures during pregnancy and delivery. With our cooperation, 10 couples successfully obtained healthy babies not carrying the pathogenic mutations. The results of prenatal diagnostics were consistent with the results of PGT-M. Our study demonstrates that PGT-M based on haplotype analysis is reliable and necessary for the prevention of inherited CVDs. It also highlights the important value of multidisciplinary collaboration for CVD prevention and treatment. Inherited cardiovascular diseases (CVDs) present as a huge challenge for modern medical and health systems. Hundreds of genetic variants have been reported to cause CVD and the number of people with the disease is enormous and still on the rise globally. Here we recruited twelve couples suffering from inherited CVD and provided them with effective pre-implantation genetic testing for monogenic defect (PGT-M) strategy to avoid the occurrence of genetic defects in the offspring. Specifically, after embryo biopsy, we utilized karyomapping assay (for 10 couples with a family history) or next-generation sequencing (NGS) (for 2 couples having no reference in their pedigree) to obtain single-nucleotide polymorphisms (SNPs) allele data and then performed linkage analysis to deduce embryonic genotype. A total of 120 embryos from 15 PGT-M cycles were examined and 12 variants in 8 genes linked to inherited CVD were identified. Thirty-two mutation-free and euploid confirmed embryos were considered suitable for embryo transfer. Besides, for female CVD patients, we called up a multidisciplinary team (MDT) advising the couple on their fertility concerns and management measures of pregnancy and delivery. With our cooperation, 10 couples successfully obtain healthy babies not carrying the pathogenic mutations. Our study further validated the reliability of PGT-M utilizing linkage analysis as a means to prevent the transmission of genetic disorders to future generations, and offered valuable insights for multidisciplinary clinical practices on CVD.