Preimplantation Genetic Diagnosis for DEB by Detecting a Novel Family-Specific COL7A1 Mutation in Vietnam

Abstract

Background: Epidermolysis bullosa (EB) is a disorder characterized by the appearance of blisters, erosions and wounds in response to minimal trauma. The disease manifests with noticeable symptoms ranging from mild to severe, classified into four major types: epidermolysis bullosa simplex (EBS), junctional epidermolysis bullosa (JEB), dystrophic epidermolysis bullosa (DEB) and Kindler syndrome. Preimplantation genetic diagnosis for the disease remains the only available option for families at risk for the recurrence of the disorder without having to terminate an ongoing pregnancy. Materials and Methods: A novel COL7A1 mutation was used to design primers for the polymerase chain reaction (PCR) to amplify the segment spanning the mutation in the family and their in-vitro fertilization (IVF) embryos. Then, the PCR products were sequenced with Sanger sequencing to detect the alteration in the allele, and some embryos would go through NGS-based preimplantation screening for chromosomal abnormalities. Results: The established protocol for EB detected mutant allele in 6/9 embryos (66.6%), while the remaining 3 embryos (33.4%) appeared to not carry any mutation. Only one among 3 embryos was recommended to be transferred into the mother's uterus. Conclusion:The established preimplantation genetic diagnosis procedure is helpful to families affected by epidermolysis bullosa caused by COL7A1 mutations but wish to have healthy children.

Genetic counseling for pre-implantation genetic testing of monogenic disorders (PGT-M)

“…Based on the test results, the genetic counselor would guide the family and patients for follow-up tests which could be either in the prenatal or preimplantation period. (k) There are many disorders for which PGT-M was successfully offered (44)(45)(46).…”