Preimplantation genetic diagnosis (PGD) for extremes—successful birth after PGD for a consanguineous couple carrying an identical balanced reciprocal translocation

Objective

To report a healthy birth after preimplantation genetic diagnosis (PGD) performed for a consanguineous couple carrying an identical familial reciprocal translocation in both partners.

Design

Case report.

Setting

In vitro fertilization (IVF) clinic and genetic laboratory in a private hospital.

Patient(s)

Consanguineous couple carrying the same balanced reciprocal translocation: 46,XX,t(1;16)(q12;q11.2) and 46,XY,t(1;16)(q12;q11.2).

Intervention(s)

25 oocyte–cumulus complexes were retrieved 36 hours after human chorionic gonadotropin injection; metaphase II oocytes were fertilized by intracytoplasmic sperm injection; single blastomere biopsy was performed on 15 embryos on day 3; one embryo was found to be normal or balanced according to fluorescent in situ hybridization studies, embryo transfer was performed on day 4.

Main Outcome Measure(s)

Healthy birth of homozygous double translocation carrier twins with 46,XY,t(1;16)(q12;q11.2)mat,t(1;16)(q12;q11.2)pat karyotype.

Result(s)

Healthy monozygotic male twins were born at 36 weeks of gestation. Karyotype studies of the babies revealed that they are double translocation homozygotes: 46,XY,t(1;16)(q12;q11.2)mat,t(1;16)(q12;q11.2)pat. They are healthy and more than 4 years old later show no physical or mental abnormalities.

Conclusion(s)

To our knowledge, this is the first PGD study performed for a couple who carry the same reciprocal translocation. The twins born after this study are rare examples in the literature of healthy balanced reciprocal translocation homozygotes.

Key Words: Consanguinity, double translocation homozygosity, FISH, monozygotic dichorionic diamniotic twin, PGD, reciprocal translocation