Pregnancies by PGD for Translocation Carriers Using Single Interphase Cell FISH with Chromosome-Specific Breakpoint Spanning Probes

Authors: Man Li, David L Hill, Michael Vermesh♦, Kevin Winslow*, Dunson Yang*, Mark Surrey. ART Reproductive Center, Beverly Hills, Ca 90210, ♦18370 Burbank Blvd, #301, Tarzana, Ca 91356 *Florida Institutes for Reproductive Medicine, Jacksonville, Florida 32207

Introduction: 2 couples with multiple miscarriages were referred for PGD following diagnosis of the reciprocal translocation in the male partners: 46, XY t (2,7)(p11.2;q22.1) and 46, XY t(2,7)(p23.1;p22.1).

Objective: Using single interphase cell FISH with chromosome-specific breakpoint spanning probes PGD to assist translocation carriers to have babies.

Materials and Methods: Before PGD, lymphocytes were used to test the efficiency of the probes. Sperm were analyzed by FISH using the same probe sets to predict the chromosome status of the embryos. Embryo biopsies were performed on Day 3 after fertilization. Single blastomeres were biopsied. Embryo biopsy of case 1 was done by ART personnel in Dr. Vermesh’s IVF lab. Embryo biopsy of case 2 was done by Dr. Yang in Florida and slides were shipped to ART for translocation diagnosis. Chromosome-specific breakpoint spanning probes were used in FISH. Three embryos were transferred in both cases.

Conclusion: using single interphase blastomere FISH for translocation carriers by breakpoint spanning probes can help patients have phenotypically normal offspring.