Use of single nucleotide polymorphism microarrays to distinguish between balanced and normal chromosomes in embryos from a translocation carrier

Objective: To prove the ability to distinguish between balanced and normal chromosomes in embryos from a translocation carrier.

Design: Case report.

Setting: Academic center for reproductive medicine.

Patient(s): Woman with a balanced translocation causing Alagille syndrome seeking preimplantation genetic diagnosis (PGD).

Intervention(s): Blastocyst biopsy for PGD.

Main outcome measure(s): Consistency of 3 methods of embryo genetic analysis (real-time polymerase chain reaction, single nucleotide polymorphism [SNP] microarray, and fluorescence in situ hybridization [FISH]) and normalcy in the newborn derived from PGD.

Result(s): PGD was applied to 48 embryos. Real-time polymerase chain reaction, SNP microarray, and FISH demonstrated 100% consistency, although FISH failed to detect aneuploidies observed by comprehensive SNP microarray-based analyses. Two blastocysts were identified to be normal for all 3 factors using SNP microarray technology alone. The 2 normal embryos were transferred back to the patient, resulting in the delivery of a healthy boy with a normal karyotype.

Conclusion(s): This is the first report of validation and successful clinical application of microarray-based PGD to distinguish between balanced and normal chromosomes in embryos from a translocation carrier.