Molecular Testing for Preimplantation Genetic Diagnosis of Single Gene Disorders

Preimplantation genetic testing has evolved tremendously from the early days of FISH detection for a select few chromosome aneuploidies to now combining the detection of all whole chromosome imbalances in conjunction with single gene disorder testing for inherited diseases. As universal carrier screening and exome or genome studies become more commonplace, more and more families are becoming interested in reducing the risk of having a child with a severe disease using preimplantation genetic testing. We describe here the use of quantitative PCR (qPCR) for the custom construction of single gene disorder testing plans for families, the validation of the probes designed, and the protocol for diagnosing an embryo biopsy. qPCR has been shown to have the lowest risk of failed amplification and allele dropout and thus the lowest risk of a misdiagnosis, while also currently providing the fastest protocol to allow for rapid turnaround of results.