Using MF-PCR to diagnose multiple defects from single cells: implications for PGD

Single cell genetic analysis is generally performed using PCR and FISH. Unt il recently, FISH has been the method of choice. FISH however is expensive, has significant misdiagnosis rates, can result in interpretation difficult ies and is labour intensive making it unsuitable for high throughput proces sing. Recently fluorescent PCR reliability has increased to levels at or su rpassing FISH whilst maintaining low cost. However, PCR accuracy has been a concern due to allelic dropout. Multiplex PCR can now increase accuracy by using multiple markers for each chromosome to firstly provide diagnosis if markers fail and,or secondly confirm diagnosis. We compare a variety of di agnostic methods and demonstrate for the first time a multiplex PCR system providing simultaneous diagnosis and confirmation of the major aneuploidy c hromosomes (21, 18, 13) and sex as well as DNA fingerprint in single cells. We also discuss the implications of using PCR for aneuploidy screening in preimplantation genetic diagnosis. (C) 2001 Elsevier Science Ireland Ltd. A ll rights reserved.