Accuracy of preimplantation diagnosis of single-gene disorders by polar body analysis of oocytes.

Abstract

A number of pitfalls in single-cell DNA analysis, including undetected DNA contamination, undetected allele drop out, and preferential amplification, may lead to misdiagnosis in preimplantation genetic diagnosis of single-gene disorders. Preimplantation genetic diagnosis was performed by sequential first and second polar body analysis of oocytes in 26 couples at risk for having children with various single-gene disorders. Mutant genes were amplified simultaneously with linked polymorphic markers, and only embryos resulting from the mutation-free oocytes predicted by polar body analysis with confirmation by polymorphic marker testing were transferred back to patients. Overall 529 oocytes from 48 clinical cycles (26 patients) were tested, resulting in the transfer of 106 embryos in 44 clinical cycles. As many as 46 (9.6%) instances of allele dropout were observed, the majority (96%) of which were detected. Seventeen unaffected pregnancies were established, of which nine resulted in the birth of an unaffected child, and the rest are ongoing. A high accuracy of preimplantation genetic diagnosis of single-gene disorders is achieved by application of sequential analysis of the first and second polar body and multiplex polymerase chain reaction.