PREIMPLANTATION DIAGNOSIS OF AUTOSOMAL-DOMINANT RETINITIS PIGMENTOSUMUSING 2 SIMULTANEOUS SINGLE-CELL ASSAYS FOR A POINT MUTATION IN THE RHODOPSIN GENE

A couple requested preimplantation genetic analysis for a dominant for m of retinitis pigmentosum caused by a C-->A transversion in the rhodo psin gene. Since this point mutation does not alter a restriction endo nuclease site we designed two separate analytical systems, one involvi ng site-specific mutagenesis and the other involving allele-dependent length polymorphism. After establishing the accuracy and robustness of these assay systems we utilized both systems simultaneously in a hemi nested polymerase chain reaction (PCR) system. This allowed accurate p reimplantation diagnosis to be performed. One embryo was transferred b ut a pregnancy did not occur.