CLINICAL-APPLICATION OF PREIMPLANTATION DIAGNOSIS FOR MYOTONIC-DYSTROPHY

Myotonic dystrophy (DM) or Steinert's disease is a progressive autosom al dominant disease characterized by increasing muscle weakness, myoto nia, cataracts, and endocrine abnormalities such as diabetes and testi cular atrophy. The gene for DM was cloned in 1992 and the mutation was shown to be an expanded trinucleotide (CTG) repeat. A polymerase chai n reaction (PCR)-based assay was described soon after that would allow (prenatal) diagnosis of the disease. Based on these PCR assays, we ha ve developed a method for carrying out single-cell PCR for DM. In prei mplantation diagnosis, embryos obtained in vitro are checked for the p resence or absence of a disease, after which only embryos shown to be free of the disease under consideration are returned to the mother. A single-cell assay was developed for preimplantation diagnosis in coupl es where one of the parents is afflicted with DM. Twenty intracytoplas mic sperm injection (ICSI) cycles were carried out in eight patients a nd between one and four embryos were replaced in 17 out of 20 cycles. Two of the patients became pregnant and have had prenatal diagnosis wh ich has confirmed that they are unaffected. (C) 1997 by John Wiley & S ons, Ltd.