Birth of two healthy females after preimplantation genetic diagnosis for familial amyloid polyneuropathy.

Familial amyloid polyneuropathy (FAP), Portuguese type, is a late onset, high penetrance, autosomal dominant Mendelian disorder caused by a V30M substitution in the transthyretin (TTR) protein. A genetic diagnosis was developed using fluorescent single cell polymerase chain reaction (PCR) on lymphocytes from patients and controls. Ovarian stimulation and oocyte retrieval were carried out using conventional protocols in a couple in whom the female was heterozygous for the mutation TTR V30M. Blastomere biopsy was performed on day 3 after intracytoplasmic sperm injection. PCR was then performed for a segment of the TTR gene encompassing the V30M mutation. The transfer of three embryos at day 4 resulted in a twin pregnancy, confirmed as healthy females by amniocentesis at 16 weeks of gestation; the birth took place at 37 weeks of gestation. With this report, FAP, TTR related, joins the lengthening list of genetic conditions for which preimplantation genetic diagnosis has been successfully carried out.