Case report: birth of healthy twins after preimplantation genetic diagnosis of propionic acidemia.

PURPOSE: Development of an ad hoc protocol for the preimplantion genetic diagnosis of propionic acidemia in a couple carrying the mutations c.737G>T (G246V) and c.1218del14ins12 (ins/del) in the PCCB gene. Propionic acidemia is an autosomal recessive metabolic disorder where the body is unable to process certain parts of proteins and lipids. Symptoms manifest few days after birth and sometimes progress to more serious medical problems, including heart abnormalities, coma and death.

METHODS: Four short tandem repeat markers closely linked to the PCCB gene were tested, in order to support the direct mutation detection diagnosis. Multiplex fluorescent heminested polymerase chain reaction followed by fragment analysis and minisequencing was used.

RESULTS: Fourteen single blastomeres from nine embryos were tested and two carrier embryos were transferred, resulting in the birth of two healthy boys.

CONCLUSIONS: Preimplantation genetic diagnosis represents a valid reproductive option for couples affected of propionic acidemia, in order to avoid transmission to offspring.