Low utilization of prenatal and pre-implantation genetic diagnosis in Huntington disease - risk discounting in preventive genetics.

Huntington disease (HD) is a late-onset, fatal neurodegenerative disorder caused by a (CAG) triplet repeat expansion in the Huntingtin gene that enlarges during male meiosis. In 1996 in this journal, one of us (J. D. S.) presented a methodology to perform pre-implantation genetic diagnosis in families at-risk for HD without revealing the genetic status of the at-risk parent. Despite the introduction of accurate prenatal and pre-implantation genetic testing which can prevent transmission of the abnormal HD gene in the family permanently, utilization of these options is extremely low. In this article, we examine the decision-making process regarding genetic testing in families with HD and discuss the possible reasons for the low uptake among this group.