First preimplantation genetic testing case for monogenic disease in Latvia.

Huntington's disease (HD) is fatal neurodegenerative disease caused by a (CAG) triplet repeat expansion in the Huntingtin (HTT) gene. Inheritance pattern of the disease is autosomal dominant and onset depending on triplet repeat count. Transgenerational HD transmission can be avoided by preimplantation genetic diagnosis (PGD). Here, we report the first preimplantation genetic testing case for monogenic disease, in Latvia. The result of our work led to the birth of healthy child with normal HTT alleles in his genome. We describe a PGD strategy and testing algorithm that can be applied to any couple at risk of transmitting monogenic disease.