First gene therapy for Tay-Sachs disease successfully given to two children

Two babies have received the first-ever gene therapy for Tay-Sachs disease after over 14 years of development.

Tay-Sachs is a severe neurological disease caused by a deficiency in an enzyme called HexA. This enzyme breaks down a fatlike substance that normally exists in very small, harmless amounts in the brain. Without HexA, however, this fatlike substance can accumulate to toxic levels that damage and kill neurons.