How is batten disease inherited?

Answer 1

Batten disease is a group of disorders known as neuronal ceroid lipofuscinoses or NCLs. Over 400 different errors (mutations) in 14 different segments of DNA (genes) can lead to one of 14 forms of Batten disease. Symptoms associated with the disease are very similar. Each form differs primarily by when symptoms appear. Children with unhealthy CLN1 genes develop infantile Batten around 1 year old. Children with unhealthy CLN2 genes show symptoms at age 4. Children with unhealthy CLN3 genes show symptoms at age 6, etc.

We each have 2 copies of every gene, one from each parent. To inherit one of the childhood forms of Batten, we need to receive the unhealthy gene from both parents so that we have 2 copies but neither works. Our parents are OK because they each have 1 healthy copy (that does all of the work) and an unhealthy copy. Every child of two parents who "carry" bad genes, has a 25% chance of developing Batten.

Each form affects the nervous system resulting in blindness (except adults), seizures, movement disorders, altered thought (psychoses), cognitive decline and early death.