Symptoms include loss of vision, epilepsy (see entry Epilepsy syndromes in Childhood) and progressive loss of abilities, including walking, eating and talking. Sadly, to date there is no cure for any type of Batten disease. A number of different genetic types are known. In the UK, CLN2 (late infantile) and CLN3 (juvenile) are the most common:
- CLN1 disease, infantile: onset usually between six months and two years with developmental delay and seizures
- CLN2 disease, late infantile: onset between two and four years with seizures and slowing down of developmental progress
- variant late infantile forms (CLN5, 6, 7, 8 diseases): onset between two and six years, often with challenging behaviour, slowed developmental progress and then seizures
- CLN3 disease, juvenile: onset of deteriorating vision between five and nine years. Children remain healthy for several years but sadly, death can occur at any time from the late teens to the mid-thirties
- CLN4 disease (and others) adult: onset normally before the age of 40 years. Shortened life expectancy.