Familial autosomal dominant dopa responsive Parkinson's disease in three living generations showing extreme anticipation and childhood onset.

We describe a three generation family with Parkinson's disease showing autosomal dominant inheritance with extreme anticipation. Familial Parkinson's disease in three living generations is extremely rare, and anticipation is an unusual and interesting feature. Anticipation was shown in all generations and may have involved previous generations. Some cases of familial Parkinson's disease may therefore involve a trinucleotide repeat gene as part of the causal mechanism.