<s>[INST] <<SYS>> This is a medical question of type : frequency <</SYS>> How many people are affected by PRICKLE1-related progressive myoclonus epilepsy with ataxia ? [/INST] The prevalence of PRICKLE1-related progressive myoclonus epilepsy with ataxia is unknown. The condition has been reported in three large families from Jordan and northern Israel and in at least two unrelated individuals. </s>