<s>[INST] <<SYS>> This is a medical question of type : frequency <</SYS>> How many people are affected by beta-ureidopropionase deficiency ? [/INST] The prevalence of beta-ureidopropionase deficiency is unknown. A small number of affected individuals from populations around the world have been described in the medical literature. In Japan, the prevalence of beta-ureidopropionase deficiency has been estimated as 1 in 6,000 people. Researchers suggest that in many affected individuals with absent or mild neurological problems, the condition may never be diagnosed. </s>