<s>[INST] <<SYS>> This is a medical question of type : frequency <</SYS>> How many people are affected by long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency ? [/INST] The incidence of LCHAD deficiency is unknown. One estimate, based on a Finnish population, indicates that 1 in 62,000 pregnancies is affected by this disorder. In the United States, the incidence is probably much lower. </s>