<s>[INST] <<SYS>> This is a medical question of type : frequency <</SYS>> How many people are affected by 15q13.3 microdeletion ? [/INST] 15q13.3 microdeletion likely occurs in about 1 in 40,000 people in the general population. It appears to be more common in people with intellectual disability, epilepsy, schizophrenia, or autism spectrum disorders. </s>