<s>[INST] <<SYS>> This is a medical question of type : frequency <</SYS>> How many people are affected by 1p36 deletion syndrome ? [/INST] 1p36 deletion syndrome is believed to affect between 1 in 5,000 and 1 in 10,000 newborns. However, this may be an underestimate because some affected individuals are likely never diagnosed. </s>