<s>[INST] <<SYS>> This is a medical question of type : frequency <</SYS>> How many people are affected by congenital hypothyroidism ? [/INST] Congenital hypothyroidism affects an estimated 1 in 2,000 to 4,000 newborns. For reasons that remain unclear, congenital hypothyroidism affects more than twice as many females as males. </s>