<s>[INST] <<SYS>> This is a medical question of type : frequency <</SYS>> How many people are affected by progressive familial intrahepatic cholestasis ? [/INST] PFIC is estimated to affect 1 in 50,000 to 100,000 people worldwide. PFIC type 1 is much more common in the Inuit population of Greenland and the Old Order Amish population of the United States. </s>