On average, 1 in 30 individuals of Ashkenazi ancestry is a carrier of the FD gene.

Our body depends on our genes and we inherit two copies of  each  gene, one from  each parent. Carriers of an autosomal recessive  genetic disease such as FD, have one  normal copy of the  responsible gene and one mutated  copy. Carriers  do  not manifest the  disease, but  when  two carriers have  children, there  is a 25% chance of having a  child with that  disease.