Fanconi anaemia is an autosomal recessive disease for which four known
complementation groups exist. Recently, the gene defective in complem
entation group C (FACC) has been cloned. In order to determine the fra
ction of Fanconi anaemia caused by FACC mutations, we used reverse tra
nscription PCR and chemical mismatch cleavage (CMC) to examine the FAC
C cDNA in 17 FA cell lines. 4/17 patients (23.5%) had mutations in thi
s gene. Two Ashkenazi-Jewish individuals were homozygous for an identi
cal splice mutation. Three additional Jewish patients bearing this all
ele were found upon screening 21 other families. We conclude that a co
mmon mutation in FACC accounts for the majority of Fanconi anaemia in
Ashkenazi-Jewish families.