COMPLEMENTATION GROUP ASSIGNMENTS IN FANCONI-ANEMIA FIBROBLAST CELL-LINES FROM NORTH-AMERICA

Fanconi anemia is a rare autosomal recessive disease characterized by developmental defects of the thumb and radius, childhood onset of panc ytopenic anemia and increased risk of leukemia. At least five compleme ntation groups (A-E) have been defined but only the FAC gene has been cloned. Cells can be assigned to complementation group C by direct mut ation analysis. To facilitate the search for additional FA genes and t o measure the frequency of complementation groups, we have established new genetically marked immortalized FA-A and FA-D fibroblast cell lin es and show their usefulness as universal fusion donors. These referen ce FA cell lines facilitated somatic cell fusion analysis and enabeled us to assign the complementation group in 16 unrelated FA patients fr om North America, The majority of patients, belong to FA complementati on group A (69%), followed by FA-C (18%), FA-D (4%) and FA-B or FA-E ( 9%).