MOLECULAR ANALYSIS AND PRENATAL-DIAGNOSIS OF HUMAN FUMARASE DEFICIENCY

Fumarase deficiency is a rare autosomal recessive disorder of the citr ic acid cycle causing severe neurological impairment. The cDNA for bot h the rat and human enzymes has been cloned previously and shown to en code a coding region of 1.46kb, To scan for mutations in fumarase-defi cient patients we amplified the coding region of fumarase from fibrobl ast/lymphoblast cDNA employing the oligonucleotide primers designed fr om the published human and rat cDNA sequence. We then directly sequenc ed the polymerase chain reaction product. Zn seven unrelated patients, we detected four missense mutations (A265T, D383V, F269C, K187R), a n onsense mutation (W458X), a 3-bp AAA insertion that introduces an addi tional lysine residue at codon 435, and a spontaneous new mutation res ulting in a 74-bp deletion (66del74), Seven at-risk pregnancies were m onitored with one prenatal diagnosis of fumarase deficiency by molecul ar analysis and favorable outcome of the other pregnancies as predicte d by enzyme assay of cultured fetal cells or molecular analysis. (C) 1 998 Academic Press.