PRENATAL-DIAGNOSIS OF XERODERMA-PIGMENTOSUM AND COCKAYNE-SYNDROME

In a study of fetal cells from a series of 12 pregnancies in ten famil ies at risk for the ultraviolet light-sensitive, DNA repair-deficient diseases xeroderma pigmentosum (XP) and Cockayne syndrome (CS), we det ected one XP and two CS homozygote fetuses. The diagnoses were confirm ed by analysis of fetal skin fibroblasts or second amniotic samples af ter termination of the pregnancies. The measurement of ultraviolet lig ht sensitivity and DNA repair depended on properties common to the sev en excision repair-deficient XP complementation groups (A-G) and the t wo CS complementation groups (A, B). No XP variant families were inclu ded in the study, because the variant requires different testing techn iques. Reliable and rapid diagnosis proved possible in all but one of the 12 pregnancies, supporting the use of these methods until the spec trum of mutations in the various XP and CS genes of the U.S. populatio n is fully characterized and a DNA sequence-based diagnostic procedure becomes available.