PRENATAL DETERMINATION OF GENOTYPES KELL AND CELLANO IN AT-RISK PREGNANCIES

OBJECTIVE: To evaluate the accuracy of a DNA-based testing methodology in determining the KEL1 and KEL2 (Kell and Cellano) genotype of fetus es at risk for Kell or Cellano hemolytic disease. STUDY DESIGN: DNA te as extracted from chorionic virus samples (CVS) or amniotic fluid (AF) cells, a portion of the Kell gene was amplified, the amplified produc t was cut with a restriction enzyme that recognizes the KEL1 nucleotid e substitution, and the digested product was run on a polyacrylamide g el to separate the fragments. This analysis was routinely run On uncul tured cells to provide rapid results. Testing of parental DNA was perf ormed in con junction with fetal analysis to ensure that their alleles were detectable with this DNA test.RESULTS: We determined the fetal K EL1 and KEL2 genotype in 1 CVS and 65 AF specimens. Forty-eight of the m were determined to be KEL2, 17 were KEL1/2, and was KEL1. Among the fetuses born to date, follow-up information was available on 14 of the m, 11 KEL2 and 3 KEL1/2. In all 14 there was complete correlation betw een the DNA analysis and the serotype or clinical course. CONCLUSION: Determination of the fetal KEL1 and KEL2 genotype using this DNA-based method provides accurate and timely information that can aid the pren atal care of women sensitized to these Kell antigens.