LINKAGE OF THE APO-CIII MICROSATELLITE WITH ISOLATED LOW HIGH-DENSITY-LIPOPROTEIN CHOLESTEROL

To evaluate whether a highly polymorphic microsatellite region within intron 3 of the apolipoprotein (ape) CIII gene is linked to the isolat ed low HDL-C phenotype, we studied eight unrelated probands (mean HDL- C = 10 +/- 5 mg/dl) and 157 biological family members. After PCR ampli fication of genomic DNA and denaturing polyacrylamide gel electrophore sis, 26 alleles were identified in this microsatellite including 9 all eles heretofore unreported. Quantitative sib-pair linkage analysis dem onstrated strong evidence of linkage between the isolated low HDL-C ph enotype and the apo CIII microsatellite region (P = 0.007). The micros atellite was also linked to apo Al (P = 0.001), the primary apolipopro tein of HDLC. Therefore, this highly polymorphic microsatellite region is a potentially important marker in the genetic evaluation of the is olated low HDL-C phenotype.