More African Americans Have Low-LDL Gene Mutations

A study, reported on-line in NatureGenetics (January 16, 2005), found that 2genetic mutations that are common inindividuals of African descent are linkedwith a 50% reduction in low-densitylipoprotein (LDL) cholesterol. Earlier studiesinvolving mice showed that othermutations in the gene PCSK9 cause highcholesterol levels with raised LDL levels.To determine if there might be PCSK9variations that have the opposite effect,researchers examined the deoxyribonucleicacid sequence of PCSK9 in 128adults (half were African American) withlow LDL levels.

The results of the study indicated thatmutations in PCSK9 were shown in 2% ofAfrican Americans, but in <0.1% of EuropeanAmericans. The findings alsoshowed that carriers of the variant geneshad significantly lower LDL and total cholesterollevels, compared with noncarriers.Based on the study's results, the researchersnoted that the genetic mutationsidentified are "the most common sequencevariants yet described to have large effectson plasma cholesterol levels."