SCRIPPS HOWARD NEWS SERVICE Researchers have identified a genetic variation that increases by 24 times the risk of a black baby in the United States succumbing to sudden infant death syndrome, or crib death. According to a report published Wednesday in the Journal of Clinical Investigation, about one in nine American blacks carries a copy of the variant gene, but children who carry two copies of the mutation face the increased risk. Overall, mutations in the gene, called SCN5A, were found in 5 percent of the 133 SIDS cases in black infants reviewed by scientists. And the researchers estimate that...