Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an important cause of hemolytic anemia worldwide. Severely affected patients have chronic hemolysis with exacerbations following oxidative stress. Mutations causing severe chronic non-spherocytic hemolytic anemia (CNSHA) commonly cluster in Exon 10, a region important for protein dimerization. An African-American male presented at age 2 weeks with pallor and jaundice, and was found to have hemolytic anemia with G6PD deficiency. His severe clinical course was inconsistent with the expected G6PD A− variant. DNA sequencing revealed two common mutations (A−) and a third novel Exon 10 mutation. This inherited haplotype represents a novel triple G6PD coding mutation causing chronic hemolysis. Pediatr Blood Cancer 2008;51:816–819. © 2008 Wiley-Liss, Inc.