This variant was found in an individual with familial hypobetalipoproteinemia as part of a compound heterozygote with G661A and with a background of homozygosity for ApoE2. It was also seen in 4/100 controls. The authors cite Rehberg et al where the variant is found to have no in vitro effect, and Berthier et al. where it is found with a frequency of 18.3% in French-Canadians with seemingly no effect. They hypothesize that with a ApoE2 background a slight in vivo change may cause expression of the disease.