This paper implicates mutations in ABCG5 and ABCG8 as causing sitosterolemia. Out of 37 families, one US family case is reported to be compound heterozygous for this variant and a nonsense mutation (Gln172X). All families were found to have mutations in either ABCG5 or ABCG8, strong evidence for both genes is presented.
The evidence for this particular variant is weak. The variant was not seen in controls, which included 69 US individuals and 95 Finnish individuals. Assuming these caucasian controls can be combined, this is case+: 1, case-: 36, case+: 0, case-: 164. This gives p=0.18 with two-tailed fisher’s exact test.