The commonest genetic cause of cholesteryl ester storage disease is an exon 8 splice junction variant in the LIPA gene (rs116928232, c.894G>A; E8SJM) previously found to have an allele frequency of 0.0011 (1 in 450 individuals) in a large European population.
Mutational analysis of the patient's blood showed the homozygous G-->A mutation at position -1 of the exon 8 splice donor site (E8SJM-allele) known for adult cholesteryl ester storage disease (CESD); the polymorphic background was that of the complex haplotype -6Thr, 2Gly, 894 G-->A.
A splice junction mutation causes deletion of a 72-base exon from the mRNA for lysosomal acid lipase in a patient with cholesteryl ester storage disease.