We present the case of a patient with clinical features of
familial dysbetalipoproteinaemia (FD) including high
levels of total cholesterol, hypertriglyceridaemia and
the presence of palmar xanthomas. Whereas genotype
analysis identified the APOE3E3 isoform, sequence analysis revealed the presence of one APOE1 allele due to a mutation, p.Lys164Glu, which leads to loss of function of apolipoprotein E (ApoE), a rare cause of dominant FD.