To expand our assessment of the contribution of major structural rearrangements in the LDL receptor gene to the spectrum of mutations causing FH [8], we further studied, by MLPA analysis, 318 patients with an FH phenotype referred for molecular genetic analysis to Aarhus Sygehus, Aarhus University Hospital in the period January 1995 to June 2004, in whom no mutations in the LDL receptor gene had been detected by SSCP analysis and in whom the apoB R3500Q mutation also had been excluded. The gene discussed is APOB; the disease is familial hyperaldosteronism.