ABCA1 and Tangier disease: Several groups simultaneously reported that pathogenic variants in the ABCA1 gene were the molecular basis of Tangier disease, a recessive orphan disease characterized clinically by hepato-splenomegaly, enlarged tonsils, described pathologically as lipid-laden macrophages and lymphoid tissues, a progressive peripheral neuropathy, and represented biochemically by an absence of HDL-C in the blood [9,10,11,12,13].