To date, mutations in five ABCA genes are causatively linked to monogenic recessive disorders: ABCA1 (Tangier disease), ABCA3 (neonatal surfactant deficiency), ABCA4 (Stargardt disease), ABCA12 (harlequin ichthyosis) and most recently ABCA5 was linked to congenital generalized hypertrichosis terminalis [21–25]. This evidence concerns the gene ABCA1 and Tangier disease.