Polymorphisms in a number of genes, including those coding for efflux ABC transporters (ABCB1 and ABCG2), influx transporter- organic anion–transporting polypeptide 1B1 (OATP1B1) (SLCO1B1) and Cytochrome P450 enzymes: CYP2D6, CYP3A4, and CYP3A5, have been associated with SAMS. This evidence concerns the gene SLCO1B1 and short stature-auditory canal atresia-mandibular hypoplasia-skeletal anomalies syndrome.