CYP2D6*144 is assigned no function based on limited evidence. CYP2D6*144 is defined by a splice accepter variant predicting abberant splicing. A subject sequenced as CYP2D6*143/*144 had a risperidone/9-hydroxy-risperidone ratio that was higher (indicating lower activity) compared to that found in subjects with two no function alleles. Two subjects genotyped as *1/*144 and *2/*144 had ratios comparable to that of subjects with an AS of 1 (33998274). Therefore, consensus among experts was no function.