Our findings indicate that the PD1.5 T allele is associated with a reduced risk of MM, showing a significantly lower risk in both codominant (RR = 0.56, 95%CL: 0.37–0.87) and dominant (RR = 0.73 95%CL: 0.59–0.90) models. This evidence concerns the gene PDCD1 and Miyoshi myopathy.