AMH and Klinefelter syndrome: However, significantly lower median values of serum AMH were observed between the negative (median [IQR]: 1.7 [0.8; 4.7]) and positive (median [IQR]: 8 [3; 13]) sperm retrieval groups for individuals with NOA related to non-mosaic Klinefelter syndrome (p = 0.01) (Fig. 3a; Table 4).