Moreover, low bone mass was also seen in the adults in the National Institutes of Health cohort with biallelic ENPP1 deficiency, who all met criteria for osteopenia or osteoporosis in at least one site—two patients were osteopenic (T-score between −1.0 and −2.5) in the distal radius and total hip, and one patient each had osteopenia and osteoporosis (T-score of −2.5 or lower) at the femoral neck (57) (Figure 4e). Here, ENPP1 is linked to Osteopenia.