ALPL and hypophosphatasia: As not every pathogenic or rare ALPL variant leads to a manifestation of HPP, we propose that clinical suspicion of the disease characterized by bone complications and at least one additional complication concerning teeth, muscle, central nervous or mental system, and repeated low TNSALP or BAP together with high PLP levels should lead to the diagnosis of HPP if rare ALPL gene variants of ACMG class 4 or higher are found.