The diagnosis of the early infantile form of hypophosphatasia tarda.

The diagnostic characteristics of the early infantile form of hypophosphatasia tarda are demonstrated in a case of a first child of healthy, probably consanguineous, unmarried parents. The diagnosis of the disease is based on the clinical and radiographic findings. The absence of alkaline phosphatase activity in the blood serum and leukocytes, and the excretion of phosphorylethanolamine in urine confirm the diagnosis. The inheritance appears to be autosomal recessive.