Neonatal hypophosphatasia and seizures. A case report.
Hypophosphatasia is a rare genetic disease characterized by deficiency of tissue-nonspecific alkaline phosphatase (TNSALP) activity, excessive urinary excretion of phosphoethanolamine, poor bone mineralization and skeletal anomalies. The shortage of alkaline phosphatase (ALP) alters the process of mineralization of skeleton causing a reduced transformation of phosphoethanolamine into phosphatidylethanolamine (cerebral phospholipid) with consequent high serum and urinary levels of phosphoethanolamine, a sensitive and highly specific marker for the disease. Four clinical forms have been described based on the age of onset with different courses and prognoses. An unusual case of lethal perinatal hypophosphatasia associated with seizures observed in a newborn admitted to Neonatal Intensive Care Unit of the University of Catania is described.