RT Journal Article SR Electronic T1 Malignant infantile osteopetrosis presenting with neonatal hypocalcaemia JF Archives of Disease in Childhood - Fetal and Neonatal Edition JO Arch Dis Child Fetal Neonatal Ed FD BMJ Publishing Group Ltd and Royal College of Paediatrics and Child Health SP F21 OP F23 DO 10.1136/fn.83.1.F21 VO 83 IS 1 A1 Srinivasan, Madhusudan A1 Abinun, Mario A1 Cant, Andrew J A1 Tan, Kelvin A1 Oakhill, Anthony A1 Steward, Colin G YR 2000 UL http://fn.bmj.com/content/83/1/F21.abstract AB Presentation characteristics were reviewed in 14 children from 12 families with malignant infantile osteopetrosis seen at two large referral centres for bone marrow transplantation. Children from six of these families presented initially with symptoms of hypocalcaemia. These comprised early or late neonatal convulsions in six cases (corrected serum calcium < 1.5 mmol/l), and vomiting and irritability (serum calcium 1.68 mmol/l) in another. One other related child had severe and persistent jittering episodes almost certainly attributable to hypocalcaemia. In seven of eight cases, these symptoms developed during the first 14 days of life. Although occasionally reported previously, malignant infantile osteopetrosis remains essentially unrecognised as a cause of neonatal hypocalcaemia, often resulting in diagnostic confusion and delay. This is important in the context of curative haemopoietic stem cell transplantation where preservation of sight may depend on early intervention.