A RARE CASE OF FAILURE TO THRIVE IN INFANTS: MALIGNANT INFANTILE OSTEOPETROSIS.

Background: Malignant infantile osteopetrosis (MIOP) is a rare autosomal recessive bone disease, characterized by reduced or dysregulated osteoclastic activity and increased bone mass. Major consequences include bone marrow failure and nerve compression. Chronic anemia, feeding problems caused by bulbar nerve involvement and recurrent infections as well as bone growth in diameter and not length leads to failure to thrive (delayed growth, weight gain, and development), seen in many osteopetrotic children. The pericentric inversion of chromosome 9 is the most frequently found in general population and has a role in abnormal phenotype development. Material and methods: Case report of a 6 months old boy with 3 admissions, first at the age of three months for hypocalcemic seizures. Based on the dysmorphic phenotype,presence of anemia, severe hypocalcemia, hepatosplenomegaly, failure to thrive, mental retardation, ventriculomegaly, optic nerve atrophy and the typical radiological images diagnose of MIOP complicated by rickets was established. Failure to thrive was defined based on persistent weight and waist below the 5th percentile. Genetic evaluation for chromosome abnormalities revealed apericentric inversion of chromosome 9. Conclusions: MIOP is a rare disease which can present with nonspecific symptoms; therefore it has to be considered in case of craniofacial bones abnormalities, severe hypocalcemia, anemia and early onset failure to thrive. The association of osteopetrosis complicated by rickets and chromosome 9 inversion led in our case to severe dysmorphic features and severe growth restriction. [ABSTRACT FROM AUTHOR]