Title:  Two cases of familial hypomagnesemia with hypercalciuria and nefrocalcinosis: dental findings

Abstract:  Background The authors describe dental and periodontal conditions of two Chinese sisters affected by familial hypomagnesemia with hypercalciuria and nefrocalcinosis (FHHNC). FHHNC is a rare syndrome, genetically investigated since 1999, transmitted as an autosomal recessive disease. It is related to a mutation of PCN-1 gene which encodes for a tight junction protein named paracellin. Case report Oral examination of two Chinese patients showed marked enamel hypoplasia, acute gingivitis and periodontal bone loss and severe malocclusion. The literature does not report previous investigations about the dental conditions of FHHNC patients. The syndrome is not definitely described from the clinical point of view. Conclusion Further researches are necessary to understand the linkage between bone loss and enamel structure anomalies in FHHNC and to discover the relationships between nefrocalcinosis, hypomagnesemia, hypercalciuria and amelogenesis imperfecta.