RESUMO
BACKGROUND: This article summarizes the varying clinical manifestations of three siblings with familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC) caused by the same genetic lesion. METHODS: The medical records of three siblings with FHHNC (one girl and two boys, aged 6 to 12 years) were reviewed and the clinical manifestations and treatment of their disease were described. RESULTS: Despite varying phenotypes, each sibling had the same genetic lesion-a novel homozygous mutation in CLDN16 (c.211A>G, M71V). CONCLUSION: Although FHHNC is a rare disorder, this report is significant for the following reasons: (i) it describes a novel CLDN16 mutation causing FHHNC, adding to the literature of FHHNC-causing CLDN16 mutations; (ii) it suggests that genes other than CLDN16 or epigenetic factors are involved in the clinical spectrum of FHHNC; and (iii) it reinforces the variability of disease manifestation and genotype-phenotype correlations.
