title: A novel mutation of the claudin 16 gene in familial hypomagnesemia with hypercalciuria and nephrocalcinosis mimicking rickets.
abstract: Familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC) is caused by a mutation in the gene CLDN16, which encodes paracellin 1 (claudin-16), atight junction protein mediating paracellular transport which is expressed in the thick ascending loop of Henle and in the distal convoluted tubule, where reabsorption of magnesium occurs. We present a 4 years old Turkish female child with a chief complaint of hypocalcemic tetany. A diagnosis of FHHNC was confirmed by genetic testing for a mutation in claudin 16 gene. Claudin 16 gene revealed homozygosity for the p.K183E(AAA>GAA) C. 547A>G indicating the diagnosis of hypomagnesemia with hypercalciuria and nephrocalcinosis. To our knowledge, this is the first case of FHHNC reported in Turkish population diagnosed at molecular level.
authors.affiliation: Division of Pediatric Nutrition and Metabolism, Department of Paediatrics, Gazi University Hospital, Ankara, Turkey. cskasapkara@gmail.com
authors.forename: C S
authors.initials: CS
authors.lastname: Kasapkara
authors.forename: L
authors.initials: L
authors.lastname: Tumer
authors.forename: I
authors.initials: I
authors.lastname: Okur
authors.forename: A
authors.initials: A
authors.lastname: Hasanoglu
mesh_terms: D002675:Child, Preschool; D057167:Claudins; D003937:Diagnosis, Differential; D005260:Female; D006720:Homozygote; D006801:Humans; D053565:Hypercalciuria / Q000175:diagnosis / Q000235:genetics*; D008565:Membrane Proteins / Q000235:genetics*; D009154:Mutation; D009397:Nephrocalcinosis / Q000175:diagnosis / Q000235:genetics*; D010641:Phenotype; D015499:Renal Tubular Transport, Inborn Errors / Q000175:diagnosis / Q000235:genetics*; D012279:Rickets / Q000175:diagnosis; D014421:Turkey
chemical_list: D057167:Claudins; D008565:Membrane Proteins; C502010:claudin 16