N.M. ZAIKOVA¹, S.L. MOROZOV^1, 2, M.P. SAFONOVA²

 ¹Pirogov Russian National Research Medical University, Moscow

²Veltischev Research and Clinical Institute for Pediatrics and Pediatric Surgery of the Pirogov Russian National Research Medical University, Moscow

Contact details:

Morozov S.L. — PhD (Medicine), Leading Researcher of the Department of Hereditary and Acquired Kidney Diseases named after Prof. M.S. Ignatova, Associate Professor of the Department of Hospital Pediatrics No. 2

Address: 2 Taldomskaya St., 125412 Moscow, Russian Federation, tel.: +7-903-138-77-32, e-mail: mser@list.ru

Familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC) is a rare autosomal recessive tubulopathy caused by mutations in the CLDN16 or CLDN19 genes encoding the tight junction proteins claudin16 and claudin19. These proteins play a pivotal role in paracellular magnesium and calcium transport in the thick ascending limb of the loop of Henle and are responsible for the majority of tubular magnesium reabsorption. FHHNC is characterized by hypomagnesemia, hypercalciuria, medullary nephrocalcinosis and often ocular involvement, and it usually progresses to chronic kidney disease requiring renal replacement therapy in young adulthood. We report a case of rapidly progressive decline in renal function in a girl with biallelic CLDN19 mutations and no ocular involvement.

Key words: CLDN16, CLDN19, hypomagnesemia, hypercalcemia, nephrocalcinosis

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