ESPN 51th Annual Meeting

ESPN 2018


 
Prenatal hyperechogenic kidneys in three cases of Infantile Idiopathic Hypercalcemia associated with SLC34A1 mutations
HUREAUX MARGUERITE 2 MOLIN ARNAUD 3 JAY NADINE 4 SALIOU ANNE HéLèNE 5 SPAGGIARI EMMANUEL 7 SALOMON RéMI 6 BENACHI ALEXANDRA 7 VARGAS-POUSSOU ROSA 2 HEIDET LAURENCE 1

1- CENTRE DE RéFéRENCE DES MALADIES RéNALES HéRéDITAIRES DE L’ENFANT ET DE L’ADULTE (MARHEA), ASSISTANCE PUBLIQUE HôPITAUX DE PARIS, PARIS, FRANCE
2- DéPARTEMENT DE GéNéTIQUE, ASSISTANCE PUBLIQUE HôPITAUX DE PARIS, HôPITAL EUROPéEN GEORGES POMPIDOU, PARIS FRANCE
3- SERVICE DE GéNéTIQUE, CENTRE HOSPITALIER UNIVERSITAIRE DE CAEN, CAEN, FRANCE
4- CENTRE HOSPITALIER UNIVERSITAIRE DE BREST, SERVICE DE PéDIATRIE ET GéNéTIQUE MéDICALE, BREST, FRANCE
5- CENTRE PLURIDISCIPLINAIRE DE DIAGNOSTIC PRéNATAL, CHRU, BREST, FRANCE
6- DéPARTEMENT DE NéPHROLOGIE PéDIATRIQUE, ASSISTANCE PUBLIQUE HôPITAUX DE PARIS, HôPITAL NECKER – ENFANTS MALADES, PARIS, FRANCE
7- DéPARTEMENT DE GYNéCOLOGIE-OBSTéTRIQUE, ASSISTANCE PUBLIQUE HôPITAUX DE PARIS, HôPITAL ANTOINE-BéCLèRE, UNIVERSITé PARIS-SUD, CLAMART, FRANCE
 
Introduction:

Prenatal diagnosis of hyperechogenic kidneys is associated with a wide range of etiologies and prognosis. The recent advances in fetal ultrasound associated with the development of next generation sequencing for molecular analysis have enlarged the spectrum of etiologies, making antenatal diagnosis a very challenging discipline. Of the various known causes of hyperechogenic fetal kidneys, Calcium and Phosphate metabolism disorders represent a rare cause. An accurate diagnosis is crucial for providing appropriate genetic counselling and medical follow up after birth. 

 

Material and methods:

We report on three cases of fetal hyperechogenic kidneys corresponding to postnatal diagnosis of nephrocalcinosis. In all cases, antenatal ultrasound showed hyperechogenic kidneys of normal to high size from 22 gestational weeks, with a normal amount of amniotic fluid. Postnatal ultrasound follow-up showed nephrocalcinosis associated with hypercalcemia, hypercalciuria, elevated 1,25(OH)2 Vitamin D, and suppressed parathyroid hormone levels. 

 

Results:

Molecular genetic analysis by next generation sequencing performed after birth in the three newborns revealed biallelic pathogenic variants in the SLC34A1 gene, encoding the Sodium/Phosphate cotransporter type 2 (NaPiIIa), confirming the diagnosis of Infantile Idiopathic Hypercalcemia. 

 

Conclusions:

Nephrocalcinosis due to Infantile Idiopathic Hypercalcemia can be a cause of fetal hyperechogenic kidneys, which suggests early antenatal anomaly of phosphocalcic metabolism. This entity should be considered in differential diagnosis. Postnatal follow-up of infants with hyperechogenic kidneys should include evaluation of phosphocalcic metabolism.