Bilateral nephrocalcinosis: an unusual presentation in early childhood with PKHD1 biallelic inheritance

Abstract

Background: Nephrocalcinosis (NC) is characterized by an excessive accumulation of calcium deposits in the kidneys. In children, it is often incidentally discovered with an uncertain prognosis. Case-diagnosis/treatment: A 3-month-old girl suspected to have a milk protein allergy underwent an abdominal ultrasound that revealed increased echogenicity in the renal pyramids. Over the course of a 5-year follow-up, her kidneys maintained size within the upper limits, and echographies suggested medical nephropathy. By age 6, imaging findings were consistent with medullary NC. Further analysis identified PKHD1variants, which required bioinformatic tools to guide diagnosis. Until the age of 7, her kidney function has remained intact; however, her prognosis is uncertain. Conclusions: NC in newborns is rare, but its incidence is rising. Recurrent urinary infections or kidney stones may lead to kidney failure. A proactive approach in sporadic NC enables an early diagnosis to orientate nephrological supervision and facilitates counseling to support family planning decisions.