Etiologies And Short-Term Outcome of Medullary Nephrocalcinosis in Children
Journal of Pediatric Nephrology,
Vol. 13 (2025),
12 May 2026,
https://doi.org/10.22037/jpn.v13i1.52033
Background and Aim:
Hypercalciuria, hyperoxaluria, hereditary renal tubular disorders, and drug intoxication are the etiologies of nephrocalcinosis in children. This study was conducted to determine the etiologies and short-outcome (resolution rate) of nephrocalcinosis.
Methods
Children aged ≤18 years old with nephrocalcinosis who were referred to the nephrology clinic of an academic center from March 2003 to 2019 were considered for the study. Measurement of serum creatinine, sodium, potassium, calcium, phosphorous, blood gas analysis and random or 24-hour urine samplings for creatinine and calcium levels were the inclusion criteria.
Results
Of 49 cases, 43 met the inclusion criteria. They included 21 girls (48.8%). The median age of patients was two years (10 months - eight years). They followed up for a median of 9 months (1-34 months). Medullary nephrocalcinosis grades III, II, and I were reported in nine (20.9%), one (2.3%), and 33(76.8%) patients, respectively. The etiologies of nephrocalcinosis were unknown (41.8%), idiopathic hypercalciuria (34.9%), idiopathic hyperoxaluria (18.6%), distal RTA (9.3%). Hypophosphatemic rickets, Dent disease, and Bartter syndrome were found each in one patient. Seven cases (16.3%) had mixed abnormalities. Resolution of nephrocalcinosis at a follow-up of ≥ six months was uncommon (19.2%). The median weight-for-age Z score at presentation was -0.8 which reached to -0.36 at the last follow-up (P =0.011).
Conclusion
We found idiopathic hypercalciuria and idiopathic hyperoxaluria as the most common identified etiologies, respectively. Hereditary tubular disorders accounted for 16.3% of the cases. Resolution of nephrocalcinosis was uncommon even in nephrocalcinosis grades I, at a follow-up of ≥ six months.
Keywords: Medullary nephrocalcinosis; Hypercalciuria; Hyperoxaluria; Distal RTA; Outcome