Outcome of primary tubular tubulopathies diagnosed in pediatric age.

BACKGROUND AND OBJECTIVE: Primary tubulopathies are rare and usually present at pediatric age. Recent advances in genetic diagnosis and treatment have changed its natural history. This study provides the clinical spectrum of a series of primary tubulopathies diagnosed in a Pediatric Nephrology Unit and to offer long-term follow-up data regarding growth, estimated glomerular filtration (eGFR) and intercurrent complications. PATIENTS AND METHODS: Observational study in 53 patients with primary tubulopathies and identified genetic defect: Gitelman syndrome (36%), distal renal tubular acidosis (15%), cystinuria (11%), X-linked hypophosphatemic rickets (7%), Dent-syndrome Lowe (7%), cystinosis (6%), and 1-2 cases of other tubulopathies. Demographic, analytical and clinical data were collected at diagnosis, during evolution and at the time of the study. RESULTS: The age (median and interquartile range) at diagnosis was 5.08 years (1.33-8.50). The most frequent presentation manifestations were metabolic decompensations associated with intercurrent processes (40%) and short stature (38%). Height (mean ±â€¯SD) was -1.39 ±â€¯1.49 at diagnosis and 1.07 ±â€¯1.54 after a follow-up of 18.92 (6.25-24.33) years. Sixteen (32%) developed an eGFR <90 ml/min/1.73 m2. Three patients required replacement renal replacement. Eleven patients had metabolic decompensations that required hospitalization, 9 renal colic and/or kidney stones and 10 mental problems. Six of 8 patients with distal renal tubular acidosis developed sensorineural deafness. CONCLUSIONS: Primary tubulopathies are a heterogeneous group of diseases that cause growth impairment, largely reversible with treatment, risk of eGFR reduction and significant extrarenal complications derived or associated.