Background <p>Dent disease is a hereditary kidney tubular disorder caused by pathogenic variants in either the <i>CLCN5</i> (Dent disease 1) or <i>OCRL1</i> (Dent disease 2) genes. As a rare genetic disorder, Dent disease often presents with variable clinical manifestations, leading to frequent misdiagnosis or underdiagnosis, especially in milder cases. Consequently, limited research has addressed the long-term clinical outcomes of Dent disease.</p> Methods <p>This retrospective multicenter cohort study was conducted at 9 hospitals in Korea. A total of 48 male patients from 44 unrelated families with genetically confirmed Dent disease were enrolled, and their clinical phenotypes, and genetic backgrounds were assessed.</p> Result <p>The median age at diagnosis for Dent disease was 6.8 years, and 42 patients were diagnosed with Dent disease 1. At diagnosis, 17 patients (37.0%) demonstrated the classic triad of Dent disease features, whereas 12 patients (26.1%) presented solely with isolated low-molecular-weight proteinuria. During follow-up, whereas all patients maintained low-molecular-weight proteinuria, hypercalciuria, nephrocalcinosis, and nephrolithiasis occurred in 82.6%, 56.5%, and 8.3% of patients, respectively. The cases with Dent disease 2 had a higher rate of hypophosphatemia and significant proteinuria compared to Dent disease 1. A negative correlation was identified between hypercalciuria and age in the overall Dent disease cohort. The decline rate of annual estimated glomerular filtration rate was 0.6 mL/min/1.73 m², without the case of kidney failure. At last follow-up, kidney dysfunction was present in 39.5% of cases.</p> Conclusions <p>Due to its rarity and phenotype variability, Dent disease is frequently under-recognized by clinicians. As over one-third of patients progress to chronic kidney disease by early adulthood, a high index of clinical suspicion and early genetic testing are essential, alongside rigorous monitoring of kidney function.</p> Graphical abstract <p></p>