SAT-720 Severe Skeletal Sequelae of Long-Standing Distal Renal Tubular Acidosis in Two Filipino Male Patients

Abstract Disclosure: J.U. Borlagdan: None. P. Dela Peña: None. B.R. Balanquit: None. J.L. Manuel: None. Distal renal tubular acidosis (dRTA) is a rare inherited disorder characterized by the nephron’s failure to acidify urine, leading to normal anion-gap metabolic acidosis. When left uncorrected, chronic acidosis promotes bone mineral resorption, resulting in significant skeletal complications. This report presents two cases of Filipino male patients with intractable hypokalemia, normal anion-gap metabolic acidosis with a positive urine anion gap, and hypocalcemia, ultimately leading to growth failure, progressive height loss, and skeletal deformities.Case 1 describes a 20-year-old male with persistent hypokalemia, growth stunting, bone deformities, and delayed puberty since childhood. Despite correction of serum potassium and bicarbonate levels with potassium citrate and calcium/vitamin D supplementation, he exhibited continued growth delay and bone deformities at follow-up. Case 2 involves a 36-year-old male with chronic hypokalemia, progressive height loss of 79% (from 165 cm to 131 cm), disabling bone pain, scoliosis, and contracture deformities. His history revealed years of inadequate treatment with potassium chloride alone. Diagnostic findings confirmed dRTA, and management with potassium citrate was initiated.dRTA results from defects in acid excretion, either due to primary genetic mutations or secondary conditions such as autoimmune diseases or nephrotoxins. The chronic acidotic state shifts bone metabolism toward resorption through increased RANKL activity and suppressed osteoblastic function, predisposing patients to osteomalacia, fractures, and growth failure. Unlike other renal osteodystrophies, dRTA-induced bone disease is acidosis-dependent and preventable with early intervention.Both cases highlight the importance of timely diagnosis and proper management, particularly in suspected hereditary dRTA. Alkali therapy with potassium citrate is the cornerstone of treatment, effectively reversing metabolic acidosis and preventing nephrolithiasis. However, long-term mismanagement, as seen in these patients, can lead to irreversible skeletal damage. Early intervention is crucial to prevent debilitating complications, underscoring the necessity for increased awareness and appropriate treatment strategies. Keywords: distal renal tubular acidosis, growth failure, skeletal sequelae, metabolic acidosis, hypokalemia Presentation: Saturday, July 12, 2025