Renal tubular acidosis: Varied aetiologies and clinical presentations: Three case reports

Table 1 Summary of the cases of renal tubular acidosis

Case	Age (years)/sex	Presenting complaint	Significant medical history	Lab findings	Imaging findings	Genetic testing	Diagnosis	Therapy
1	30/F	Pain, redness around right eye, swelling on cheek, mucopurulent discharge from nose, dental caries	Consanguineous parentage, developmental delay, severe intellectual impairment, recurrent fractures, hypokalemic periodic paresis since childhood	Hypokalemia, hyperchloremic metabolic acidosis, normal anion gap, alkaline urine pH	Osteopetrosis in radiographs of the skull and limbs, basal ganglia calcification in CT scan	Homozygous deletion variant in intron 3 of CA 2 gene	Proximal RTA (type 2)	Oral sodium bicarbonate and potassium citrate
2	56/M	Progressive weakness in limbs, femur neck fracture, thoracolumbar spine compression fractures	Proximal muscle weakness, inability to walk without support	Hypokalemia, elevated creatinine and urea, hyperchloremic metabolic acidosis, normal anion gap	Bilateral medullary nephrocalcinosis on kidney ultrasound	Heterozygous missense mutation in TRP6 gene suggestive of FSGS 2	Distal RTA (type 1)	Oral potassium citrate, right femur fracture fixation, denosumab
3	54/M	Quadriparesis, acute urinary retention	Recurrent episodes of hypokalemic quadriparesis	Hypokalemia, hyperchloremic metabolic acidosis, alkaline urine pH, Normal anion gap, Thyrotoxicosis, Elevated TSH receptor antibody, normal ANA, Elevated FBS and HbA1C	On ultrasound diffuse enlargement of thyroid with normal vascularity. Technetium 99 (99mTc) thyroid scintigraphy showed uniformly increased uptake in both lobes, 16.2% (normal 0.3%-3%), consistent with Graves’ disease	Nil	Distal RTA secondary to Graves’ disease	Oral sodium bicarbonate and potassium citrate for distal RTA. For Graves’ disease carbimazole, propranolol followed by radio-iodine ablation

CT: Computed tomography; CA 2: Carbonic anhydrase type 2; RTA: Renal tubular acidosis; FSGS: Focal segmental glomerulosclerosis; ANA: Antinuclear antibody; FBS: Fasting blood sugar; HbA1C: Hemoglobin A1C or glycated hemoglobin.