Fanconi syndrome: report of a case

A 59-year-old female patient was admitted because of muscle weakness in all four limbs for a period of 5 days. She had been found to have Graves' disease 4 years ago previous to this, and had received a subtotal thyroidectomy 1 year later. Hypothyroidism supervened and she had been receiving levothyroxine replacement in recent years. She also had non-insulin-dependent diabetes, which was controlled with diet only. During the 5 days prior to admission, she developed muscle weakness which finally worsened to complete paralysis of all four limbs. Physical examination showed tenderness and weakness of the extremity muscles. Abnormal laboratory data included serum K, 1.6 mEq/L; P, 1.2 mg/dl; uric acid, 1.6 mg/dl; fasting glucose, 267 mg/dl; T3, 36.65 ng/dl; T4, 4.0 micrograms/dl; TSH, 5.35 mu u/ml; free T4, 0.57 ng/dl; and metabolic acidosis with pH, 7.298; PCO2, 27.0 mmHg; and HCO3, 12.8 mEq/L. An EKG showed a prominent U wave, and urinalysis revealed renal glucosuria and massive aminoaciduria. An oral sodium bicarbonate loading test showed an increasing loss of bicarbonate through the urine, while the plasma bicarbonate level was elevated. Clinical manifestations improved after the administration of sodium bicarbonate, potassium chloride and neutral phosphate.