Gordon's syndrome is a rare autosomal dominant disease that manifests in childhood. It is characterized by hypertension, hyperkalemic hyperchloremic metabolic acidosis, low renin and usually normal aldosterone levels, and it is sensitive to thiazide diuretics. A 20-year-old male with a history of diagnosed Gordon's syndrome was referred to a nephrology clinic for evaluation. The patient, who was under treatment with hydrochlorothiazide, had been diagnosed with Gordon's syndrome at the age of 11, when he presented hypertension and episodes of hyperkalemic hyperchloremic metabolic acidosis. However, none of his relatives had been diagnosed with this syndrome. Therefore, we assume that our patient might be a case of de novo gene mutation.