Gordon syndrome

　　1. Etiology

　　It is generally believed that the disease is caused by congenital renal tubular dysfunction, with increased renal sodium reabsorption leading to elevated blood sodium and chloride levels, causing blood volume expansion and hypertension. Renin secretion is suppressed, resulting in decreased plasma renin activity. Due to reduced potassium excretion by the kidneys, hyperkalemia occurs. Acidosis is mainly caused by hyperkalemia.

　　2. Pathogenesis

　　Gordon et al. believe that the possible mechanism of this disease is the increased reabsorption of sodium and chloride in the renal tubules, which leads to increased volume and suppression of renin and aldosterone secretion. Additionally, the reduced reabsorption of filtered sodium in the distal tubule results in decreased excretion of potassium and hydrogen ions. Under the condition of suppressed renin-angiotensin system, the level of aldosterone is still not enough to maintain potassium balance. Low-salt diet and diuretic therapy achieve good results. The strong pressor response of angiotensin II and norepinephrine to cold stimulation supports the existence of volume expansion. Schambelan et al. believe that the disease may be due to the destruction of the chloride reabsorption barrier in the distal tubule, where chloride is reabsorbed with sodium, unable to establish the necessary potential difference for excretion of potassium and hydrogen ions, resulting in hyperkalemia, hyperchloremia, and acidosis. Farfel et al. propose a functional defect in the cell membrane, considering the dysfunction of potassium entering the cell. Kelmm believes that low levels of prostaglandin (PGE2) are one of the pathophysiological mechanisms of Gordon syndrome. This disease is a genetically heterogeneous disease, and O’Shaughnessy et al. believe that it is related to abnormalities in chromosome 17. The three loci, chromosome 1 (PHA2A), 17 (PHA2B), and 12 (PHA2C), have been confirmed. However, NaCl (SLCl2A3) sensitive to thiazides has been excluded from the relationship with the disease.

　　The complications of Gordon syndrome are similar to those of hypertension, and can include stroke, left ventricular failure, hypertensive retinopathy, hypertensive nephropathy, left ventricular hypertrophy, slowly progressive arteriosclerosis, malignant arteriosclerosis, chronic renal failure, and so on.

　　Patients often have tolerance to chronic hyperkalemia. In severe cases of hyperkalemia, this disease may have muscle weakness or paralysis. Sometimes, the T wave on the electrocardiogram is明显. A few cases also show short stature and intellectual disability.

　　The main manifestations of Gordon syndrome are hyperkalemia, hyperchloremia, acidosis, low renin, and hypertension.

　　According to Achard, by 2001, at least 90 cases of Gordon syndrome had been reported worldwide, with varying degrees of severity and different clinical manifestations. One group of 69 cases reported included 37 with hypertension, 15 with short stature, 4 with intellectual disability, 37% of those under 20 years of age had hypertension, and 82% of those over 20 years of age had hypertension. Another group reported 51 cases of Gordon syndrome from 1964 to 1991, with patients coming from the United States (17 cases), Australia (8 cases), Israel (7 cases), Finland (4 cases), Japan (6 cases), Scotland (3 cases), Canada (3 cases), France (2 cases), 28 males and 23 females, with onset age ranging from birth to 52 years, mostly between 10 to 30 years old, 34 out of 44 with family history, 38 with hypertension, blood pressure ranging from 140 to 220/90 to 120 mmHg, blood sodium level 134 to 144 mmol/L; blood potassium level 4.9 to 9.6 mmol/L, mostly 5.6 to 8.0 mmol/L; blood chloride level 102 to 119 mmol/L; HCO3- 14 to 31 mmol/L (mostly 16 to 20 mmol/L); plasma and urine aldosterone are generally normal or slightly low; blood creatinine is generally normal; atrial natriuretic peptide is mostly normal, and plasma renin activity (PRA) was measured in some cases, with a lower level of PRA. A salt-restricted diet can correct the above disorders. Abnormalities of the incisors are occasionally seen, and strokes may also occur due to hypertension. A 48-year-old male patient reported in Shanghai had a blood pressure of 140 to 170/90 to 105 mmHg, blood potassium level of 5.8 to 6.1 mmol/L, and blood chloride level of 112 to 117 mmol/L. After a salt-restricted diet, the above abnormalities were significantly improved.

　　This disease is a rare autosomal dominant genetic disorder, and there is currently no effective preventive method. In the diagnosis and treatment of hypertension, one should be vigilant about the existence of this disease, and further examination should be carried out when suspicious signs are found, in order to discover and treat it early, as the prognosis of this disease is relatively good. The biochemical disorder of Gordon syndrome begins at birth, while hypertension occurs slightly later. Hypertension is rare in childhood and more common in adulthood, and the prognosis depends on the blood pressure level. The complications of patients treated with thiazide diuretics are fewer than those of patients with common hypertension, and the lifespan of the former is often normal.

　　1. Hyperkalemia is a clue and basic condition for the diagnosis of the disease, and blood potassium should be checked multiple times.

　　2. Hyperchloremic acidosis, in most cases, plasma bicarbonate concentration decreases, and arterial blood pH also decreases.

　　3. Plasma renin activity is significantly reduced, and plasma aldosterone levels are mostly normal levels, but compared to the standard of normal blood potassium levels, the standard for high blood potassium levels is low, and atrial natriuretic peptide is normal or slightly elevated.

　　4. Blood creatinine, blood urea nitrogen, and endogenous creatinine clearance rate, which reflect renal function, are often within the normal range, and urine concentration function is normal.

　　Sodium-restricted diet or thiazide diuretic therapy can improve or correct blood pressure and electrolyte disorders.

　　1. Foods suitable for Gordon syndrome

　　Maintain a balanced diet, eat more high-fiber foods such as fruits and vegetables, eat more high-protein foods such as eggs and soybeans, pay attention to a light diet, and engage in moderate exercise. Pay attention to a high-sugar, high-fat diet to ensure sufficient calories and reduce the potassium released during the body's catabolic metabolism.

　　2. Foods to avoid in Gordon syndrome

　　Avoid smoking, drinking, spicy food, coffee, strong tea, and other刺激性 foods, and avoid eating bananas and other foods rich in potassium.

　　1. Treatment

　　Thiazide diuretics are very effective in treating Gordon syndrome. They can lower blood pressure to normal levels, correct hyperkalemia, hyperchloridemia, and acidosis, and even small doses of diuretics can cause hypokalemia and alkalosis due to low blood chloride. Long-term use may, but is not common, produce hyperuricemia, hyperglycemia, and hypercalcemia. It is recommended to start with a low dose of diuretics and adjust the dose of treatment according to changes in blood pressure and blood potassium and chloride levels.

　　A sodium-restricted diet also achieves good therapeutic effects, which can improve hyperkalemia and hyperchloridemia.

　　2. Prognosis

　　Gordon syndrome biochemical disorder begins at birth, while hypertension occurs slightly later. Hypertension is rare in childhood and more common in adulthood. Prognosis depends on blood pressure levels. Patients with good responses to thiazide diuretics have fewer complications than those with ordinary hypertension and often have a normal lifespan.