Gordon’s Syndrome is a rare genetic disorder affecting the body’s ability to regulate sodium and potassium levels. This condition primarily manifests as high blood pressure and elevated potassium concentrations in the blood. It is a lifelong condition that requires consistent management.
What is Gordon’s Syndrome?
Gordon’s Syndrome is formally known as Pseudohypoaldosteronism Type II (PHAII) or Familial Hyperkalemic Hypertension. This rare inherited disorder is characterized by persistent hypertension and hyperkalemia. Despite these electrolyte imbalances, kidney function generally remains normal.
The condition is a salt-sensitive form of hypertension, meaning a high-salt diet can worsen blood pressure. While its exact prevalence is unknown due to its rarity, it primarily follows an autosomal dominant inheritance pattern, meaning only one affected parent is needed to pass the condition to their children, with a 50% chance for each child. Some cases can also be inherited in an autosomal recessive manner, requiring two copies of the mutated gene.
Causes and Clinical Features
Gordon’s Syndrome is caused by genetic mutations that primarily affect the kidneys’ electrolyte balance. Mutations in genes like WNK1, WNK4, KLHL3, and CUL3 are involved. These genes regulate the activity of salt-transporting proteins in the kidneys, particularly the sodium chloride cotransporter (NCC).
These mutations lead to overactivity or accumulation of WNK-kinase 4, which increases the reabsorption of sodium and chloride in the distal renal tubule. This enhanced reabsorption of salt and water by the kidneys contributes to increased blood volume and, subsequently, hypertension. Reduced sodium delivery to more distant parts of the kidney tubule also affects potassium excretion, leading to elevated potassium levels.
Individuals with Gordon’s Syndrome often experience early-onset hypertension, though it can develop later in life. Hyperkalemia is a consistent finding, and it can sometimes lead to symptoms such as muscle weakness or fatigue, though potassium levels are not always high enough to cause serious problems. Another feature is hyperchloremic metabolic acidosis (elevated chloride and excess acid in the blood). Some patients may also experience hypercalciuria (increased calcium in the urine), which can contribute to kidney stone formation.
Identifying and Treating the Condition
Diagnosing Gordon’s Syndrome involves clinical observations and laboratory tests. A healthcare provider will look for hypertension and hyperkalemia in a patient with otherwise normal kidney function. Blood tests reveal elevated potassium levels, hyperchloremia, and metabolic acidosis. Plasma renin activity is often low or suppressed, and aldosterone levels are typically low or low-normal, which is unusual given the high potassium levels.
Genetic testing for mutations in the WNK1, WNK4, KLHL3, and CUL3 genes confirms the diagnosis. A thiazide challenge test can also assess kidney tubule function. Prompt diagnosis is beneficial, as the condition responds well to treatment.
The primary treatment for Gordon’s Syndrome is thiazide diuretics, such as hydrochlorothiazide. These medications inhibit the overactive sodium chloride cotransporter in the kidneys, helping the body excrete excess salt and water. This action reduces blood pressure and promotes potassium excretion, correcting electrolyte imbalances. Thiazide diuretics are effective in managing both hypertension and hyperkalemia, often normalizing blood pressure and electrolyte levels within a week. Dietary sodium restriction is also recommended to support treatment, and in some cases, a low-potassium diet may be considered.
Outlook and Patient Support
The prognosis for individuals with Gordon’s Syndrome is favorable with appropriate diagnosis and consistent treatment. The syndrome’s clinical features are mild, and overall kidney function is rarely affected long-term. With proper management, individuals can expect a normal life expectancy and quality of life.
Lifelong management and monitoring are crucial for sustained control of blood pressure and electrolyte levels. This involves regular check-ups, including routine measurements of electrolytes and blood pressure. Patient support groups and resources can play a role for affected individuals and their families, offering valuable information and a sense of community.