Apparent mineralocorticoid excess
Apparent mineralocorticoid excess Definition
Apparent mineralocorticoid excess (AME) is a potentially fatal genetic disorder and autosomal recessive cause of hypokalaemia, prenatal and postnatal growth failure, undetectable levels of aldosterone and renin and hypertension, which responds to treatments using glucocorticoid. Apparent mineralocorticoid excess is an extremely rare disorder, accounting to only 60 patients recorded for the past 20 years. Apparent mineralocorticoid excess is a result of mutations of the HSD11B2 gene, which is responsible for encoding the kidney isozyme ?11B-hydroxysteroid dehydrogenase?. This isozyme inactivates the circulating cortisol to the less-active metabolite cortisone, which leads to an elevated amount of cortisol in the kidney. Note that high concentrations of cortisol could activate the ?mineralocorticoid receptor?, which leads to an aldosterone-like effect in the patient's kidneys. This occurrence causes hypernatremia, hypokalemia and hypertension. Apparent mineralocorticoid excess can also be caused by licorice ingestion, which blocks 11-hydroxysteroid dehydrogenase and increase cortisol activity. Early and aggressive treatment of Apparent mineralocorticoid excess can prevent and improve the mortality and morbidity of end-organ damage rates. Diagnosis is made by DNA and hormonal analysis.
Apparent mineralocorticoid excess Symptoms and Signs
Apparent mineralocorticoid excess can be seen after birth with low birth weight and postnatal failure to thrive. Most patients of AME experience hypertension, polydipsia and persistent polyuria. AME is characterized by hyporeninemia, hypokalemic alkalosis and undetectable serum concentrations of ?aldosterone?. Majority of Apparent mineralocorticoid excess patients develop hypertension even at a young age. End-organ damages can also occur in the heart, retina, kidney or central nervous system.
Apparent mineralocorticoid excess Treatment
Treatment for Apparent mineralocorticoid excess is primarily focused in correcting hypertension and hypokalemia. Doctors recommend the MR receptor antagonist spironolactone as medication to protect receptors against excessive mineralocorticoid. Reduction in supplemental potassium and dietary sodium is usually instructed. AME patients with ?nephrocalcinosis? may require thiazide diuretic. Anti-hypertensive drugs, such as amiloride and thiazides may be helpful as the disease progresses.