Glucocorticoid remediable aldosteronism also describable as aldosterone synthase hyperactivity, is an autosomal dominant disorder in which the increase in aldosterone secretion produced by ACTH is no longer transient.
Feedback by aldosterone concentration itself is of a non-morphological character (that is, other than changes in cell number or structure) and is relatively poor so that electrolyte feedback predominates in the short term.[citation needed]
Pathophysiology
The genes encoding aldosterone synthase and 11β-hydroxylase are 95% identical and are close together on chromosome 8. In individuals with GRA, there is unequal crossing over so that the 5' regulatory region of the 11-hydroxylase gene is fused to the coding region of the aldosterone synthase.[citation needed]
Although in normal subjects, ACTH accelerates the first step of aldosterone synthesis, ACTH normally has no effect on the activity of aldosterone synthase. However, in subjects with glucocorticoid-remediable aldosteronism, ACTH increases the activity of existing aldosterone synthase, resulting in an abnormally high rate of aldosterone synthesis and hyperaldosteronism.[4]
Diagnosis
Genetic testing is done to ascertain that the individual in question does indeed have the condition[5]
^Vonend O, Altenhenne C, Büchner NJ, et al. (April 2007). "A German family with glucocorticoid-remediable aldosteronism". Nephrol. Dial. Transplant. 22 (4): 1123–30. doi:10.1093/ndt/gfl706. PMID 17277347.