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Genetically inherited endocrine disorder entity that
is clinically characterized by fatigue, ileus (from hypokalemia),
hypertension, strokes, and other significant cardiovascular events in young
persons because of overproduction of aldosterone.
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ACTH-Dependent Hyperaldosteronism
Syndrome.
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Type I: Aldosteronism Sensitive to Dexamethasone;
Glucocorticoid-Suppressible Hyperaldosteronism; Glucocorticoid-Remediable
Aldosteronism.
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Type II: Aldosteronism Insensitive to Dexamethasone; Glucocorticoid Nonsuppressible
Hyperaldosteronism; Glucocorticoid Nonremediable Aldosteronism.
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Fewer than 150 validated cases reported in the
literature.
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Autosomal dominant. The
glucocorticoid-sensitive form (type I) of familial hyperaldosteronism is
related to a chimeric gene product combining (by crossover) the promoter of
the 11β-hydroxylase gene with the coding region of the aldosterone
synthetase gene on chromosome 8q21 (anti-Lepore-type fusion of Cyp11B1 and
Cyp11B2). Type II is caused by a mutation in chromosome 7p22.
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Hyperaldosteronism is a consequence of
aldosterone-producing adenoma. The effects of aldosterone are mediated
through activation of the epithelial sodium channel, and activating
mutations of this channel lead to signs of mineralocorticoid excess.
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Hypertension, polyuria, polydipsia, fatigue, tinnitus,
paresthesia, and paralysis of variable duration (from 1 hour to weeks),
failure to thrive, and muscle loss. Laboratory investigations include
hypokalemia (<3.5 mmol/liter), metabolic alkalosis associated with
inappropriate kaliuresis, increased plasma levels of aldosterone (>40
ng/dl), decreased plasma renin activity (<0.3 ng/ ml/hour), and
nonsuppressible aldosterone response to ambulation. Dexamethasone test did
not suppress aldosterone level. Magnetic resonance imaging is better for locating the adenoma than
is CT. The left gland is four times more frequently involved
than the right gland. In Conn syndrome, the ratio of deoxycorticosterone to
corticosterone is unaffected by adrenocorticotropic hormone.
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The clinical presentation of familial
hyperaldosteronism is not distinctive, and diagnosis requires expertise on
the part of the physician. Familial hyperaldosteronism patients usually have
a long history of fatigue, muscle loss, paresthesia (even paralysis),
tinnitus, and headache (caused by hypertension). Polyuria and polydipsia are
common features. The main physical symptom is hypertension. It is not
unusual for the diagnosis to be established when a severe complication of
hypertension occurs (stroke, cardiac problem). Laboratory examinations
reveal hypokalemia (often severe), metabolic alkalosis, inappropriate
kaliuresis, decreased plasma rennin activity, and high basal plasma levels of
aldosterone. Imaging reveals either diffuse adrenocortical hyperplasia or
multiple adrenocortical adenomas. Depending on the efficacy of
glucocorticoid given to correct the symptomatology, two types of this
familial disease exist: type I, which is glucocorticoid sensitive and caused by
multiple adrenocortical adenomas, and type II, which is caused by adrenal
hyperplasia and is not glucocorticoid remediable. Otherwise the two forms
are clinically similar.
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Evaluate electrolytes status and
correct hypokalemia. Restrict sodium intake. Administrate spironolactone
(5-10 mg/kg/d)
. Stop captopril or enalapril 24 hours before general
anesthesia. Evaluate immune status because of treatment by agents that
inhibit angiotensin-converting enzyme.
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If hypokalemia has not been corrected
prior to anesthesia, hyperventilation could be dangerous by decreasing
further potassium plasma levels. Regional anesthesia technique such as
epidural anesthesia can be used safety in children, especially in patients
less than 8 years of age, because of the absence of induced ...