Defective aldosterone synthesis associated with hyperkalemic periodic paralysis.

Abstract

OBJECTIVE:

To describe defective aldosterone biosynthesis (corticosterone methyl oxidase type II [CMO-II] deficiency) in a kindred with hyperkalemic periodic paralysis.

SETTING:

Tertiary care hospital in Madison, Wis.

PATIENTS:

Individuals studied included a female infant with failure to thrive, hyponatremia, and hyperkalemia; the infant's asymptomatic mother and father; and a maternal aunt and grandmother with hyperkalemic periodic paralysis.

INTERVENTIONS:

Mineralocorticoid synthetic pathways were analyzed with synthetic adrenocorticotropin stimulation. In one patient with hyperkalemic periodic paralysis, acetazolamide sodium therapy was discontinued and replaced with fludrocortisone acetate therapy.

MEASUREMENTS/MAIN RESULTS:

Impaired aldosterone synthesis with marked accumulation of mineralocorticoid precursors 18-hydroxycorticosterone and corticosterone indicated severe CMO-II deficiency in the infant. In her relatives and parents, baseline aldosterone levels (74 to 111 pmol/L) were low (reference range, 194 to 830 pmol/L, a nonstricted sodium diet). Serum 18-hydroxycorticosterone levels (442 to 1021 pmol/L) were normal (reference range, 138 to 1270 pmol/L), but ratios of 18-hydroxycorticosterone to aldosterone were abnormally elevated (4.5 to 13.7; reference range, 2.65 +/- 1.86), indicating deficient CMO-II enzyme activity. Acetazolamide therapy was substituted with fludrocortisone therapy in the maternal aunt without return of paralytic symptoms.

CONCLUSION:

This association of hyperkalemic periodic paralysis with CMO-II deficiency and resolution of paralytic episodes with fludrocortisone therapy suggests a contribution of defective mineralocorticoid-mediated potassium homeostasis to the pathogenesis of hyperkalemic periodic paralysis.

• Authors: D B Allen
• Journal: Archives of neurology (Arch Neurol) Vol. 50 Issue 3 Pg. 325-8 (Mar 1993) ISSN: 0003-9942 [Print] United States
• PMID: 8442715 (Publication Type: Case Reports, Journal Article)

Chemical References

• Aldosterone
• Mixed Function Oxygenases
• Cytochrome P-450 CYP11B2
• corticosterone methyl oxidase II

Topics

• Aldosterone (deficiency)
• Cytochrome P-450 CYP11B2
• Female
• Humans
• Hyperkalemia (complications, metabolism)
• Infant
• Mixed Function Oxygenases (deficiency)
• Paralysis (complications, metabolism)