SALBUTAMOL TREATMENT IN A PATIENT WITH HYPERKALEMIC PERIODIC PARALYSIS DUE TO A MUTATION IN THE SKELETAL-MUSCLE SODIUM-CHANNEL GENE (SCN4A)

A 35 year old woman with clinical features of hyperkalaemic periodic p aralysis confirmed on provocative exercise testing was investigated. D NA sequence analysis of the gene for the a-subunit of the skeletal mus cle voltage gated sodium channel (SCN4A) on chromosome 17q23 identifie d a point mutation at nucleotide position 2188. This results in a thre onine to methionine substitution at amino acid position 704. The patie nt was intolerant of diuretic medication but showed a striking clinica l and electrophysiological improvement with salbutamol therapy. Treatm ent with P-adrenergic agents should be considered in patients with hyp erkalaemic periodic paralysis who are intolerant of, or resistant to, diuretic medications.