Objective: Mutation screening was performed on two Chinese families with HOKPP to locat the corresponding mutations and to specify the clinical features associated with the mutation.
Methods: Target-exon PCR and direct sequencing were used to screen mutation in the CACNA1S and SCN4A gene of all numbers of the two families. The clinical features of patients were summary.
Results: A heterozygous point mutation 2015G-->A causing R672H in the SCN4A was found in five patients and five normal relatives of the two families. Features of R672H mutation are incomplete penetrance, especially non-penetrance of phenotype in women and potassium is effective, but acetazolamide is not.
Conclusion: The SCN4A R672H mutation exists in the Chinese family with HOKPP.