Complex sentence: The most common underlying cause is one of several possible point mutations in the genes synthesising calcium or sodium ion channels in skeletal muscle; this mutation can be inherited either in an autosomally dominant or recessive manner.
Split into simpler sentences: The most common underlying cause is one of several possible point mutations in the genes synthesising calcium or sodium ion channels in skeletal muscle. This mutation can be inherited either in an autosomally dominant or recessive manner.