Evidence for both genetic and non-genetic etiologies exists.

Several families with hemifacial spasm have been reported, suggesting a genetic etiology or predisposition in some cases.

Other hypotheses of genetic etiology have also been formulated.

It is hoped that recent advancements in the genetic etiologies of common diseases will improve pharmaceutical development.

Huntington's disease, for example, has a concordance rate of 100%, indicating a predominately genetic etiology.

Let the search for genetic etiology go on, but there is no current scientific basis to accentuate a gender difference.

The following may help in determining a genetic etiology:

Because of this, it has complicated the exact explanation of the genetic etiology of the syndrome.

Endophenotypes, on the other hand, purport to identify potential behavioral markers that correlate with specific genetic etiology.

Very rare, this medical condition usually has a genetic or familial etiology.