DNAH8 and familial hemiplegic migraine: However, CGRP infusion failed to induce migraine attack in patients affected by the familial hemiplegic migraine (FHM) with known mutations in the calcium channel, voltage-dependent, P/Q type, alpha 1A subunit, the ATPase, Na+/K+ transporting, alpha 2 (+) polypeptide genes or without known mutations [63].