NLRP7 and familial hemiplegic migraine: Although FHM associated with NLRP7 mutations is inherited in an autosomal recessive manner, in contrast to ZFP57 mutation, homozygotes have normal genomic methylation but in female homozygotes there is a failure to establish methylation imprints in their germ cells leading to hydatidiform moles and reproductive wastage (male homozygotes do not have imprinting defects in their sperm).