A G to A point mutation was introduced at position 572 in exon 4, resulting in a histidine substitution for arginine at amino acid 191. In addition, a loxP-flanked neomycin cassette was inserted downstream of exon 5. This mutation corresponds to c.584G>A, pArg195His in humans that is associated with the most severe forms of vanishing white matter. Cre-mediated recombination removed the floxed neomycin resistance cassette leaving the R191H mutation in exon 4. (J:234659)