Evidence from AD-PHP-Ib patients as well as mouse models indicates that the expression levels of the two transcripts, EXON A/B and GNAS, are oppositely regulated in cis. On the maternal allele methylation across EXON A/B inhibits expression of the ncRNA, while the downstream GNAS promoter drives the expression of the coding RNA (Liu et al., 2000a,b). This evidence concerns the gene GNAS and Alzheimer disease.