SNPs in the CpG island of NAP1L2: a possible link between DNA methylation and neural tube defects?
Deletion of the murine X-linked Nap1l2 gene causes lethality from midgestation onwards. The affected embryos exhibit neural tube defects (NTDs) closely resembling spina bifida and anencephaly in humans. X-linked familial and spontaneous cases of NTD were analyzed for sequence alterations in the human NAP1L2. No differences were found in the familial cases. However, a number of single nucleotide polymorphisms (SNPs) within the 5' region of NAP1L2 were identified both in cases of spontaneous NTD and in normal controls. Most of these SNPs lead to the replacement of guanidines or cytosines within a CpG island that is conserved between the human and the mouse promoter regions. Demethylation in vitro activates Nap1l2 transcriptional activity, suggesting the importance of the CpG island in regulating the activity of the Nap1l2/NAP1L2 genes, and the potential importance of the polymorphisms in modifying their transcriptional activity. NAP1L2/Nap1l2 expression may therefore depend on the genetic-environmental factors that are frequently associated with NTDs.
Unité Génétique Moléculaire Murine, CNRS 1947, Institut Pasteur, Paris, France. urogner@pasteur.fr
Ute Christine
UC
Rogner
Patrick
P
Danoy
Fumihiko
F
Matsuda
Gudrun Elizabeth
GE
Moore
Philip
P
Stanier
Philip
P
Avner
D000818:Animals; D001374:Azacitidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D002460:Cell Line; D018899:CpG Islands / Q000235:genetics*; D004247:DNA / Q000737:chemistry / Q000235:genetics; D019175:DNA Methylation; D015254:DNA Modification Methylases / Q000037:antagonists & inhibitors; D004252:DNA Mutational Analysis; D000077209:Decitabine; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D008040:Genetic Linkage; D006801:Humans; D007763:Lac Operon / Q000235:genetics; D008297:Male; D051379:Mice; D009419:Nerve Tissue Proteins / Q000235:genetics*; D009436:Neural Tube Defects / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic / Q000235:genetics; D011506:Proteins / Q000235:genetics*; D014960:X Chromosome / Q000235:genetics
D004791:Enzyme Inhibitors; C466114:NAP1L2 protein, human; C466113:Nap1l2 protein, mouse; D009419:Nerve Tissue Proteins; D011506:Proteins; D000077209:Decitabine; D004247:DNA; D015254:DNA Modification Methylases; D001374:Azacitidine