Table 1.

Main characteristics of the four studies selected.

References	Title of manuscript	Cohort	Age	Methods	Main Findings
Yang et al. (11)	The nasal methylome and childhood atopic asthma	36 children with persistent atopic asthma 36 control subjects 1st validation 30 asthmatic children 36 control subjects 2nd validation 12 adults with atopic asthma 12 control subjects	10-12 years	Illumina Infinium Human Methylation450 BeadChips	119 DMRsa associated with 118 unique genes and 118 DMPsb associated with 107 unique genes.
Zhang et al. (12)	Nasal DNA methylation is associated with childhood asthma	29 sibling pairs discordant for asthma 54 sibling pairs for verification	Asthmatics 12.01 years No-Asthmatics 11.35 years	Illumina Infinium Human Methylation450 BeadChips	Three CpGsc associated with asthma (cg00112952, cg14830002, cg23602092).
Forno et al. (13)	DNA methylation in nasal epithelium, atopy, and atopic asthma in children: genome-wide study	483 Puerto Rican children 72 African American children 432 European children	9-20 years	Illumina Infinium Human Methylation450 BeadChips	30 top CpGsc in or near genes implicated in epithelial barrier function and in other genes involved in airway epithelial integrity and immunity
Cardenas et al. (14)	The nasal methylome as biomarker of asthma and airway inflammation in children	547 children	12.9 years	Infinium MethylationEPIC BeadChip	20 top differentially methylated CpGsc associated with current asthma

^aDifferentially methylated region (DMR).

^bDifferentially methylated probe (DMP).

^cCitosine-phosphate-guanine (CpGs).