Study of the rare and low frequency variants in the Saguenay-Lac-Saint-Jean population

The Saguenay–Lac-Saint-Jean (SLSJ) region is located in northeastern Quebec and is known for its unique demographic history and founder effect. Since founder populations are enriched with population-specific variants, we characterized the variants distribution in SLSJ and compared it with four European populations (Finnish, Sweden, United Kingdom and France), of which the Finnish population is another founder population. Targeted sequencing of the coding and non-coding immune regulatory regions of the SLSJ asthma familial cohort and the four European populations were performed. Rare and low-frequency coding and noncoding regulatory variants identified in the SLSJ population were then investigated for variant- and gene-level associations with asthma and allergy related-traits (eosinophil percentage, immunoglobulin (Ig)E levels and lung function). Our data showed that (1) rare or deleterious variants were not enriched in the two founder populations as compared to the three non-founder European populations; (2) a larger proportion of founder population-specific variants occurred with higher frequencies; and (3) low-frequency variants appeared to be more deleterious. Furthermore, a rare variant, rs1386931, located in the 3’UTR of CXCR6 and intron of FYCO1 was found to be associated with eosinophil percentage. Gene-based analyses identified NRP2, MRPL44 and SERPINE2 to be associated with various asthma and allergy related traits. Our study demonstrated the usefulness of using a founder population to identify new genes associated with asthma and allergy-related traits; thus better understand the genes and pathways implicated in pathophysiology.

Type: Other
Archiver: European Genome-Phenome Archive (EGA)

3 Datasets 1 Publication

Click on a Dataset ID in the table below to learn more, and to find out who to contact about access to these data

Dataset ID	Description	Technology	Samples
EGAD00001004268	Samples from 149 trios from the Saguenay-Lac-Saint-Jean asthma familial cohort were all sequenced using a custom capture panel developed by our group, followed by next-generation sequencing. This custom capture panel covers around 3% of the genome, including coding and non-coding immune regulatory regions. We inferred the sequence in the non-sequenced siblings who were part of the same families as the trios and we imputed the sequence using IMPUTE2 in the whole cohort.		1214
EGAD00010001593	This dataset includes raw data (.idat) for the Illumina Human450k beadchip and methylation levels (.txt files). Methylation level were treated for normalization and background substraction. We removed probes with at least one of the following characteristics: (1) weak signal (pâ€‰>â€‰0.01) (2128 CpG sites), (2) SNP-enriched sites (4100 sites), (3) out of a CpG context (not on a CG) (3149 sites), or (4) located on sex chromosomes (11,129 sites). A total of 465,071 CpG sites were analyzed initially. Signal was then normalized, first by scaling to the internal controls using the methylumi R package, then by applying the method of subset-quantile within array normalization (SWAN) implemented in the minfi R package.	Illumina 450K	167
EGAD00010001594	None	Illumina 450K	24

Publications	Citations
Exploring rare and low-frequency variants in the Saguenay-Lac-Saint-Jean population identified genes associated with asthma and allergy traits. Morin A, Madore AM, Kwan T, Ban M, Partanen J, Rönnblom L, Syvänen AC, Sawcer S, Stunnenberg H, Lathrop M, Pastinen T, Laprise C. Eur J Hum Genet 27: 2019 90-101	6