Sammanfattning

Background: Dissecting the role copy number variants (CNVs) play in disease pathogenesis is directly reliant on accurate methods for quantification. The Shar-Pei dog breed is predisposed to a complex autoinflammatory disease with numerous clinical manifestations. One such sign, recurrent fever, was previously shown to be significantly associated with a novel, but unstable CNV (CNV_16.1). Droplet digital PCR (ddPCR) offers a new mechanism for CNV detection via absolute quantification with the promise of added precision and reliability. The aim of this study was to evaluate ddPCR in relation to quantitative PCR (qPCR) and to assess the suitability of the favoured method as a genetic test for Shar-Pei Autoinflammatory Disease (SPAID).Results: One hundred and ninety-six individuals were assayed using both PCR methods at two CNV positions (CNV_14.3 and CNV_16.1). The digital method revealed a striking result. The CNVs did not follow a continuum of alleles as previously reported, rather the alleles were stable and pedigree analysis showed they adhered to Mendelian segregation. Subsequent analysis of ddPCR case/control data confirmed that both CNVs remained significantly associated with the subphenotype of fever, but also to the encompassing SPAID complex (p < 0.001). In addition, harbouring CNV_16.1 allele five (CNV_16.1 vertical bar 5) resulted in a four-fold increase in the odds for SPAID (p < 0.001). The inclusion of a genetic marker for CNV_16.1 in a genome-wide association test revealed that this variant explained 9.7 % of genetic variance and 25.8 % of the additive genetic heritability of this autoinflammatory disease.Conclusions: This data shows the utility of the ddPCR method to resolve cryptic copy number inheritance patterns and so open avenues of genetic testing. In its current form, the ddPCR test presented here could be used in canine breeding to reduce the number of homozygote CNV_16.1 broken vertical bar 5 individuals and thereby to reduce the prevalence of disease in this breed.

Nyckelord

Copy number variation; Autoinflammation; Droplet digital PCR; Quantitative PCR

Publicerad i

BMC Genomics
2016, Volym: 17, artikelnummer: 299
Utgivare: BIOMED CENTRAL LTD

SLU författare

• Hedhammar, Åke

  • Institutionen för kliniska vetenskaper, Sveriges lantbruksuniversitet
    

UKÄ forskningsämne

Klinisk vetenskap


Publikationens identifierare

DOI: https://doi.org/10.1186/s12864-016-2619-0

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/83091