Journal Article

Feasibility of salivary DNA collection in a population-based case-control study: a pilot study of pediatric Crohn's disease

Kappelman, Michael, Laugesen, Kristina, Lange, Aksel, Frøslev, Trine, Sandler, Robert, Christensen, Tina, Basta, Patricia, Randell, Rachel, Erichsen, Rune, Byrjalsen, Anna

2018

Overview

Epidemiologic studies combining exposure and outcome data with the collection of biosamples are needed to study gene-environment interactions that might contribute to the etiology of complex diseases such as pediatric Crohn's disease (CD). Nationwide registries, including those in Denmark and other Scandinavian countries, provide efficient and reliable sources of data for epidemiological studies evaluating the environmental determinants of disease. We performed a pilot study to test the feasibility of collecting salivary DNA to augment registry data in established cases of pediatric CD and randomly selected, population-based controls. Cases of CD born after 1995 and residing in the central region of Denmark were identified through the Danish National Patient Registry and confirmed by using standard diagnostic criteria. Age- and gender-matched controls were selected at random through the civil registration system. Cases and controls were contacted by mail and telephone and invited to submit a saliva sample. DNA was extracted and genotyped for six CD-associated single-nucleotide polymorphisms (SNPs). A total of 53 cases of pediatric CD were invited, and 40 contributed a saliva sample (75% response rate). A total of 126 controls were invited, and 54 contributed a saliva sample (44% response rate). As expected, demographic characteristics did not differ between cases and controls. DNA was successfully isolated from 93 of 94 samples. Genotyping was performed with only 2% undetermined genotypes. For five of six SNPs known to be associated with CD, risk allele frequencies were higher in cases than controls. This pilot study strongly supports the feasibility of augmenting traditional epidemiological data from Danish population-based registries with the de novo collection of genetic information from population-based cases and controls. This will facilitate rigorous studies of gene-environment interactions in complex chronic conditions such as CD.

• Publisher: Dove Medical Press Limited,Taylor & Francis Ltd,Dove Medical Press
• Subject: Cancer / children / Chronic illnesses / Clinical medicine / Crohn's disease / Deoxyribonucleic acid / DNA / Epidemiology / Etiology (Medicine) / Feasibility studies / Gastroenterology / Gene expression / Genes / genetic / Genetic aspects / Genetic polymorphisms / Genetic testing / Genomes / Genotypes / Inflammatory bowel disease / Medical research / Original Research / Parents & parenting / Patients / Pediatric diseases / Pediatric research / Pediatrics / Personal identification numbers / Polymorphism / Population / Population-based studies / Single nucleotide polymorphisms / SNP