Family history, atopy demonstrate genetic risk factors for pediatric IBD
MedWire News: Pediatric inflammatory bowel disease (IBD) is predicted by a family history of the disease and childhood atopy, Scottish research suggests.
The study of family and environmental factors was presented at the Gastro 2009 meeting in London, UK, by Johan Van Limbergen (University of Edinburgh, UK).
Acknowledging the rising incidence of pediatric IBD in Scotland, the team examined potential risk factors in 139 children diagnosed before 17 years of age with Crohn’s disease (n=90), ulcerative colitis (UC, n=36), or IBD unclassified type (IBDU, n=130). The patients were matched to a control by age, gender, and location as a surrogate for socioeconomic status.
Parents of the patients were interviewed in person regarding whether their child was breastfed, and their child’s surgical, medical, and immunisation history, and family history of IBD. Controls were interviewed by postal questionnaire.
On initial analysis, IBD development was predicted by parental smoking during pregnancy, the postnatal period, and at the time of child’s diagnosis, compared with no parental smoking (odds ratios [ORs]=1.78, 1.87, and 1.78, respectively).
In addition, pediatric IBD was associated with family history for IBD (OR=5.14), and a patient history of asthma, eczema, and food allergy (ORs=2.23, 2.76, and 2.84, respectively), but not hayfever.
The incidence of pediatric IBD did not significantly differ between children who had and had not been breastfed.
However, in multifactorial analysis, only family history of IBD (OR=4.07) and history of eczema (OR=3.09) or asthma (OR=2.59) were significant predictors for development of pediatric IBD, pointing to a strong genetic risk, Van Limbergen said.
This finding is confirmed by research published this week advance online by the journal Nature Genetics and co-authored by Van Limbergen, revealing a link between five novel chromosomal regions and risk for early-onset IBD.
The genome-wide study included 3426 patients who were diagnosed with IBD before the age of 19 years and 11,963 controls in Europe and North America.
Analysis revealed that loci 16p11 (close to the gene for cytokine interleukin-27), 22q12, 10q22, and 19q13.11 were associated with early-onset IBD susceptibility. The researchers also found links between early-onset IBD risk and 23 of 32 loci previously linked to adult-onset IBD, and at eight of 17 loci linked to adult-onset UC.
“Our study adds insight into the pathogenic mechanisms mediating early-onset IBD and its close relationship with adult-onset disease,” say Hakon Hakonarson (Children’s Hospital of Philadelphia, Pennsylvania, USA) and co-authors.
They conclude: “Our discovery of five new IBD susceptibility loci through analysis of genetically enriched early-onset disease cohort underscores the validity of this approach in the study of complex disease.”
MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2009
By Lynda Williams