Prevalence and Clinical Features of Inflammatory Bowel Diseases Associated With Monogenic Variants, Identified by Whole-Exome Sequencing in 1000 Children at a Single Center. Gastroenterology 2020 Jun;158(8):2208-2220
Date
02/23/2020Pubmed ID
32084423Pubmed Central ID
PMC7283012DOI
10.1053/j.gastro.2020.02.023Scopus ID
2-s2.0-85085745909 (requires institutional sign-in at Scopus site) 74 CitationsAbstract
BACKGROUND & AIMS: A proportion of infants and young children with inflammatory bowel diseases (IBDs) have subtypes associated with a single gene variant (monogenic IBD). We aimed to determine the prevalence of monogenic disease in a cohort of pediatric patients with IBD.
METHODS: We performed whole-exome sequencing analyses of blood samples from an unselected cohort of 1005 children with IBD, aged 0-18 years (median age at diagnosis, 11.96 years) at a single center in Canada and their family members (2305 samples total). Variants believed to cause IBD were validated using Sanger sequencing. Biopsies from patients were analyzed by immunofluorescence and histochemical analyses.
RESULTS: We identified 40 rare variants associated with 21 monogenic genes among 31 of the 1005 children with IBD (including 5 variants in XIAP, 3 in DOCK8, and 2 each in FOXP3, GUCY2C, and LRBA). These variants occurred in 7.8% of children younger than 6 years and 2.3% of children aged 6-18 years. Of the 17 patients with monogenic Crohn's disease, 35% had abdominal pain, 24% had nonbloody loose stool, 18% had vomiting, 18% had weight loss, and 5% had intermittent bloody loose stool. The 14 patients with monogenic ulcerative colitis or IBD-unclassified received their diagnosis at a younger age, and their most predominant feature was bloody loose stool (78%). Features associated with monogenic IBD, compared to cases of IBD not associated with a single variant, were age of onset younger than 2 years (odds ratio [OR], 6.30; P = .020), family history of autoimmune disease (OR, 5.12; P = .002), extra-intestinal manifestations (OR, 15.36; P < .0001), and surgery (OR, 3.42; P = .042). Seventeen patients had variants in genes that could be corrected with allogeneic hematopoietic stem cell transplantation.
CONCLUSIONS: In whole-exome sequencing analyses of more than 1000 children with IBD at a single center, we found that 3% had rare variants in genes previously associated with pediatric IBD. These were associated with different IBD phenotypes, and 1% of the patients had variants that could be potentially corrected with allogeneic hematopoietic stem cell transplantation. Monogenic IBD is rare, but should be considered in analysis of all patients with pediatric onset of IBD.
Author List
Crowley E, Warner N, Pan J, Khalouei S, Elkadri A, Fiedler K, Foong J, Turinsky AL, Bronte-Tinkew D, Zhang S, Hu J, Tian D, Li D, Horowitz J, Siddiqui I, Upton J, Roifman CM, Church PC, Wall DA, Ramani AK, Kotlarz D, Klein C, Uhlig H, Snapper SB, Gonzaga-Jauregui C, Paterson AD, McGovern DPB, Brudno M, Walters TD, Griffiths AM, Muise AMAuthor
Abdul Aziz Elkadri MD Associate Professor in the Pediatrics department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AdolescentAge Factors
Biological Products
Child
Child, Preschool
Colitis, Ulcerative
Crohn Disease
Female
Genetic Predisposition to Disease
Genetic Variation
Hematopoietic Stem Cell Transplantation
Humans
Infant
Infant, Newborn
Male
Ontario
Phenotype
Prevalence
Risk Assessment
Risk Factors
Transplantation, Homologous
Treatment Outcome
