Autophagy genes variants and paediatric Crohn's disease phenotype: a single-centre experience

Abstract

Background and aims: Little evidence demonstrating the correlation between several single nucleotide polymorphisms and a specific phenotype of Crohn's disease has been reported in children. We investigated the relationship between autophagy genes variants and clinical features in our children with Crohn's disease.

Methods: Genotyping for ATG16L1, NOD2/CARD15, and IRGM1 was performed in 80 consecutive patients with Crohn's disease (median age: 11 years; range: 0.7-17.9 years). Crohn's disease location and behaviour were classified using the Paris classification. Additional data were collected from clinical records on patients' demographics, age at symptom onset and diagnosis, extraintestinal manifestations, therapy, clinical relapses, and need of surgical intervention.

Results: Patients homozygous for the risk allele ATG16L1 (T300A) showed a trend towards switching to a stricturing phenotype during the course of disease compared to children either homozygous for the wild-type allele or heterozygous for the ATG16L1 single nucleotide polymorphism (p=0.01). Homozygosity for the ATG16L1 risk allele was associated with a major recurrence of clinical relapses and earlier introduction of immunosuppressants (p=0.006 and p=0.04, respectively). Heterozygosity for the NOD2 rs2066847 allele was associated with major ileal involvement (p=0.01).

Conclusion: In patients carrying the T300A variant, Crohn's disease follows a more aggressive clinical course.

Keywords: Autophagy; Crohn's disease; Genome wide association studies; Inflammatory bowel diseases.