[Phenotyping and genotyping in patients with inflammatory bowel disease in a reference center in Colombia]. / Fenotipificación y genotipificación en pacientes con enfermedad inflamatoria intestinal en un centro de referencia de Colombia.

INTRODUCTION: Attempts have been made to identify the genetic factors related to susceptibility to inflammatory bowel disease (IBD), and the current conclusions are in favor of a complex pathology model, without a clear hereditary pattern. OBJECTIVE: To perform phenotypic and genotypic characterization of patients with IBD in Colombian population and to describe its possible association with predisposition. MATERIALS AND METHODS: case series, 16 patients with IBD according to clinical and pathological criteria, onset of gastrointestinal symptoms after 18 years of age. All had pre-test genetic counseling and family trees of at least three generations were made. Also, genotyping, using a multi-gene panel that included genes related to IBD and some autoimmune disorders. Finally, a genomic analysis of variants was performed. RESULTS: 9 women and 7 men, with mean age of diagnosis of IBD of 35 years, and gastrointestinal symptoms appearance of 32 years. 11/16 (68.75%) required biological therapy. 10/16 (62.5%) were refractory to standard therapy. 3/16 (18.75%) had positive family history of IBD. 100% cases presented at least one single nucleotide polymorphism related to IBD risk in more than one gene. The genes most related to ulcerative colitis (UC) were CD48, CD6, and TYK2 for UC, and CD6 and ITGAM for Crohn's disease. The most frequent gene was CD6. It was found presence of up to 5 genes in 3/16 (18.75%), 4 in 3/16 (18.75%), and three in 5/16 (31.25%). CONCLUSION: In IBD there is the presence of genetic variants with associated predisposition, but without confirmed pathogenicity, and whose sum seems to contribute to its pathophysiology.

Fenotipificación y genotipificación en pacientes con enfermedad inflamatoria intestinal en un centro de referencia de Colombia / Phenotyping and genotyping in patients with inflammatory bowel disease in a reference center in Colombia

RESUMEN Introducción: Se ha tratado de identificar los factores genéticos relacionados con susceptibilidad para enfermedad inflamatoria intestinal (EII), y los hallazgos actuales se inclinan por un modelo de patología complejo, sin un patrón hereditario claro. Objetivo: Realizar caracterización fenotípica y genotípica de pacientes con EII en población colombiana y describir su posible asociación con predisposición. Materiales y métodos: Serie de casos, 16 pacientes con EII por criterios clínicos y anatomopatológicos, inicio de síntomas gastrointestinales después de los 18 años. Todos tuvieron asesoramiento genético pre-test y se realizaron árboles genealógicos de mínimo tres generaciones. También, genotipificación, por medio de un panel de genes múltiples que incluía genes relacionados con EII y algunos trastornos autoinmunitarios. Finalmente, se realizó análisis genómico de variantes. Resultados: 9 mujeres y 7 hombres, con edad media de diagnóstico de EII 35 años, y 32 años para aparición de síntomas gastrointestinales. 11/16(68,75%) requirieron terapia biológica. 10/16 (62,5%) presentaron refractariedad a terapia estándar. 3/16 (18,75%) tenían antecedentes familiares positivos de EII. 100% casos presentaron al menos un single nucleotide polymorphism relacionado con riesgo de EII en más de un gen. Los genes más relacionados con colitis ulcerosa (CU), fueron CD48, CD6, y TYK2 para CU, y CD6 e ITGAM para la enfermedad de Crohn. El gen más frecuente fue CD6. Se observó en 3/16 (18,75%) presencia de hasta 5 genes, 4 en 3/16 (18,75%), y tres en 5/16 (31,25%). Conclusión: En EII hay presencia de variantes genéticas con predisposición asociada, pero sin patogenicidad confirmada, y cuya sumatoria parece contribuir en su fisiopatología.

ABSTRACT Introduction: Attempts have been made to identify the genetic factors related to susceptibility to inflammatory bowel disease (IBD), and the current conclusions are in favor of a complex pathology model, without a clear hereditary pattern. Objective: To perform phenotypic and genotypic characterization of patients with IBD in Colombian population and to describe its possible association with predisposition. Materials and methods: case series, 16 patients with IBD according to clinical and pathological criteria, onset of gastrointestinal symptoms after 18 years of age. All had pre-test genetic counseling and family trees of at least three generations were made. Also, genotyping, using a multigene panel that included genes related to IBD and some autoimmune disorders. Finally, a genomic analysis of variants was performed. Results: 9 women and 7 men, with mean age of diagnosis of IBD of 35 years, and gastrointestinal symptoms appearance of 32 years. 11/16 (68.75%) required biological therapy. 10/16 (62.5%) were refractory to standard therapy. 3/16 (18.75%) had positive family history of IBD. 100% cases presented at least one single nucleotide polymorphism related to IBD risk in more than one gene. The genes most related to ulcerative colitis (UC) were CD48, CD6, and TYK2 for UC, and CD6 and ITGAM for Crohn's disease. The most frequent gene was CD6. It was found presence of up to 5 genes in 3/16 (18.75%), 4 in 3/16 (18.75%), and three in 5/16 (31.25%). Conclusion: In IBD there is the presence of genetic variants with associated predisposition, but without confirmed pathogenicity, and whose sum seems to contribute to its pathophysiology.