BACKGROUND _ AIMS: In 1988, we reported the first twin study in @entity29 . The aim of the current study was to follow up these twins regarding new cases of @entity29 and @entity30 characteristics using the Vienna classification. METHODS: The official Swedish population register and the cause of @entity204 register were used to search for the twins. All living @entity1 were interviewed. RESULTS: Three monozygotic twins earlier classified as healthy had been diagnosed with @entity29 ( @entity31 , n = 2; @entity30 , n = 1). Retrospectively, all 3 were symptomatic at the original survey. This changed the pair concordance in monozygotic twins from 6.3% to 18.8% in @entity31 and from 44.4% to 50.0% in @entity30 . A high degree of concordance regarding age at diagnosis, disease location at diagnosis and during the course, and disease behavior was found in concordant monozygotic twin pairs with @entity30 . Seven of 9 pairs were identical in 3 or more of these disease characteristics compared with an expected number of 1.5 (P = 0.000076). CONCLUSIONS: This study confirms that the genetic influence is stronger in @entity30 than in @entity31 . A remarkable phenotype similarity within concordant pairs with @entity30 was found using the Vienna classification.

XXXX in a Swedish twin cohort: a long-term follow-up of concordance and clinical characteristics.

@entity1 :: ('9606', 'Species') :: ['patients'] @entity31 :: ('MESH:D003093', 'Disease') :: ['ulcerative colitis'] @entity29 :: ('MESH:D015212', 'Disease') :: ['inflammatory bowel disease'] @entity204 :: ('MESH:D003643', 'Disease') :: ['death'] @entity30 :: ('MESH:D003424', 'Disease') :: ["Crohn's disease"]
@entity29 :: (MESH:D015212,Disease) :: ['Inflammatory bowel disease']
