{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,13]],"date-time":"2025-12-13T23:01:35Z","timestamp":1765666895179,"version":"3.45.0"},"reference-count":24,"publisher":"BMJ","issue":"6","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Gut"],"accepted":{"date-parts":[[1999,1,13]]},"published-print":{"date-parts":[[1999,6,1]]},"abstract":"<jats:sec>\n                    <jats:title>BACKGROUND<\/jats:title>\n                    <jats:p>Genetic anticipation has been proposed to explain observed age differences at diagnosis of Crohn\u2019s disease in affected parents and offspring.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>AIMS<\/jats:title>\n                    <jats:p>To compare affected parent-child pairs with Crohn\u2019s disease and ulcerative colitis with a control group of non-familial patients with inflammatory bowel disease (IBD) in order to quantify whether ascertainment bias could account for this effect.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec sec-type=\"methods\">\n                    <jats:title>METHODS<\/jats:title>\n                    <jats:p>137 affected parent-child pairs from 96 families and 214 patients with sporadic IBD were studied. Age at onset of symptoms and diagnosis were ascertained by interview and disease confirmed from clinical records.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>RESULTS<\/jats:title>\n                    <jats:p>Of the 137 affected parent-child pairs, 50 had Crohn\u2019s disease only, 51 had ulcerative colitis only, and in 36, one had Crohn\u2019s disease and the other ulcerative colitis. The median age of parents at diagnosis was 17.5 years older, 16 years older, and 18 years older in the Crohn\u2019s disease, ulcerative colitis, and mixed disease families respectively (p&lt;0.001 in each case). These observed age differences were compatible with those predicted from the regression lines of years of birth against age at diagnosis for the non-familial IBD patients. No evidence was found for an effect of parental sex on age at diagnosis or disease extent in offspring.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>CONCLUSIONS<\/jats:title>\n                    <jats:p>There was no evidence of genetic anticipation or genomic imprinting of age at diagnosis in this sample of IBD families. Ascertainment bias is responsible for the age differences at diagnosis between affected parents and children.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/gut.44.6.808","type":"journal-article","created":{"date-parts":[[2010,6,30]],"date-time":"2010-06-30T12:46:12Z","timestamp":1277901972000},"page":"808-811","source":"Crossref","is-referenced-by-count":41,"title":["Why children with inflammatory bowel disease are diagnosed at a younger age than their affected parent"],"prefix":"10.1136","volume":"44","author":[{"given":"J C W","family":"Lee","sequence":"first","affiliation":[{"name":"aSt Mark\u2019s Hospital, Northwick Park, Harrow, Middlesex, UK, \n\nbDepartment of Medicine, King\u2019s College School of Medicine and Dentistry, London, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"S","family":"Bridger","sequence":"additional","affiliation":[{"name":"aSt Mark\u2019s Hospital, Northwick Park, Harrow, Middlesex, UK, \n\nbDepartment of Medicine, King\u2019s College School of Medicine and Dentistry, London, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"C","family":"McGregor","sequence":"additional","affiliation":[{"name":"aSt Mark\u2019s Hospital, Northwick Park, Harrow, Middlesex, UK, \n\nbDepartment of Medicine, King\u2019s College School of Medicine and Dentistry, London, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"A J S","family":"Macpherson","sequence":"additional","affiliation":[{"name":"aSt Mark\u2019s Hospital, Northwick Park, Harrow, Middlesex, UK, \n\nbDepartment of Medicine, King\u2019s College School of Medicine and Dentistry, London, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"J E Lennard","family":"Jones","sequence":"additional","affiliation":[{"name":"aSt Mark\u2019s Hospital, Northwick Park, Harrow, Middlesex, UK, \n\nbDepartment of Medicine, King\u2019s College School of Medicine and Dentistry, London, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[1999,6,1]]},"reference":[{"key":"2025112111203692000_44.6.808.1","doi-asserted-by":"publisher","DOI":"10.1136\/gut.35.5.696"},{"key":"2025112111203692000_44.6.808.2","doi-asserted-by":"publisher","DOI":"10.1136\/gut.29.7.990"},{"key":"2025112111203692000_44.6.808.3","doi-asserted-by":"publisher","DOI":"10.1136\/bmj.312.7023.95"},{"key":"2025112111203692000_44.6.808.4","doi-asserted-by":"publisher","DOI":"10.1038\/379821a0"},{"key":"2025112111203692000_44.6.808.5","doi-asserted-by":"publisher","DOI":"10.1093\/hmg\/5.10.1679"},{"key":"2025112111203692000_44.6.808.6","doi-asserted-by":"crossref","first-page":"1588","DOI":"10.1016\/S0140-6736(05)66204-6","article-title":"Susceptibility loci in inflammatory bowel disease.","volume":"348","author":"Parkes","year":"1996","journal-title":"Lancet"},{"key":"2025112111203692000_44.6.808.7","doi-asserted-by":"publisher","DOI":"10.1038\/ng1096-199"},{"key":"2025112111203692000_44.6.808.8","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(96)90870-3"},{"key":"2025112111203692000_44.6.808.9","doi-asserted-by":"publisher","DOI":"10.1136\/gut.42.2.170"},{"key":"2025112111203692000_44.6.808.10","doi-asserted-by":"crossref","first-page":"A3112","DOI":"10.1016\/S0016-5085(98)84066-3","article-title":"Date of birth in familial Crohn\u2019s disease suggests environmental factors [abstract].","volume":"114","author":"Hugot","year":"1998","journal-title":"Gastroenterology"},{"key":"2025112111203692000_44.6.808.11","doi-asserted-by":"crossref","first-page":"A3118","DOI":"10.1016\/S0016-5085(98)84033-X","article-title":"Anticipation in inflammatory bowel disease: a phenomenon caused by a cumulation of confounders [abstract].","volume":"114","author":"Hampe","year":"1998","journal-title":"Gastroenterology"},{"key":"2025112111203692000_44.6.808.12","first-page":"A3128","article-title":"Age difference at diagnosis between parents and children with inflammatory bowel disease: genetic anticipation or a cohort effect [abstract].","volume":"114","author":"Lee","year":"1998","journal-title":"Gastroenterology"},{"key":"2025112111203692000_44.6.808.13","doi-asserted-by":"crossref","first-page":"A3129","DOI":"10.1016\/S0016-5085(98)84029-8","article-title":"Genetic anticipation in fifteen three generation families with inflammatory bowel disease [abstract].","volume":"114","author":"Gurubhagavatula","year":"1998","journal-title":"Gastroenterology"},{"key":"2025112111203692000_44.6.808.14","doi-asserted-by":"crossref","first-page":"A3131","DOI":"10.1016\/S0016-5085(98)84027-4","article-title":"Anticipation in Crohn\u2019s disease may be influenced by the ethnicity of the transmitting parent [abstract].","volume":"114","author":"Gulwani-Akolkar","year":"1998","journal-title":"Gastroenterology"},{"key":"2025112111203692000_44.6.808.15","doi-asserted-by":"publisher","DOI":"10.1016\/S0016-5085(98)70381-6"},{"key":"2025112111203692000_44.6.808.16","first-page":"A950","article-title":"Age of onset and \u201cgenetic anticipation\u201d in inflammatory bowel disease [abstract].","volume":"112","author":"Chutkan","year":"1997","journal-title":"Gastroenterology"},{"key":"2025112111203692000_44.6.808.17","doi-asserted-by":"publisher","DOI":"10.1146\/annurev.ge.29.120195.003415"},{"key":"2025112111203692000_44.6.808.18","doi-asserted-by":"crossref","first-page":"683","DOI":"10.1016\/S0733-8619(18)30071-9","article-title":"Genetic anticipation: expanding tandem repeats.","volume":"12","author":"Carpenter","year":"1994","journal-title":"Neurol Clin"},{"key":"2025112111203692000_44.6.808.19","doi-asserted-by":"publisher","DOI":"10.1136\/gut.38.5.738"},{"key":"2025112111203692000_44.6.808.20","first-page":"973","article-title":"Anticipation: an old idea in new genes.","volume":"59","author":"McInnis","year":"1996","journal-title":"Am J Hum Genet"},{"key":"2025112111203692000_44.6.808.21","doi-asserted-by":"publisher","DOI":"10.1053\/gast.1996.v111.pm8780559"},{"key":"2025112111203692000_44.6.808.22","doi-asserted-by":"publisher","DOI":"10.1053\/gast.1996.v111.pm8780562"},{"key":"2025112111203692000_44.6.808.23","first-page":"A985","article-title":"Is there anticipation in familial Crohn\u2019s disease [abstract]?","volume":"112","author":"Griffiths","year":"1997","journal-title":"Gastroenterology"},{"key":"2025112111203692000_44.6.808.24","doi-asserted-by":"publisher","DOI":"10.1056\/NEJM199610173351609"}],"container-title":["Gut"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/gut.44.6.808","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,11,21]],"date-time":"2025-11-21T19:20:45Z","timestamp":1763752845000},"score":1,"resource":{"primary":{"URL":"https:\/\/gut.bmj.com\/lookup\/doi\/10.1136\/gut.44.6.808"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1999,6,1]]},"references-count":24,"journal-issue":{"issue":"6","published-online":{"date-parts":[[1999,6,1]]},"published-print":{"date-parts":[[1999,6,1]]}},"alternative-id":["10.1136\/gut.44.6.808"],"URL":"https:\/\/doi.org\/10.1136\/gut.44.6.808","relation":{},"ISSN":["0017-5749","1468-3288"],"issn-type":[{"type":"print","value":"0017-5749"},{"type":"electronic","value":"1468-3288"}],"subject":[],"published":{"date-parts":[[1999,6,1]]}}}