ECE2006 Poster Presentations Thyroid (174 abstracts)
1University of Birmingham, Birmingham, United Kingdom; 2Sheffield University, Sheffield, United Kingdom; 3Royal Bournemouth Hospital, Bournemouth, United Kingdom; 4University of Wales College of Medicine, Cardiff, United Kingdom; 5Newcastle University, Newcastle, United Kingdom; 6Peninsula Medical School, Universities of Exeter and Plymouth, Exeter, United Kingdom.
The association of autoimmune thyroid diseases (AITD) with other autoimmune disorders is well documented. Familial prevalence of thyroid dysfunction and other autoimmune diseases was examined in our cohort of 2296 with Graves disease (GD) (1920 females, 376 males) and 361 with Hashimotos thyroiditis (HT) (313 females, 48 males), probands being recruited using standard diagnostic criteria. FH was ascertained using a standardised structured questionnaire.
A high proportion of GD and HT probands had parents with thyroid dysfunction (GD females, n=363, 18.9%, GD males, n=71, 18.9%; HT females, n=95, 30.4%; HT males, n=13, 27.1. The prevalence of siblings with thyroid dysfunction was similar in GD and HT (GD females, n=241, 12.5%; GD males, n=42, 11.2%; HT females, n=41, 13.1%; HT males, n=6, 12.5%). Risk to the siblings (lambda (s)) of probands with AITD was derived using data from the Whickham survey (GD lambda(s)=8.50; HT lambda(s)=8.98).
Autoimmune diseases were more prevalent in AITD index cases than reported general population prevalence including type 1 diabetes (GD: n=25 cases, 3.2 fold higher prevalence; HT: n=3, 2.4 fold higher), pernicious anaemia (GD: n=31, 10.4 fold higher; HT: n=12, 25.6 fold higher) and rheumatoid arthritis (GD: n=67, 5.3 fold higher; HT n=12, 6.0 fold higher). Increased risk of Addisons disease was observed, especially in HT probands (HT: n=10; 308 fold higher; GD: n=6, 29.0 fold higher). Age of diagnosis of AITD was decreased if family members had type 1 diabetes (GD females: 40.0y [3049], n=252 vs 43.0 [3254], n=716; P=0.009), type 2 diabetes (GD females: 39.0 [3049], n=569 vs 43.0 [3254], n=716 or rheumatoid arthritis (GD females: 39.0 [3050], n=507 vs 43.0 [3254], n=716; P<0.001) when compared to probands without FH of autoimmune diseases. Striking family associations are consistent with a common genetic aetiology, across a wide range of autoimmune disorders.