A family history of rheumatoid arthritis, type 1 diabetes mellitus, or celiac disease is associated with a higher risk of developing autism spectrum disorders in children, a recent study found.

A group of Danish and U.S. researchers collected medical data on all children born in Denmark to Danish mothers between 1993 and 2004 and matched these children with their parents' and siblings' hospital records. Any diagnoses of autoimmune diseases identified before the children were diagnosed with an autism spectrum disorder were analyzed for possible correlations with the children's risk for such a disorder.

Among 689,196 children, 3,325 had a diagnosis of an autism spectrum disorder. Rheumatoid arthritis in mothers was associated with a 70 percent increase in the risk of autism spectrum disorders in children （risk ratio 1.70, 95 percent confidence interval [CI] 1.07 to 2.54）. Mothers'celiac disease was associated with nearly three times the risk of autism spectrum disorders compared with children of mothers who did not have celiac disease （risk ratio 2.97, 95 percent CI 1.27 to 5.75）. Family history of type 1 diabetes, with parents and siblings included, was associated with a statistically significant increase in the risk of the childhood autism diagnosis （risk ratio 1.78, 1.16 to 2.61）, but not the risk of the overall class of autism spectrum disorders.

These risk associations remained statistically significant even after the authors limited the analyses to children who were born neither pre-term nor underweight and who had no obvious distress at birth （Apgar score above 6）. This suggests that the observations cannot be entirely explained by detrimental effects on the fetus due to the mother's autoimmune disease. Combined with other research evidence, the authors speculated that certain autoimmune diseases may share a common genetic root with autism.

Other autoimmune diseases, such as multiple sclerosis, psoriasis, and Crohn's disease, in parents and siblings were not significantly associated with autism spectrum disorders in the study children. Furthermore, a family history of thyrotoxicosis was the only autoimmune disease studied that was associated with a lower risk of autism spectrum disorder.

The study was published in the August Pediatrics and was funded by grants from the U.S. National Institute of Mental Health and the Aarhus University Research Foundation in Denmark.

Because of the nationalized health care and central medical registries in Denmark, decades of complete medical data of all Danish citizens in the databases provide a valuable resource for epidemiologic research. In a study published in the February 21, 2004, British Medical Journal, Eaton and colleagues found that a parental history of celiac disease was associated with increased risk of schizophrenia in offspring, also using theDanish national health care registries.

Celiac disease is an often-undiagnosed autoimmune disease triggered by gluten in wheat-containing foods. Patients usually suffer from gastrointestinal symptoms and nutritional deficiencies because the intestinal linings are attacked and damaged by immune responses to even a minute amount of gluten intake. According to a recent Mayo Clinic study, the prevalence of celiac disease has increased fourfold from the 1950s. The study was published in the July Gastroenterology. The reason for the trend remains unknown.

最近的一项研究发现，具有家族病史，如类风湿型关节炎、1型糖尿病或乳糜泻的儿童患孤独症的的可能更高。

一组来自丹麦及美国的研究人员收集了所有1993至2004年间，出生在丹麦、其生母也为丹麦人的儿童的医学数据资料，并与其父母及兄弟姐妹的病史进行比对。在比对中，任何在儿童被诊断患有孤独症之前对于其自身免疫系统疾病的确诊，都经过分析以建立儿童免疫系统疾病与孤独症之间可能的关联性。

在689,196名儿童中，3,325名被诊断患有孤独症。当儿童的母亲患有类风湿性关节炎，她们的孩子患孤独症的几率增高了百分之七十。当儿童的母亲患有乳糜泻，她们的孩子患孤独症的几率三倍于那些未患此病母亲的孩子。具有家族1型糖尿病史（包括父母及兄弟姐妹的病史）的儿童，患有孤独症的几率最高。

即便研究者将分析研究局限于那些既没有早产也在分娩时没有明显的痛苦迹象（既Apgar值高于6）的儿童，然而这种患病的关联性表现在数据上依然很显着。这说明了之前的调查不能将所有对新生儿的不良影响都归咎与其生母所患的自身免疫系统疾病。结合其他研究结果，研究人员们猜想这种免疫系统疾病也许与孤独症具有相同的基因来源。

然而，儿童的父母、兄弟姐妹是否患有其他的自身免疫系统疾病，比如多发性硬化、牛皮癣以及克隆氏病，这与儿童患孤独症并没有很显着的关联性。另外，研究发现，具有家族甲亢病史是目前为止唯一一种与较低的孤独症患病率相关联的自身免疫系统疾病。

这项研究发表在八月的《小儿科》期刊上，并且此研究受到了凯子美国国家心理健康机构以及丹麦奥胡思大学的资助。

得益于丹麦来自国家的健康保障以及统一的医疗信息记录措施，由全部丹麦公民的信息资料库中几十年完整的医疗记录档案为这项流行病学研究提供了非常有价值的资源。在一项于2004年2月21日发表于《英国医疗期刊》的调查中，伊顿以及同事发现父母具有乳糜泻病史，与其孩子患精神症的几率的增高有关。调查也参考了来自丹麦国家健康保障机构的记录数据。

乳糜泻是一种多发的由含小麦的食物中麸质诱发的自身免疫系统疾病。病患往往表现为肠胃不适症状以及营养不良，这是由于因微量麸质引起的自身免疫系统反应作用攻击并损害了肠道。根据最近的一项来自Mayo医疗机构的研究，乳糜泻愈发广泛的流行，从50年代起至今，发病率已经翻了四倍。这项调查发表在四月的《肠胃病学》期刊上。造成这种流行趋势的原因至今还不清楚。