Lorenzen T, Pociot F, Hougaard P, Nerup J
Steno Diabetes Center, Gentofte, Denmark.
Diabetologia. 1994 Mar;37(3):321-7. doi: 10.1007/BF00398061.
Due to a short observation period previous studies may have underestimated prevalence and recurrence risk of IDDM in relatives of IDDM patients. To obtain a more exact life-time risk estimate we identified 310 probands, representative of Danish IDDM patients, characterized by current age more than 50 years, age at onset 40 years or less and diabetes duration of more than 30 years. Family data were obtained from 291 probands. Mean "observation" times (age) (+/- SD) for siblings (n = 553) and offspring (n = 359) were 59.4 +/- 16.1 years and 33.8 +/- 8.8 years, respectively. Of the probands 73 (25.1%) had at least one first-degree relative with IDDM. Seventeen percent had at least one affected sibling. An increase from 10.4% to 22.4% of having first-degree relatives with IDDM among probands with age at onset below 20 years was observed during the period from proband at age 21 years up to 1 September 1992. Among affected siblings 48% of the second cases were affected more than 10 years after the first affected sibling. Using the life-table method cumulative recurrence risks from time of birth were calculated for siblings up to age 30 years of 6.4% and up to age 60 years of 9.6%. For offspring the risk up to age 34 years was 6.3%. In addition, we present a life-table method evaluating the cumulative recurrence risk from time of onset in the proband, as this is the most relevant when giving genetic counselling. In conclusion, the long-term risks of IDDM in siblings and offspring are high compared to that shown in previous reports.
由于观察期较短，以往的研究可能低估了IDDM患者亲属中IDDM的患病率和复发风险。为了获得更准确的终生风险估计，我们确定了310名先证者，他们代表丹麦的IDDM患者，其特征为当前年龄超过50岁、发病年龄40岁或更小且糖尿病病程超过30年。从291名先证者那里获得了家族数据。兄弟姐妹（n = 553）和后代（n = 359）的平均“观察”时间（年龄）（±标准差）分别为59.4±16.1岁和33.8±8.8岁。在这些先证者中，73名（25.1%）至少有一名患IDDM的一级亲属。17%的人至少有一名患病的兄弟姐妹。在从先证者21岁到1992年9月1日期间，观察到发病年龄低于20岁的先证者中，有IDDM一级亲属的比例从10.4%增加到了22.4%。在患病的兄弟姐妹中，48%的第二例患者在第一例患病兄弟姐妹之后10年以上患病。使用生命表法，计算出兄弟姐妹从出生到30岁的累积复发风险为6.4%，到60岁为9.6%。后代到34岁的风险为6.3%。此外，我们还提出了一种生命表法，用于评估从先证者发病时起计算的累积复发风险，因为在进行遗传咨询时这是最相关的。总之，与以往报告相比，兄弟姐妹和后代患IDDM的长期风险较高。
