Deladoëy Johnny, Bélanger Nicole, Van Vliet Guy
Endocrinology Service and Research Center, Sainte-Justine Hospital, University of Montréal, H3T 1C5 Québec, Canada.
J Clin Endocrinol Metab. 2007 Aug;92(8):3158-61. doi: 10.1210/jc.2007-0527. Epub 2007 May 15.
Research on the etiology of congenital hypothyroidism from thyroid dysgenesis (CHTD) (comprising mostly ectopy and agenesis) over the past decade has focused on genetic mechanisms. However, the possibility that environmental factors might be involved has been raised by studies showing a seasonal variability of the incidence of CHTD.
The objective of this study was to assess the variability in incidence of CHTD in the province of Québec, Canada.
DESIGN, SETTING, PATIENTS, AND MAIN OUTCOME MEASURE: The Québec provincial newborn screening database was analyzed from January 1990 to December 2005. Only cases of permanent congenital hypothyroidism with thyroid ectopy or agenesis on scintigraphy were analyzed.
During the study period, 1,303,341 children were screened, and 424 cases of permanent congenital hypothyroidism were diagnosed, giving an overall incidence of 1:3074. Of these, 306 had CHTD (overall incidence 1:4259) from either ectopy (n = 231) or agenesis (n = 75). Over the 16 yr of the study, this incidence remained stable (P = 0.57), and no significant variability in monthly incidence was found (P = 0.87).
The incidence of CHTD did not vary over the observation period, and its monthly variation was random. Therefore, environmental factors do not appear to play a significant role in the etiology of CHTD.
过去十年，关于甲状腺发育异常所致先天性甲状腺功能减退症（CHTD，主要包括异位和发育不全）病因的研究聚焦于遗传机制。然而，一些研究显示CHTD发病率存在季节性变化，这引发了环境因素可能参与其中的可能性。
本研究旨在评估加拿大魁北克省CHTD发病率的变化情况。
设计、地点、患者及主要观察指标：分析了1990年1月至2005年12月魁北克省新生儿筛查数据库。仅分析了甲状腺闪烁显像显示为永久性先天性甲状腺功能减退症且伴有甲状腺异位或发育不全的病例。
研究期间，共筛查了1,303,341名儿童，确诊424例永久性先天性甲状腺功能减退症，总体发病率为1:3074。其中，306例患有CHTD（总体发病率1:4259），病因包括异位（n = 231）或发育不全（n = 75）。在研究的16年中，该发病率保持稳定（P = 0.57），且未发现月发病率有显著变化（P = 0.87）。
在观察期内，CHTD发病率无变化，且其月度变化是随机的。因此，环境因素似乎在CHTD病因中不起重要作用。
