哈德福厦郡为英国一个郡,位于大伦敦之北部,人口940,630。尽管最近工业及人口增加很快,但仍保留有不少农村,可分四个卫生区。过去对严重智力障碍的调查多偏重于流行病学,很少涉及病因。瑞典农村有过流行病学及病因学的调查报告,最近城市也有报告,但农村材料与城市的不易进行比较。本报告目的是对1965年1月初到1967年12月末出生并生长在哈德福厦郡的儿童所有患严重智力障碍的病人作一病因学调查。 Hadford County is a county in England, located in the north of Greater London, population 940,630. In spite of the recent rapid increase in industry and population, many rural areas are still retained and can be divided into four health districts. In the past, surveys of severe mental retardation were more prevalent in epidemiology and seldom involved etiology. Surveys of epidemiology and etiology have been reported in rural Sweden, and recent reports from cities are available, but comparisons between rural materials and cities are not easy. The purpose of this report is to conduct an etiological survey of all patients with severe mental retardation who were born between January 1965 and January 1967 and grown in Haadfordshire County.