在常规筛选视网膜母细胞瘤(Rb)病人时,发现红细胞溶解产物中酯酶D(ESD)活性为正常对照者的50%,此病人在13q14区有微缺失。在13q14区全部或部分缺失的病例中,基因缺失易患Rb。在25%～40%的非缺失病例中,Rb遗传为高度外显性常染色体显性孟德尔性状。ESD基因位于13q14区,并且显示与遗传型Rb紧密连锁。携带杂合子13q14区的个体显示 In a routine screening of patients with retinoblastoma (Rb), the activity of esterase D (ESD) in erythrocyte lysates was found to be 50% of those in normal controls. This patient had microdeletions in the 13q14 region. In cases where all or part of the 13q14 region is missing, gene deletion is predisposed to Rb. In 25% to 40% of non-missing cases, Rb is inherited as a highly penetrant autosomal dominant Mendelian trait. The ESD gene is located in the 13q14 region and is shown to be closely linked to the hereditary Rb. Individual display of heterozygous 13q14 region