Segregation analysis of esophageal cancer in a moderately high-incidence area of northern China

In order to explore the mode of inheritance of esophageal cancer in a moderately high-incidence area of northern China, we conducted a pedigree survey on 225 patients affected by esophageal cancer in Yangquan, Shanxi Province. Segregation analysis was performed using the REGTL program of S.A.G.E. The results showed that Mendelian autosomal recessive inheritance of a major gene that influences susceptibility to esophageal cancer provided the best fit to the data. In the best-fitting recessive model, the frequency of the disease allele was.2039. There was a significant sex effect on susceptibility to the disease. The maximum cumulative probability of esophageal cancer among males with the AA genotype was 100%, but, among females, it was 63.5%. The mean age at onset for both men and women was 62 years. The age-dependent penetrances for males with the AA genotype by the ages of 60 and 80 years were 41.6% and 95.2%, respectively, whereas, for females, they were 26.4% and 60.5%, respectively. Incorporating environmental risk factors-such as cigarette smoking, pipe smoking, alcohol drinking, eating hot food, and eating pickled vegetables-into the models did not provide significant improvement of the fit of the models to these data. The results suggest a major locus underlying susceptibility to esophageal cancer with sex-specific penetrance.