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 moder ately 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. Th e 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 susceptibil ity 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-depen dent penetrances for males with the AA genotype by the ages of 60 and 80 ye ars were 41.6% and 95.2%, respectively, whereas, for females, they were 26. 4% and 60.5%, respectively. Incorporating environmental risk factors-such a s cigarette smoking, pipe smoking, alcohol drinking, eating hot food, and e ating pickled vegetables-into the models did not provide significant improv ement of the fit of the models to these data. The results suggest a major l ocus underlying susceptibility to esophageal cancer with sex-specific penet rance.