Table 1.

Demographic and genetic characteristics of the study population

Colorectal cancer, n = 95No colorectal cancer, n = 90Total, N = 185 (%)
Gender
    Male553489 (48.1)
    Female405696 (51.9)
Age at onset* (y)
    Mean (SD)41.7 (11.0)42.7 (11.8)42.2 (11.4)
    Median404241
    Range23-7518-7718-77
MMR gene mutated
    MLH1464086 (46.5)
    MSH2495099 (53.5)
MMR gene mutation type
    Missense211940 (21.5)
    Deletion/insertion/nonsense/splice7471145 (74.4)
MTHFR
    A1298CAA4951100 (54.0)
AC363066 (35.7)
CC10717 (9.2)
Unable to genotype2 (1.1)
    (Any C) AC+CC463783 (44.9)
    C677TCC433275 (40.5)
CT424486 (46.5)
TT101424 (13.0)
    (Any T) CT+TT5258110 (59.5)
  • * Age is mean age at colorectal cancer onset for individuals with colorectal cancer and mean age at censoring for unaffected MMR gene mutation carriers (subjects were censored at age at last blood draw or at last contact, or at diagnosis of colorectal adenoma or cancer other than colorectal cancer).

  • These missense mutations were confirmed to be pathogenic mutations by a Clinical Laboratory Improvement Act–certified laboratory or from the International Collaborative Group-HNPCC InSiGHT database (48) or from the published literature (49, 50).