Unaffected Individuals (n=302) CMM Cases (n=136) P N % N % Age at blood draw           <35 74 24.5 31 22.8    35-45 89 29.5 33 24.3   46-50 35 11.6 19 14.0   50+ 104 34.4 53 39.0 0.616 Gender             Female 172 57.0 73 53.7     Male 130 43.1 63 46.3 0.537 CDKN2A             Non-Carrier 262 86.8 77 56.6     Carrier 40 13.3 59 43.4 <0.0001 Dysplastic nevi             Unaffected 143 47.4 2 1.5     Affected 119 39.4 103 97.7 <0.0001 Moles             0-24 93 30.8 5 3.6     25-99 105 34.8 27 19.9     100+ 81 28.8 81 59.6 <0.0001 Freckles           Non/few 92 30.4 17 12.5   Moderate 51 16.9 19 14.0   Many 75 24.8 49 36.0 <0.0001 Solar injury             None/mild 184 60.9 52 38.2     Moderate 58 19.2 38 27.9     Severe 38 12.6 23 16.9 0.0002 Tanning ability             Tan/Little burn 147 48.7 44 14.6     Burn/Little tan 118 39.1 68 22.5 0.0116 Skin type             Dark/medium 87 28.8 17 12.5     Pale/fair 187 61.9 96 70.6 0.0013 Eye color             Black/brown 69 22.8 19 14.0     Hazel 62 20.5 25 18.4     Green/gray 24 7.9 17 12.5     Blue 120 39.7 52 38.2 0.1626 Hair Color           Black/brown 124 41.1 35 25.7   Blonde brown/light brown 74 24.5 27 19.9   Blonde 47 15.6 12 8.8   Red 30 9.9 13 9.6 0.1598

Table 2: Distribution of age, gender, CDKN2A, pigmentation phenotype, and sun exposure variables in 53 melanoma-prone families by CMM status. P-values were obtained by comparing CMM cases to unaffected individuals using logistic regression with a generalized estimating equation and adjusting for familial correlation in the variance