ONE AFFECTED OFFSPRING Diagnosis and age at onset of disease (years) Birth order Rank of affected sib/ total number of sibs Family number Father Son Daughter 74 HL 63 CLL 60     1/1 86 HL 49     CLL 58 2/3 30 FL 55 CLL 43     2/3 25 DLBCL 67 HL 36     2/3 11 DLBCL 74 CLL 46     2/3 46 DLBCL 54 CLL 43     3/3 68 LPL 65 MM 42     2/4 5-29 MZL 66 CLL 42     2/2 6 CLL 66     DLBCL 64 3/3 Age at onset, father-offspring: P= 0.02 (Wilcoxon test, pair difference, two- sided) Birth order effect         6A (95%CI): 114 (74-130) ,P > 0.05 (Haldane Smith test)   Mother Son Daughter   69 DLBCL 70     DLBCL 49 1/1 27 BL 68 CLL 47     1/3 67 LPL 75 HL 26     2/2 75 NOS 70 CLL 61     ½ 107 CLL 82 FL 46     2/2 16 CLL 78 LPL 76     2/3 Age at onset, mother-offspring P = 0.032 54 (40-74) P>0.05 TWO AFFECTED OFFSPRING   Father Son Daughter   114 HL 55     CLL ,CLL 60,60 1/2, 2/2 38 FL 75 CLL, MM 61,60     2/3, 3/3 1 CLL 75 T, CLL 57, 70     2/5, 4/5 80 MM 91 DLBCL,CLL 35, 52     1/2, 2/2   Mother           97 NOS 88     CLL, CLL 69, 67 3/4, 4/4 Age at onset, parent-offspring P = 0.014 144 (99-153) P> 0.05 BOTH PARENT’S LINES AFFECTED 82 Father DLBCL 80 yr - Daughter CLL 61 yr Mother’s sister HL   115 Mother BL 76 yr – Son CLL 63 yr Father’s father CLL

Abbreviations: 6A of the Haldane Smith test for birth order effect is the sum of birth orders from affected persons, compared with the theoretical value, expressed as the 95 per cent confidence interval. Other abbreviations, see footnote to Table 1.

Table 2: Familial malignant lymphoma. Parent-offspring combinations.