Table 1.

Summary of families studied by diagnosis and ethnicity

	CD-only families	UC-only families	Mixed families	All families
Number of families	99	13	62	174
Affecteds genotyped (n)
Non-Ashenazim Caucasians	156	33	83	272  (62%)
Ashkenazim	100	6	56	162  (37%)
Other	2	0	3	5  (1%)
Total	258	39	142	439
Affected relative pairs (n)
Sibling pair	97	18	36	151
Uncle-niece	29	2	25	56
Grandparent-grandchild	7	1	9	17
More distant	42	5	26	73
Total	175	26	96	297