Table 2.

Genotypic New Mutations in the CMMT Database^[Note]

Repeat Length in
Father	Offspring	Age Difference(years)	Offspring Affected?	Probability of Mutationa
34	36	31	No	.21
35	36	36	No	.52
31	44	34	Yes	1.7×10-7
33	44	27	Yes	2.1×10-6
35	45	27	Yes	1.2×10-4
30	49	NA	Yes	NA
34	43	NA	Yes	NA
27	38	NA	Yes	NA

Note.— Because of the specific interest that the research groups (e.g., Goldberg et al. 1993, 1995; Chong et al. 1997) have in these patients, new mutations may be slightly overrepresented in the CMMT database. To be conservative, we have included only examples in which DNA is available from both parents. In two additional cases, DNA from only one parent is available; in four other cases, the new mutation has been inferred on the basis of the repeat length in sibs.

^aUnder the mitotic model.