Figure 2.

Origins of de novo mutations in ASD. (a) Parent-of-origin of germline and somatic variants. Number of germline de novo SNVs and de novo indels derived from the father was significantly higher than that from the mother. On the other hand, there are significantly more clustered (within 20 kb) germline de novo mutations originating from the mother than from the father, while somatic mutations can be found in similar proportion from both parents. (b) Number of de novo SNVs found on the paternal allele increases with the age of father, but there is no correlation between the number of de novo SNVs found on the maternal allele and the age of the mother. (c) Distance between de novo mutations is shorter than expected for a subset of de novo mutations both between and within individuals. (d) Mutation rate is significantly higher than the background within 100 kb flanking the de novo CNVs.