The diagram on the left is a pedigree of a mother (AU-3104), father (AU-3103), daughter (AU-3101) and son with autism (AU-3101). Female symbols are circles and males are squares. Unaffected individuals are open symbols and the autistic son is a shaded symbol. The double line connecting the two parents indicates that they are related. Each horizontal bar represents a map of single nucleotide polymorphisms (SNPs) along one arm of chromosome 3 of the family members. Red and blue vertical stripes indicate homozygous SNPs for either one of two alleles, yellow stripes represent heterozygous SNPs, and white gaps represent genetic deletions. The horizontal black line demarcates a region of with a pattern of homozygosity not found in the autistic boy’s parents or sister.
The accompanying downloadable Educator Materials PDF, which includes background information, graph interpretation and discussion questions, and the Student Handout, which includes the image and background information, have been remediated to comply with Section 508 of the National Rehabilitation Act for accessibility and can be used with screen readers.
Figure 1A from:
Morrow, Eric M., et al. Identifying Autism Loci and Genes by Tracing Recent Shared Ancestry. 2008. Science 321(5886): 218-223.