This activity guides the analysis of a published scientific figure from a study that used SNP genotyping to identify genes involved in autism.

In this study, scientists collected data from a family with an autistic son to locate genes that may contribute to autism. The scientists used a genotyping technique called homozygosity mapping to find mutations associated with recessive genetic disorders. The figure shows a pedigree for the family (left) and SNP genotyping results for each family member on chromosome 3 (right). Red and blue vertical stripes indicate homozygous SNPs, yellow stripes represent heterozygous SNPs, and white gaps represent genetic deletions. The “Educator Materials” document includes a captioned figure, background information, graph interpretation, and discussion questions. The “Student Handout” includes a captioned figure and background information.