Example of a pedigree showing imprinting

Imprinting. An example of a pedigree demonstrating genomic imprinting is presented. At this locus, the paternal allele is normally repressed and the maternal allele is normally expressed. Approximately 50% of offspring of affected women are themselves affected, whereas no offspring of affected men are affected. However, the grandchildren of affected males will be affected if the mutation is passed through a carrier (unaffected) daughter, but not if passed through a carrier son.