2. Mendelian pedigree patterns
further complications
imprinting

3. Mendelian pedigree patterns
further complications
imprinting
Paternal imprinting:
normal function of gene A is associated with
epigenetic inactivation of the paternal allele
Maternal imprinting:
normal function of gene A is associated with
epigenetic inactivation of the maternal allele

4. Mendelian pedigree patterns
further complications
imprinting
Disease phenotype caused by
imprinting of the nonimprinted allele
loss of imprint
Example
Phenotype arises only through male transmission

5. Mendelian pedigree patterns
further complications
P- M+
P- M+
P- M*+
P- M+
erase imprint
paternal imprint
erase imprint
paternal imprint P- M+
P*+ M+ P- M+