The following pedigree depicts a rare maternally inherited disorder present in two different families called Leber hereditary optic neuropathy. Provide an explanation for the difference in the pedigrees shown. Select one: a. The allele is more common in the second pedigree b. There is inbreeding in the second pedigree c. The disease allele is incompletely dominant d. The disease allele is incompletely penetrant e. The disease allele shows variable expressivity Solution d-The diseases allele is incompletely penetrant-primary mutation is the major risk factor in accordance with the other etiological factors being necessary..

1. The following pedigree depicts a rare maternally inherited disorder present in two different
families called Leber hereditary optic neuropathy. Provide an explanation for the difference in
the pedigrees shown. Select one: a. The allele is more common in the second pedigree b. There
is inbreeding in the second pedigree c. The disease allele is incompletely dominant d. The
disease allele is incompletely penetrant e. The disease allele shows variable expressivity
Solution
d-The diseases allele is incompletely penetrant-primary mutation is the major risk factor in
accordance with the other etiological factors being necessary.