A single gene influences several apparently unrelated traits, as in Marfan syndrome.
One gene product used in many tissues causes several effects. Marfan syndrome (fibrillin-1 mutation) affects the skeleton, eyes and aorta; sickle cell allele affects blood, spleen and malaria resistance.
Pleiotropy complicates selection because a gene beneficial for one trait may harm another.
A single gene influences several apparently unrelated traits, as in Marfan syndrome.
Pleiotropy is one of the 54 topics in Genetics. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Codominance, Quantitative Trait Loci, Homozygous and Heterozygous.
Phenylketonuria affects intelligence and pigmentation through one enzyme deficiency.
Work through the Beginner topics in Genetics first, such as Heredity, Gene, Allele, then return to Pleiotropy. Intermediate topics assume the Beginner vocabulary.
The closest topics to Pleiotropy are Codominance, Quantitative Trait Loci, Homozygous and Heterozygous, Heredity. Comparing them side by side is a good way to see how the ideas connect.
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Pleiotropy. To practise the whole of Genetics, use the Genetics quiz.
Pleiotropy: A single gene influences several apparently unrelated traits, as in Marfan syndrome. Codominance: Both alleles are fully expressed in the heterozygote, as in the AB blood type. Read both side by side and note what each one explains.
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Codominance and explain the difference aloud. Finally, take the Genetics quiz and come back to this page for any question you miss.
Both alleles are fully expressed in the heterozygote, as in the AB blood type.
🧬 GeneticsRegions of the genome statistically associated with variation in continuous traits.
🧬 GeneticsHomozygous means two identical alleles for a gene; heterozygous means two different alleles.
🧬 GeneticsThe passing of traits from parents to offspring through genetic material.
🧬 Genetics