Expert: Dana Krempels, Ph.D. - 7/21/2009

Question
I have attached ear lobes and my husband has free earlobes, my son also has free ear lobes! My question is... Are my sons ears suppose to look exactly like his dad's ears, he has the free ear lobes but they don't look exactly like my husbands ears! Why is that? Or are they suppose to look the exact same as one ours?? Thank you for you time it is greatly appriecated!

Answer
Dear Danielle,

There seems to be something wrong with the AllExperts site.  I answered this question a couple of days ago, but it seems to have stayed in my inbox.  I'll re-post the answer in case you didn't get it the first time.

Attached ear lobes are considered to be recessive to pendulous/free ear lobes, though the degree of "freeness" can vary among individuals.  A person carries two genes for every trait, one inherited from mom, and one from dad.  A recessive version of the gene (we'll call the ear lobe recessive version "e") is masked by the dominant version ("E").  So to have attached earlobes, you must have the genotype ee.  Your husband could have either EE or Ee.  No way to know for sure unless you have a child with attached earlobes, in which case he would be Ee (the only way a child of the two of you could have two copies of e is to get one from each parent).

Your son's genotype is certainly Ee for the attached/pendulous trait, but his ears may not look exactly like either yours or your husband's because the overall shape of the ear is controlled by many different genes, and may be affected by environmental factors (in utero), as well.  The interaction of the many genes involved in forming an ear will cause each individual's ear to be pretty much unique.

Hope that helps.

Dana