Re: Why do I have a dimple in my cheek?

Cheek dimples are examples of a phenotype (or appearance) due to the expression of a dominant gene, so you probably inherited your dimple or dimples from your parents. Plus, cheek dimples may look different on different people, so while one person may have obvious dimples another may have dimples that are hard to see. I don't know what the physiology of dimples is, but here is some info on the genetics. It doesn’t have to be both parents though. Since it is a dominant gene, the pattern would look like this:

Mother: cheek dimple; Father: cheek dimple; Child: cheek dimple

Mother: no cheek dimple Father: cheek dimple Child: cheek dimple

Mother: cheek dimple Father: no cheek dimple Child: cheek dimple

Mother: no cheek dimple Father: no cheek dimple Child: no cheek dimple

This is called a simple dominant-recessive inheritance. There are two genes for cheek dimples, and a child receives one from each. So if we use the letter C for a dominant cheek dimple gene (cheek dimple appearance) and c for a recessive gene (no cheek dimple phenotype or appearance) then the options for the genotype and phenotype would look like the below. Each persons’ genotype is and phenotype is shown in parentheses.

Mother: CC (appearance of cheek dimple); Father: CC (appearance of cheek dimple); Child: CC (appearance of cheek dimple) only possible outcome

Mother: CC (appearance of cheek dimple); Father: cc (no appearance of cheek dimple); Child: Cc (appearance of cheek dimple) only possible outcome

Mother: cc (no appearance of cheek dimple); Father: CC (appearance of cheek dimple); Child: Cc (appearance of cheek dimple) only possible outcome

Mother: cc (no appearance of cheek dimple); Father: Cc (appearance of cheek dimple); Child: Cc (appearance of cheek dimple) or cc (no appearance of cheek dimple), equally likely outcomes

Mother: Cc (appearance of cheek dimple); Father: cc (no appearance of cheek dimple); Child: Cc (appearance of cheek dimple) or cc (no appearance of cheek dimple), equally likely outcomes

Mother: cc (no appearance of cheek dimple); Father: Cc (appearance of cheek dimple); Child: Cc (appearance of cheek dimple) or cc (no appearance of cheek dimple), equally likely outcomes

Mother: cc (no appearance of cheek dimple); Father: cc (appearance of cheek dimple);Child: cc (no appearance of cheek dimple

For more information, see Marieb, Human Anatomy & Physiology, 4th edition, 1998, p.1113, and Pessa JE et al. The Anatomy of the Cheek Dimple. Clinical Anatomy. 1998.