Monday, October 20, 2014
Inherited Disorders and Birth Defects
I have syndactyly of one foot which I believe may be `sporadic` - I don`t think anyone else in my family has it. Does this mean that I don`t have a gene that codes for syndactyly and therefor cannot pass it on to my children? Or can the gene still be passed on as an autosomal dominant inherited trait? It is something that really bothers me. Thank you.
As you know, syndactyly is webbing that occurs between fingers and toes. The most common type involves only the skin (no bones involved) and is between the 2nd and 3rd toes or between the middle finger and ring finger. It is very common - about 1 in 2,000 people. As you mention, it can be sporadic, that is, no one else in the family has the same thing and we do not know what factors were involved in why it happened during development. In this case, we would not expect it to happen again.
We also know that it can be inherited in what is called autosomal dominant inheritance. When there is only 1 person in the family that is affected, however, we do not know if it is sporadic or if it has happened for the first time in the family. In your case, you could be the first person in your family to have a gene that causes syndactyly. There is still so much that is not known about specific genes that can cause syndactyly.
If you a gene mutation (or change) in a specific gene that causes syndactyly, then you would have a 50-50 chance of passing that gene on to any child you may have. There is no specific gene test which can tell us if you have a mutation, so at this time, we could not tell you if any of your children will also have syndactyly.
Finally, syndactyly can also be seen in many genetic disorders, but these children usually have multiple problems, not just syndactyly. If it is something that really bothers you, you should ask your doctor to refer you to a geneticist or genetic counselor to talk specifically about the inheritance of syndactyly. You can locate a genetics center near you at the National Society of Genetic Counselors’ Resource website.
Anne Matthews, RN, PhD
Associate Professor of Genetics
School of Medicine
Case Western Reserve University