Friday, January 30, 2015
Inherited Disorders and Birth Defects
Birth defect - Phocomelia
Hi there, I was born missing 3 fingers on my right hand. I have my thumb & 1st finger but the rest are stumps. I was also born with a very long looking pupil in my right eye (don`t know if these are connected). I was just wondering, can you tell me or do you know of a cause for this? My mother said she never took any drugs whilst pregnant and my siblings are all fine. There is no family history at all. Looking forward to hearing from you. I am from Ireland.
The birth defect you describe of your right hand seems to be what is called a limb reduction defect.
The term phocomelia usually describes a defect where both the lower and upper part of the arm is missing and the hand appears to be attached at the shoulder - this is the defect that was noted in infants of mothers that took thalidomide during early pregnancy.
The arms and legs begin to develop starting in the 4th to 5th week of pregnancy after conception. By the end of the 7th to 8th week of pregnancy, the limbs including the hands, feet, fingers and toes are well formed.
Such birth defects are usually isolated, that is, it is the only birth defect present and may be caused by exposures to environmental agents (such as what happened with thalidomide). However, we usually never know if there was some type of exposure that caused the birth defect. While there have been many agents found to be capable of producing limb reduction defects in experimental animals, very few have been related to humans.
Limb reduction defects may also be from an indirect cause, for example with loss of blood supply to part of the limb during development. There is research that shows that smoking or having increased blood pressure (hypertension) during pregnancy can lead to these types of birth defects.
There are many genetic syndromes that have limb reduction defects as part of them, but they usually have many other body systems involved as well. I cannot say if the shape of your pupil is related to your hand abnormality, however, there are a few genetic syndromes that have both problems of the eye as well as of limbs. Again, most of these have many other additional problems present.
If you are concerned about whether or not your children could have similar problems, you may want to talk to a medical geneticist to examine your hand and eye to see if there is a chance these things are related.
You can look at the American Society of Human Genetics membership list by putting in a city and the country to locate a geneticist in Ireland. The website is below.
Anne Matthews, RN, PhD
Associate Professor of Genetics
School of Medicine
Case Western Reserve University