Understanding Polydactyly and Syndactyly Through David Tennant's Experience
This article explores the anatomical variations of polydactyly and syndactyly, as exemplified by David Tennant's experience with having 11 toes. It describes their prevalence, causes, and related syndromes.
A common anatomical variation is being born with more than ten fingers or more than ten toes. Former Doctor Who actor David Tennant this week confirmed he has 11 toes, which indicates he was born with polydactyly.
The term polydactyly is derived from the Greek “poly” (meaning many) and “dactyly” (referring to fingers or toes). This variation occurs when an extra finger or toe grows from the limb bud during embryonic development. Based on research, approximately one in 700 to 1,000 people are born with polydactyly.
The most common forms of polydactyly include an extra digit on the side of the little finger or little toe. If the extra digit lacks bone or has poor muscle connections, it often gets surgically removed shortly after birth.
Less frequently, some individuals are born with double thumb tips or an additional thumb. An orthopaedic surgeon may need to remove the extra bone to enhance the thumb's functionality. The rarest type of polydactyly involves the fourth finger (ring finger) or the second toe (next to the big toe).
There are ten known syndromes associated with polydactyly, including Bardet-Biedl and McKusick-Kaufman. These syndromes may affect the head and upper limbs, and typically, a paediatrician diagnoses them early in life. If one has polydactyly without any linked syndromes, it usually indicates the inheritance of a dominant mutated gene from a parent.
Another common anatomical variant is syndactyly, characterised by fused or "webbed" fingers or toes. This condition occurs similarly in the womb when the cells in between emerging digits fail to die and disappear. About one in 2,000 to 3,000 people have syndactyly, making it less common than polydactyly.
There are nine different types of syndactyly and eleven syndromes associated with it, with some overlap between syndactyly and polydactyly. Most types of syndactyly require just one mutated gene from a parent to manifest.
In conclusion, anatomical variations such as polydactyly and syndactyly are more common than one might think. These variations reveal the remarkable diversity within human anatomy.
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