Having six fingers, a condition known as polydactyly, is not generally considered rare, though some specific forms of it are less common.
Understanding Polydactyly
Polydactyly refers to the presence of extra fingers or toes. It is a congenital condition, meaning it's present at birth. While it may seem unusual, it occurs more frequently than one might expect.
Incidence of Polydactyly
According to research, the overall incidence of polydactyly is around 0.2% in the population. This figure indicates that it's not a rare condition in the general sense.
- Overall Polydactyly: Approximately 2 out of every 1000 births will have some form of polydactyly.
Types of Polydactyly
Polydactyly can manifest in various forms. It's often categorized based on the location of the extra digit:
- Preaxial Polydactyly: The extra digit is located on the thumb side of the hand or the big toe side of the foot.
- Fully Formed Preaxial Polydactyly: This specific type, where the extra digit is well-developed, is considered a rarer subset.
- Postaxial Polydactyly: The extra digit is located on the pinky finger or little toe side. This form is more common.
- Central Polydactyly: The extra digit appears in the middle of the hand or foot, which is less common.
Are All Forms of Polydactyly Equally Common?
No, while polydactyly overall is not rare, certain types are less common than others:
| Type of Polydactyly | Commonality |
|---|---|
| Overall Polydactyly | Not rare (approx. 0.2%) |
| Fully Formed Preaxial Polydactyly | Rarer |
| Postaxial Polydactyly | More common than preaxial |
| Central Polydactyly | Less common |
Conclusion
While having extra fingers or toes (polydactyly) is not rare overall, with an incidence of about 0.2% in the population, specific forms like fully formed preaxial polydactyly are less common. Therefore, seeing a person with six fingers is not necessarily an extremely rare event, but the presentation may differ.
