It can be surprising and emotional for parents to see a newborn with six fingers on one or both hands. The first thought is often worry, wondering if this extra finger means something is seriously wrong or if the child will face challenges growing up. In many cases, however, having six fingers is simply a variation called polydactyly, a condition that develops during pregnancy while the baby’s hands are forming. It is far more common than most people realise and is often harmless, with many children growing up with completely normal hand function. Understanding what causes polydactyly, how it affects development and when treatment might be recommended helps reduce fear and encourages informed decisions.A peer-reviewed study published in Frontiers in Genetics explains that polydactyly occurs due to small changes in genetic signalling during early limb development. Researchers identified several genes involved in non-syndromic polydactyly, including GLI3, ZNF141 and IQCE, which help control how the hand forms in the womb. When these signals shift, an extra digit can develop.
Understanding polydactyly and why extra fingers appear
Polydactyly is a congenital condition, meaning it is present at birth. The word comes from Greek: poly, meaning many and dactylos, meaning fingers. Instead of the usual five digits, one or more extra fingers develop on the hand. It can occur on one hand only or on both, and it sometimes appears along with extra toes.Polydactyly is one of the most common limb differences seen in newborns. It can happen in families due to inheritance, but it can also occur randomly with no previous family history. In many babies, the condition is isolated and not linked to any other medical issues.There are three main types:• Postaxial polydactyly: Extra finger near the little finger, the most common form• Preaxial polydactyly: Extra thumb, less common but often more functionally important• Central polydactyly: Extra digit between the middle fingers, rare and usually more complexThe extra digit may be a small soft tissue nub or a fully formed finger with bones, joints and nerves.
Why do some babies have 6 fingers and others do not
During pregnancy, the hands start as small paddle-shaped structures. As development progresses, they separate into individual fingers. This process depends on precise genetic signalling pathways. If those signals are altered even slightly at the crucial time, more than five fingers can form.Polydactyly can be inherited through families, particularly postaxial polydactyly which commonly follows an autosomal dominant pattern. This means that if one parent has the condition, the child has a higher chance of inheriting it. However, it can also appear spontaneously through a new genetic variation.In some cases, polydactyly can be part of a broader syndrome where other organs or systems are affected. This is less common, but in those cases, doctors may recommend additional tests to ensure the baby is healthy overall.
Is having 6 fingers dangerous or harmful
In most cases, having six fingers is not dangerous at all. Many children with fully developed extra digits have normal strength, sensation and movement. For some, the extra finger even functions independently, offering improved grip or dexterity.In 2019, researchers studied two adults with six fully formed fingers and found they could move the extra digits independently, allowing them to perform complex tasks more easily and without strain. This study, published in Nature, showed that the brain naturally adapts to control additional fingers, suggesting a potential functional advantage.The primary considerations are usually cosmetic preference, social confidence and whether the digit interferes with movement.
When is treatment needed, and how is polydactyly managed
The decision to remove an extra finger depends on how it is formed and whether it affects function. Doctors first assess the structure through physical examination or occasionally imaging.• Soft tissue extra digits (attached only by skin) can sometimes be removed easily in infancy.• Fully formed digits with bones and joints require careful surgical planning and usually occur later, often after twelve months of age, for better results.If the condition is part of a genetic syndrome, additional medical care and testing may be recommended, including genetic counselling for families, which can help understand future risks.After surgery, physiotherapy may help with strength and coordination, though many children adapt naturally.
Living with 6 fingers and embracing difference
For many families, the initial shock gives way to understanding and acceptance. Children with polydactyly typically grow up to live completely normal lives, especially when the condition is isolated. Some families choose to keep the extra finger rather than remove it and have reported positive experiences.Parents should feel reassured that polydactyly is manageable and usually harmless. The important step is getting a proper evaluation after birth to determine whether treatment is needed.Being born with six fingers is simply one of many natural variations in human development. Understanding polydactyly removes stigma and replaces fear with knowledge and support. Whether managed surgically or embraced as it is, what matters most is ensuring healthy function and confidence for the child.Disclaimer: This article is for general informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider regarding any medical condition or lifestyle change.Also read| Diabetes that appears overnight? Experts say it could be your pancreas crying for help
