Hexadactyly refers to having an additional finger or toe, making it six in total, a condition that is quite common. The term "hexadactyly" literally translates to "six digits." Medically, it doesn't differentiate between fingers or toes, even though the Greek word "dactylos" specifically means finger. This extra digit can appear in one of three places: on either side of the hand or foot or somewhere in between. For instance, on the hand, the extra finger might be found beyond the little finger (known as ulnar hexadactyly), beyond the thumb, or situated between two regular fingers (intercalary hexadactyly). Ulnar hexadactyly, or postaxial hexadactyly, is the most common form. This is followed by radial, or preaxial, hexadactyly. Intercalary hexadactyly is the rarest.Hexadactyly itself is generally harmless and can be easily corrected, especially when it occurs in an otherwise healthy baby. A simple case, such as a small sixth digit or a skin tag, can be treated by tying it off. However, hexadactyly may also be part of a series of congenital abnormalities, making treatment more complex and the prognosis less certain.Ultrasound scans can sometimes detect hexadactyly. In one real-life example, an ultrasound identified a small extra digit on both hands. A detailed scan confirmed this extra digit on the ulnar side of each hand was merely a soft skin tag, with no other physical anomalies visible. A higher-resolution ultrasound later showed a similar tag between the fourth and fifth fingers, again with no other abnormalities.The list of potential disorders linked to hexadactyly is extensive, but many options were ruled out due to the lack of additional anomalies. If the extra digit had been intercalary, the list would narrow significantly, pointing to conditions like Pallister-Hall syndrome or Greig syndrome, which typically have other symptoms. The final diagnosis in this case remains pending, illustrating the diagnostic challenges when hexadactyly is identified before birth.Hexadactyly is the most prevalent form of polydactyly, a condition that covers all instances of extra digits, regardless of their number in any specific case.
