Polydactyly
Overview
Polydactyly is a congenital physical anomaly in humans, dogs, and cats involving supernumerary fingers or toes. This condition is characterized by the presence of more than the usual number of digits on the hands or feet. Polydactyly is a topic of interest in the fields of genetics, pediatrics, and orthopedics.
Etiology
Polydactyly can occur as an isolated finding in a person who is otherwise normal or it can be associated with a genetic syndrome or condition. The condition can be caused by mutations in various genes and can be inherited in an autosomal dominant manner. The most common gene associated with polydactyly is the Sonic Hedgehog gene (SHH).
Classification
Polydactyly is classified into three types: preaxial (extra digits on the thumb or big toe side), postaxial (extra digits on the little finger or little toe side), and central (extra digits in the middle). Each type can further be classified into subtypes based on the presence of bone in the extra digit.
Diagnosis
Diagnosis of polydactyly can often be made prenatally through an ultrasound examination. After birth, the condition can be diagnosed through physical examination and X-ray imaging.
Treatment
Treatment for polydactyly depends on the severity of the condition and the presence of bone in the extra digit. In some cases, the extra digit may be tied off shortly after birth; in other cases, surgical removal may be necessary.
Epidemiology
Polydactyly is one of the most common congenital limb malformations. It occurs in approximately 1 in every 1,000 births, with a higher prevalence in people of African descent.
Research
Research into polydactyly is ongoing, with scientists studying the genetic causes of the condition and developing new treatment options.
