Polydactyly is a genetic disease characterized by an abnormal number of fingers or toes. It is a common congenital abnormality in the hand, and can present as an isolated disorder, or be associated with other conditions. Polydactyly is caused by genetic mutations during development in the mother’s womb. The deformity can be inherited as a standalone condition or associated with other genetic diseases. Polydactyly can be diagnosed as early as the first three months of pregnancy when your child is still in the womb by using an ultrasound or embryo-fetoscopy.