1. What is polydactyly? Polydactyly, also known as heavy fingers (toes), is a hand (foot) deformity in which the hand (foot) grows more than the normal number of fingers (toes). Polydactyly is the most common congenital deformity of the hand in the Chinese population, with the most common growth occurring next to the thumb. It has been documented in biblical literature as early as 3,000 years ago, and there are approximately 9,000 to 10,000 new cases each year. There are three main types of polydactyly: radial – duplication of the thumb (split thumb); central – duplication of the index, middle or ring finger; and ulnar – duplication of the little finger. Also heavy fingers include ulnar-sided duplication limb deformity, or mirror hand, a very rare deformity. 2. What are the dangers? Does it affect other organs? Most children’s deformities do not have a significant impact on hand (foot) function, except for more complex polydactyly that will affect the development and function of the child’s hand (foot). A small number of syndromes, such as Holt-Oram syndrome (malformation of the skeletal and cardiovascular systems), are part of the spectrum of polydactyly. 3. What are the causative factors of polydactyly? Most of them are disseminated, which suggests that the disease is related to environmental factors. It has been found that the administration of acytosine during pregnancy in mice can cause radial polydactyly in the offspring. Autosomal dominant inheritance and sporadic onset have been identified when duplicated thumbs are accompanied by triple-jointed thumbs. Typical split thumbs are isolated malformations not associated with other malformation syndromes, with occasional reports of concomitant visceral malformations, especially hand-centered or Holt-Oram syndromes. 4. If the first baby has polydactyly, will the second baby also have polydactyly? The occurrence of polydactyly is mainly related to the influence of environmental factors, and has little relationship with heredity, and the probability of polydactyly occurring in the second child is very small. 5. Can the offspring of a patient with polydactyly also get the disease? The occurrence of polydactyly is mainly related to the influence of environmental factors, and it is generally believed that it has little to do with heredity. However, polydactyly (toe) deformity (especially some of the parents with the syndrome) genetic defects, the offspring for polydactyly (toe) deformity is slightly higher than the probability of normal people. 6. Do I need treatment for polydactyly? What are the effects of not treating it? Early examination by a doctor is generally ideal, but the examination is not an attempt to rush treatment, but rather to help parents address their concerns. Parents are often concerned about the appearance of the hand and its subsequent functioning and the chance of similar deformities occurring in siblings; they may also feel guilty. It is important to answer parents’ questions as best as possible to minimize their anxiety. Some polydactyly are unwilling to be removed due to personal reasons, customs, culture, religious beliefs, etc. We recommend aggressive surgical removal of these deformities. Each deformity has a different treatment plan and prognosis. Simple polydactyly does not greatly affect the function and development of the hand, but it affects the aesthetic appearance of the hand, and it will further affect the psychological development of the child starting from early childhood (after the age of 2 years), because after the age of 2 years the baby’s psychological development is gradually developing, and the baby already has a certain sense of its own abnormality, which will produce negative emotions such as low self-esteem. The negative emotions such as low self-esteem and lack of self-confidence in childhood may plant a shadow in his heart, which will have a certain impact on the baby’s future life and work. The tip of the superfluous finger (toe) is easy to twist and lead to necrosis and infection of the superfluous finger (toe). As for complex polydactyly, it will seriously affect the growth and development of the bones of the hand (foot) and its function, which will lead to finger bending deformity, small finger shape and weakening of strength, such as crab pincer-like polydactyly.