What is Postaxial polydactyly?

By: Casey DiazUpdated: February 18, 2021


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    May 19, 2022
Postaxial polydactyly is the duplication of the fifth digit and includes supernumerary digits that are fully developed with bone and neural tissue (type A) or that are attached only by soft tissue (type B). On examination in the neonatal unit, postaxial type B polydactyly was discovered on both of the newborn's hands.

In this regard, what gene causes polydactyly?

More than 40 mutations in the GLI3 gene have been found to cause Pallister-Hall syndrome, a rare condition whose major features include polydactyly, an abnormal growth in the brain called a hypothalamic hamartoma, and a malformation of the airway called a bifid epiglottis.

Subsequently, question is, what are the main symptoms of polydactyly?

Symptoms. The main symptom of polydactyly is an extra finger or toe. The condition can range from a small extra bump on the side of the hand to a finger that widens to end in two fingertips, an extra finger that dangles by a thin cord from the hand or a hand that has a thumb and five fingers.

Is polydactyly a genetic disorder?

Polydactyly may be passed down in families. This trait involves only one gene that can cause several variations. African Americans, more than other ethnic groups, can inherit a 6th finger. In most cases, this is not caused by a genetic disease.

What race is polydactyly most common in?

Isolated preaxial polydactyly in the hand is more common in Caucasians compared to African Americans, and has a high incidence in the Native American and Asian populations.


Does polydactyly cause harm?

For the most part, polydactyly is harmless to a cat's health and wellness.

Why is having six fingers a dominant trait?

Having more than five fingers is a little more complicated because it can be a dominant or recessive trait, depending on what genes are involved. If polydactyly is caused by just a single gene that only affects the number of fingers or toes and nothing else, then it is typically a dominant trait.

How is polydactyly diagnosed?

Polydactyly can be seen by ultrasound prenatally and by eye at birth. Your doctor will use x-rays to assess the underlying structure of your baby's finger and determine a course of treatment.

Is having 6 fingers genetic?

Having extra fingers or toes (6 or more) can occur on its own. There may not be any other symptoms or disease present. Polydactyly may be passed down in families. This trait involves only one gene that can cause several variations.

How does polydactyly affect a person's life?

Polydactyly happens when there is an abnormality in the process of the hand/foot splitting into separate fingers/toes while the baby is in the womb. Polydactyly alone very rarely affects a person's life expectancy; therefore, those who suffer from polydactyly are able to live as long as a person without the disorder.

How common is polydactyly in humans?

Polydactyly is Fairly Common & Very Treatable
About one in 500 people in the United States are affected by polydactyly, with it affecting both males and females at almost the same rate. People of Asian and Caucasian decent are more likely to have radial polydactyly.

What is the 6th finger called?

Six fingers or toes: The presence of an extra sixth finger or toe, a very common congenital malformation (birth defect). This condition is called hexadactyly. The word hexadactyly literally means six digits.

What chromosome does polydactyly affect?

Phenotype-Gene Relationships
Location Phenotype Gene/Locus MIM number
7p14.1 Polydactyly, postaxial, types A1 and B 165240

What is the prognosis of polydactyly?

For children with isolated polydactyly and syndactyly, the prognosis is excellent. After surgery most children will have full use of their fingers and toes.

Are extra digits hereditary?

The vast majority of occurrences of polydactyly are sporadic, meaning that the condition occurs without an apparent cause — while some may be due to a genetic defect or underlying hereditary syndrome. African-Americans are more likely to inherit the condition than other ethnic groups.

Are extra fingers functional?

It's really not uncommon for human babies to be born with extra fingers or toes. The mutation is called polydactyly, and around one in 500 babies has it. These extra digits are considered useless, and usually amputated not long after birth - but as new research has shown, they may not be quite so bad after all.

How can polydactyly be treated?

Treatment Options for Polydactyly
In most cases, doctors remove an extra finger or toe in early childhood. The goal of treatment is to give your child a hand or foot that works well and looks typical. There are also practical concerns, such as removing an extra toe so your child's foot fits well into shoes.