What are the other Names for this Condition? (Also known as/Synonyms)

• Split Hand Foot Deformity 2 (SHFD2)
• Split Hand Foot Malformation 2 (SHFM2)
• X-Linked Split Hand Foot Anomaly

What is X-Linked Split Hand/Foot Malformation? (Definition/Background Information)

• X-Linked Split Hand/Foot Malformation (SHFM) is a type of birth defect that consists of missing digits (fingers and/or toes), a deep cleft down the center of the hand or foot, and fusion of remaining digits. The severity of this condition varies widely among affected individuals
• At least six different forms of isolated SHFM have been described. Each type is associated with a different underlying genetic cause. The X-Linked Split Hand/Foot Malformation or type 2 SHFM (SFHM 2) is caused by changes to the X chromosome, and inherited in an X-linked manner 

(Source: X-Linked Split Hand/Foot Malformation; Genetic and Rare Disease Information Center (GARD) of National Center for Advancing Translational Science (NCATS), USA.)

Who gets X-Linked Split Hand/Foot Malformation? (Age and Sex Distribution)

• X-Linked Split Hand/Foot Malformation is a rare congenital disorder. The presentation of symptoms may occur at birth or in infancy
• The condition predominantly affects males. However, some females with the defective causative gene on an X chromosome may develop mild symptoms
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for X-Linked Split Hand/Foot Malformation? (Predisposing Factors)

• A positive family history may be an important risk factor, since X-Linked Split Hand/Foot Malformation can be inherited
• Currently, no other risk factors have been clearly identified for the disorder

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of X-Linked Split Hand/Foot Malformation? (Etiology)

• X-Linked Split Hand/Foot Malformation is caused by mutation(s) in the X chromosome. The exact causative gene for this condition has not been identified
• The condition is inherited in an X-linked recessive manner

(Source: X-Linked Split Hand/Foot Malformation; Genetic and Rare Disease Information Center (GARD) of National Center for Advancing Translational Science (NCATS), USA.)

X-linked recessive pattern of inheritance: The gene associated with this condition is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder. Because it is unlikely that females will have two altered copies of this gene, males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons.

What are the Signs and Symptoms of X-Linked Split Hand/Foot Malformation?

The signs and symptoms of X-Linked Split Hand/Foot Malformation may vary among affected individuals in type and severity and include the following:

• Finger syndactyly
• Short metacarpal
• Short phalanx of finger
• Split foot
• Split hand

(Source: X-Linked Split Hand/Foot Malformation; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

How is X-Linked Split Hand/Foot Malformation Diagnosed?

X-Linked Split Hand/Foot Malformation is diagnosed on the basis of the following information:

• Complete physical examination
• Thorough medical history evaluation
• Assessment of signs and symptoms
• Laboratory tests
• Imaging studies
• Biopsy studies, if necessary

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of X-Linked Split Hand/Foot Malformation?

The complications of X-Linked Split Hand/Foot Malformation may include:

• Inability to grip or hold objects
• Difficulty with walking
• Low self-esteem

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is X-Linked Split Hand/Foot Malformation Treated?

There is no cure for X-Linked Split Hand/Foot Malformation, since it is a genetic condition. The treatment is usually given to manage the signs and symptoms and any complication that develops.

How can X-Linked Split Hand/Foot Malformation be Prevented?

X-Linked Split Hand/Foot Malformation may not be preventable, since it is a genetic disorder.

• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders
• Regular medical screening at periodic intervals with tests and physical examinations are recommended

What is the Prognosis of X-Linked Split Hand/Foot Malformation? (Outcomes/Resolutions)

• The prognosis of X-Linked Split Hand/Foot Malformation is dependent upon the severity of the signs and symptoms and associated complications, if any
• Individuals with mild conditions have better prognosis than those with severe symptoms and complications
• Typically, the prognosis may be assessed on a case-by-case basis

Additional and Relevant Useful Information for X-Linked Split Hand/Foot Malformation:

The following DoveMed website link is a useful resource for additional information:

http://www.dovemed.com/diseases-conditions/rare-disorders/