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

• Ulna Hypoplasia
• Ulnar Hypoplasia
• Upper Limb Mesomelic Dysplasia

What is Fryns Hofkens Fabry Syndrome? (Definition/Background Information)

• Fryns Hofkens Fabry Syndrome is an isolated upper limb mesomelic dysplasia
• It has been described in four patients from two unrelated families (a man and his daughter, and a Lebanese man and his son)
• Patients present with ulnar hypoplasia with severe radial bowing, but normal stature
• The mode of transmission is likely to be autosomal dominant with variable expressivity

(Source: Fryns Hofkens Fabry Syndrome; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

Who gets Fryns Hofkens Fabry Syndrome? (Age and Sex Distribution)

• Fryns Hofkens Fabry Syndrome is an extremely rare congenital disorder, described thus far only in four individuals belonging to two different families (two affected individuals in each family)
• The presentation of symptoms may occur at birth
• Both males and females may be affected

What are the Risk Factors for Fryns Hofkens Fabry Syndrome? (Predisposing Factors)

• A positive family history may be an important risk factor, since Fryns Hofkens Fabry Syndrome can be reportedly inherited
• Being a child of consanguineous parents may be a risk factor for the disorder as well

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 Fryns Hofkens Fabry Syndrome? (Etiology)

• The genetic cause of Fryns Hofkens Fabry Syndrome is not known at the present time
• It has been suggested that the condition is inherited in an autosomal dominant manner, with variable expressivity

Autosomal dominant: Autosomal dominant conditions are traits or disorders that are present when only one copy of the mutation is inherited on a non-sex chromosome. In these types of conditions, the individual has one normal copy and one mutant copy of the gene. The abnormal gene dominates, masking the effects of the correctly function gene. If an individual has an autosomal dominant condition, the chance of passing the abnormal gene on to their offspring is 50%. Children, who do not inherit the abnormal gene, will not develop the condition or pass it on to their offspring.

When an autosomal dominant trait has variable expressivity and penetrance, it indicates that the onset of disease symptoms in an affected individual is not determined by the mutated gene alone, but influenced by environmental and lifestyle choices as well.

What are the Signs and Symptoms of Fryns Hofkens Fabry Syndrome?

The signs and symptoms of Fryns Hofkens Fabry Syndrome may include:

• Distal ulnar hypoplasia
• Dysplastic radii
• Hypoplasia of the ulna
• Hypoplasia of the radius
• Radial bowing
• Mesomelic arm shortening
• Ulnar deviation of the hand
• Ulnar deviation of finger

(Source: Fryns Hofkens Fabry Syndrome; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

How is Fryns Hofkens Fabry Syndrome Diagnosed?

Fryns Hofkens Fabry Syndrome 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 Fryns Hofkens Fabry Syndrome?

The complications of Fryns Hofkens Fabry Syndrome may include:

• Limited movement of elbows
• Dislocation of radial heads and resultant pain

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

How is Fryns Hofkens Fabry Syndrome Treated?

There is no cure for Fryns Hofkens Fabry Syndrome, since it is a genetic condition. The treatment is usually given to manage the signs and symptoms and any complications that develops.

How can Fryns Hofkens Fabry Syndrome be Prevented?

Currently, Fryns Hofkens Fabry Syndrome 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 Fryns Hofkens Fabry Syndrome? (Outcomes/Resolutions)

• The prognosis of Fryns Hofkens Fabry Syndrome 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 Fryns Hofkens Fabry Syndrome:

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

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