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

• Parchment Right Ventricle
• Uhl's Anomaly

What is Uhl Anomaly? (Definition/Background Information)

• Uhl Anomaly is characterized by an almost complete absence of the myocardium in the right ventricle resulting in a thin walled nonfunctional right ventricle manifesting with cardiac arrhythmias and right ventricular failure
• Cases of partial absence of right ventricular myocardium which remains asymptomatic or mildly symptomatic until adulthood have also been reported
• Patients presenting with complete Uhl Anomaly should be considered for cardiac transplantation

(Source: Uhl Anomaly; Genetic and Rare Disease Information Center (GARD) of National Center for Advancing Translational Science (NCATS), USA.)

Who gets Uhl Anomaly? (Age and Sex Distribution)

• Uhl’s Anomaly is an extremely rare congenital disorder. The onset of symptoms may occur at birth or in infancy
• Bothe genders may be affected by this disorder

What are the Risk Factors for Uhl Anomaly? (Predisposing Factors)

• A positive family history may be an important risk factor, since Uhl Anomaly can be reportedly inherited in rare cases
• Currently, no other risk factors have been clearly identified for this condition

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 Uhl Anomaly? (Etiology)

Presently, the exact cause of Uhl Anomaly is not known.

• Genetic factors and environmental factors may play a role in the development of this condition
• Most cases are sporadic in nature, and occur in individuals with no family history of the condition

The following are some possible causes of Uhl Anomaly:

• Exposure to environmental toxins or pathogens may cause this condition
• Selective apoptosis or non-development of cardiomyocytes leading to absence of myocardium in the right ventricle
• Overexpression of vascular endothelial growth by cardiomyocytes may lead to non-development of the ventricular myocardium
• A mutation in an as yet unidentified gene: This may occur in cases where the condition is familial (occurs in siblings). The condition may either be transmitted in an autosomal recessive manner, or autosomal dominant manner with incomplete penetrance

Autosomal dominant inheritance: 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.

In autosomal dominant inheritance with reduced or incomplete penetrance, an individual may not develop symptoms even when he/she is carrying a defective gene copy in each cell of his/her body. It is believed that factors other than gene mutation(s) contribute to the development of the disease.

Autosomal recessive inheritance: Autosomal recessive conditions are traits or disorders that occur when two copies of an abnormal gene have been inherited on a non-sex chromosome. If both parents have an autosomal recessive condition, there is a 100% likelihood of passing on the mutated genes to their children. If, however, only one mutant copy of the gene is inherited, the individual will be a carrier of the condition, but will not be present with any symptoms. Children born to two carriers, have a 25% chance of being homozygous dominant (unaffected), a 50% chance of being heterozygous (carrier), and a 25% chance of being homozygous recessive (affected).

What are the Signs and Symptoms of Uhl Anomaly?

The signs and symptoms of Uhl Anomaly may include:

• Right ventricular cardiomyopathy
• Ventricular arrhythmia

(Source: Uhl Anomaly; Genetic and Rare Disease Information Center (GARD) of National Center for Advancing Translational Science (NCATS), USA.)

How is Uhl Anomaly Diagnosed?

Uhl Anomaly 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 (Echiocardiography)
• 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 Uhl Anomaly?

The complications of Uhl Anomaly may include:

• Congestive heart failure
• Reduced quality of life

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

How is Uhl Anomaly Treated?

The treatment for Uhl Anomaly may include the following:

• Drugs for controlling arrhythmias
• Drainage of effusions from the pericardial, pleural or peritoneal cavities
• Surgical repair of the anomaly
• Heart transplantation

How can Uhl Anomaly be Prevented?

• Uhl Anomaly may not be preventable, since it is a congenital disorder
• 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 Uhl Anomaly? (Outcomes/Resolutions)

• The prognosis of Uhl Anomaly 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 Uhl Anomaly:

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

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