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

• Hypervalinemia
• Valine Transaminase Deficiency Disorder

What is Valinemia? (Definition/Background Information)

• Valinemia is a very rare metabolic disorder characterized by abnormally high levels of the amino acid valine in blood and urine
• Valinemia is caused by a deficiency of the enzyme valine transaminase, which is needed for the breakdown (metabolism) of valine in the body
• It is inherited in an autosomal recessive manner, although the gene responsible for the condition is not yet known
• Infants with Valinemia reportedly experience lack of appetite, vomiting, and failure to thrive. In some cases, the condition may be life-threatening
• Low muscle tone (hypotonia), excessive drowsiness, hyperactivity, and developmental delay have also been reported
• Treatment includes a diet low in valine (introduced during early infancy) which usually improves symptoms and brings valine levels to normal

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

Who gets Valinemia? (Age and Sex Distribution)

• Valinemia is a rare congenital disorder. The presentation of symptoms may occur at birth
• Both males and females may be affected
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Valinemia? (Predisposing Factors)

• A positive family history may be an important risk factor, since Valinemia can be inherited

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 Valinemia? (Etiology)

• Valinemia is caused by a deficiency of the enzyme valine transaminase, which is needed for the breakdown (metabolism) of valine in the body
• It is inherited in an autosomal recessive manner, although the gene responsible for the condition is not yet known

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

Autosomal recessive: 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 Valinemia?

The signs and symptoms of Valinemia may include:

• Lack of appetite
• Protein intolerance
• Metabolic acidosis
• Frequent vomiting
• Abnormally low muscle tone (hypotonia)
• Hyperkinesia
• Hyperactivity
• Excessive drowsiness 
• Delayed mental and physical development

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

How is Valinemia Diagnosed?

Valinemia 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 Valinemia?

The complications of Valinemia may include:

• Inadequate weight gain
• Delay in reaching developmental milestones
• Coma
• Failure to thrive

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

How is Valinemia Treated?

• Due to the rarity of Valinemia, information about treatment in the medical literature is very limited
• A diet low in valine introduced during early infancy is thought to improve symptoms of the condition and lower valine concentrations in the blood to normal levels

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

How can Valinemia be Prevented?

Valinemia 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 Valinemia? (Outcomes/Resolutions)

• The prognosis of Valinemia is dependent upon the severity of the signs and symptoms and associated complications, if any
• A low valine diet may help reduce severe symptoms and avoid complications

Additional and Relevant Useful Information for Valinemia:

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

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