About ADSL | happyjack

What are the other Names for this Condition?

Adenylosuccinase Deficiency
ADSL Deficiency

What is Adenylosuccinate Lyase Deficiency? (Definition/Background Information)

Adenylosuccinate Lyase Deficiency (ADSL) is a rare genetic disorder characterized by adenlyosuccinate lyase enzyme deficiency
When such a deficiency occurs, the individual may have signs and symptoms similar to autism, improper/poor functioning of the muscles, psychological symptoms, and convulsions
ADSL is caused by mutations to the adenylosuccinate lyase (ADSL) gene, inherited in an autosomal recessive pattern. It can be diagnosed through a genetic test
There is no treatment for the condition, though medications help improve the quality of life. The prognosis of the condition is generally grim

Who gets Adenylosuccinate Lyase Deficiency? (Age and Sex Distribution)

Adenylosuccinate Lyase Deficiency is normally diagnosed during infancy. The symptoms are usually seen, within the first year of life
Individuals of all ages and both genders are affected by ADSL
Individuals of all race/ethnic background are prone to the condition

What are the Risk Factors for Adenylosuccinate Lyase Deficiency? (Predisposing Factors)

Inherited genetic defects are the most important risk factor of Adenylosuccinate Lyase Deficiency. Hence, individuals with a positive family history, are at an increased risk.

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones 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 Adenylosuccinate Lyase Deficiency? (Etiology)

Adenylosuccinate Lyase Deficiency is caused by mutations in the adenylosuccinate lyase (ADSL) gene on chromosome 22q
In many cases, these mutations are passed down through families, in an autosomal recessive pattern
The mutations, which have been so far identified, have all shown to cause structural instability in the enzyme

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 Adenylosuccinate Lyase Deficiency?

Signs and symptoms can vary greatly amongst individuals with Adenylosuccinate Lyase Deficiency. Some of these include:

Similarities to autism
Psychomotor delay
Epilepsy, seizures
Growth impairment
Muscle degeneration, low muscle tone and tension results in overall muscular weakness
Feeding problems, which includes difficulties in feeding

How is Adenylosuccinate Lyase Deficiency Diagnosed?

A diagnosis of Adenylosuccinate Lyase Deficiency would involve:

Physical exam with evaluation of family medical history
Genetic testing: By studying an individual’s DNA, mutations on the ADSL gene that cause ADSL can be identified, and a diagnosis made

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 Adenylosuccinate Lyase Deficiency?

Complications due to Adenylosuccinate Lyase Deficiency are quite common. They could include:

Short-stature, severe growth failure
Abnormal physical features, like small head circumference, flat occiput (back of the skull), small nose, thin upper lip, low set ears
Learning disabilities, learning may be slow with accompanying language delays

How is Adenylosuccinate Lyase Deficiency Treated?

Currently, there are no curative/definitive treatment options for Adenylosuccinate Lyase Deficiency. Measures are taken to improve the quality of life, by addressing the variety of signs and symptoms.

Some individuals have been given oral supplements of adenine and allopurinol, in order to ease the symptoms
Therapeutic trials with ribose and uridine are being implemented, though their effectiveness in reducing the symptoms, are yet to be established

How can Adenylosuccinate Lyase Deficiency be Prevented?

Currently there are no specific methods or guidelines to prevent Adenylosuccinate Lyase Deficiency genetic condition
Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
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

What is the Prognosis of Adenylosuccinate Lyase Deficiency? (Outcomes/Resolutions)

The prognosis of individuals with Adenylosuccinate Lyase Deficiency is grim. Most individuals die in their early infancy, or during childhood.

Additional and Relevant Useful Information for Adenylosuccinate Lyase Deficiency:

A defect in the adenlyosuccinate lyase enzyme is detected, if the presence of certain proteins, such as succinylaminoimidazole carboxamide riboside and succinyladenosine are detected in the cerebrospinal fluid, urine, and blood plasma. Such a positive test indicates a mutation in the ADSL gene. However, DNA testing is the definitive method for diagnosis of Adenylosuccinate Lyase Deficiency.

What are some Useful Resources for Additional Information?

National Organization for Rare Disorders (NORD)
55 Kenosia Avenue Danbury, CT 06813-1968
Phone: (203) 744-0100
Toll-Free: (800) 999-6673
Fax: (203) 798-2291
E-mail: orphan@rarediseases.org
Website: http://www.rarediseases.org

There are also 2 Facebook groups that we are aware of:

ADSL Deficiency Awareness and Research

Our Journey with ADSL Deficiency