How is Argininosuccinase deficiency treated?
Intravenous benzoate, arginine, and phenylacetate administration may be indicated as initial therapy for hyperammonemia, but such combined therapy is appropriate only prior to specific diagnosis. Hemodialysis, if available, reduces the blood ammonia levels more efficiently and quickly.
What is argininosuccinate lyase deficiency?
Defect: Argininosuccinate Lyase (ASL) Deficiency, also known as Argininosuccinic Aciduria (AA), is the result of a mutated or deficient argininosuccinate lyase enzyme. This defective or deficient enzyme leads to inadequate ureagenesis, accumulation of argininosuccinic acid, and deficient endogenous arginine production.
Which enzyme is deficient in Citrullinemia?
Citrullinemia type I (CTLN1) is a rare autosomal recessive genetic disorder that includes a neonatal acute (classic) form, a milder late-onset form, a form that begins during or after pregnancy, and an asymptomatic form. CTLN1 is caused by deficiency or absence of the enzyme argininosuccinate synthetase (ASS).
How common is Argininosuccinate lyase deficiency?
Prevalence. The estimated prevalence is 1:70,000 to 1:218,000 live births [Brusilow & Horwich 2001, NORD]. However, ASL deficiency is very likely underdiagnosed, making it difficult to assess the true frequency in the general population.
What causes aciduria?
Argininosuccinic aciduria is caused by alterations (mutations) in the ASL gene. Genes provide instructions for creating proteins that play a critical role in many functions of the body. When a mutation of a gene occurs, the protein product may be faulty, inefficient, or absent.
What are the symptoms of arginine deficiency?
Symptoms
- Poor growth (present in all the people who have arginase deficiency)
- Stiff muscles and increased reflexes ( spasticity )
- Developmental delay.
- Loss of previously acquired developmental milestones.
- Intellectual disability.
- Seizures.
- Small head size ( microcephaly )
- Problems with balance and coordination.
What causes l-arginine deficiency?
In principle, there are three conditions that could result in arginine deficiency: dietary deficiency of arginine either by starvation or by ingesting a diet severely deficient in arginine (although the latter has not been found to result in arginine deficiency in healthy adults), increased catabolism of arginine.
Why is arginine given in Citrullinemia?
Treatment. There are multiple treatment methods. Low protein diets, are intended to minimize production of ammonia. Arginine, sodium benzoate and sodium phenylacetate help to remove ammonia from the blood.
Is Citrullinemia treatable?
Treatment includes removal of ammonia in the blood by medications and dialysis , as well as a lifelong low- protein diet. Liver transplantation is possible and, if done early in life, may eliminate the symptoms of the disorder.
Deficiency of argininosuccinate lyase (ASL), the enzyme that cleaves argininosuccinic acid to produce arginine and fumarate in the fourth step of the urea cycle, is characterized by a severe neonatal onset form and a late onset form.
What are the clinical characteristics of arginine deficiency in urea?
Clinical characteristics: Deficiency of argininosuccinate lyase (ASL), the enzyme that cleaves argininosuccinic acid to produce arginine and fumarate in the fourth step of the urea cycle, may present as a severe neonatal-onset form and a late-onset form:
What are the signs and symptoms of arginase deficiency?
The first features of arginase deficiency often appear between the ages of one and three years. In some cases, symptoms may begin earlier or later. Occasionally, people with arginase deficiency have episodes of severe buildup of ammonia in the blood (hyperammonemia).
What is the role of argininosuccinate lyase in urea cycle?
This enzyme is one of six enzymes that play a role in the breakdown and removal of nitrogen from the body, a process known as the urea cycle. The lack of this argininosuccinate lyase results in excessive accumulation of nitrogen, in the form of ammonia (hyperammonemia), in the blood.
