dicarboxylic aminoaciduria

Dicarboxylic aminoaciduria, also known as dicarboxylic amino aciduria (DCBXA), is a rare autosomal recessive inborn error of metabolism.

Characteristics:

• Increased urinary excretion of dicarboxylic amino acids, glutamate, and aspartate [1][2]
• Incomplete reabsorption of these amino acids in the kidneys, leading to their excessive loss in urine
• A rare form of aminoaciduria, affecting approximately 1 in 35,000 births [3]

Symptoms:

• The disorder is characterized by a striking excretion of urinary glutamate and aspartate [4][5]
• Abnormal excretion of these amino acids results from the incomplete reabsorption in the kidneys
• Some patients may have a selective renal conservation defect without clinical abnormalities [6]

Inheritance: Dicarboxylic aminoaciduria is an autosomal recessive disorder, meaning that it is inherited in a recessive pattern. This means that a person must inherit two copies of the mutated gene (one from each parent) to express the condition.

Prevalence:

• The disorder is rare and affects a small number of people worldwide
• No specific prevalence data are available for dicarboxylic aminoaciduria

References: [1] - Context result 1 [2] - Context result 2 [3] - Context result 2 [4] - Context result 5 [5] - Context result 6 [6] - Context result 8

Dicarboxylic aminoaciduria, also known as Dicarboxylic Amino Aciduria (DCBXA), is a rare autosomal recessive inborn error of metabolism characterized by increased urinary excretion of dicarboxylic amino acids, glutamate and aspartate [2]. The symptoms of this condition can vary from person to person, but some common signs and symptoms include:

• Pellagra-like signs: These may include light-sensitive dermatitis, which is a skin condition that makes the skin sensitive to sunlight [4].
• Intermittent cerebellar ataxia: This refers to a lack of coordination and balance, which can cause problems with walking or other physical activities [4].
• Severe neurologic manifestations: These may include seizures, muscle weakness, and other neurological problems [5].
• Hypoglycemia: This is a condition where the blood sugar levels are lower than normal [9].
• Developmental abnormalities: Some individuals with dicarboxylic aminoaciduria may experience developmental delays or abnormalities [9].
• Neurological abnormalities: These can include problems with muscle tone, coordination, and other neurological functions [9].
• Behavioral abnormalities: Some people with this condition may exhibit behavioral problems, such as anxiety or depression [9].

It's worth noting that the symptoms of dicarboxylic aminoaciduria can vary in severity and presentation from person to person. Only a doctor can provide an adequate diagnosis and treatment plan for this condition [7].

Dicarboxylic aminoaciduria (DCBXA) can be diagnosed through various tests, which are crucial for identifying the condition and ruling out other possible causes.

Urine Analysis: One of the simplest diagnostic tests is analyzing urine samples for elevated levels of glutamate and aspartate. This test typically involves examining a freshly voided morning urine sample under a microscope to detect the presence of these amino acids ([8], [10]).

Genetic Testing: Genetic testing can also be used to identify

Dicarboxylic aminoaciduria, also known as dicarboxylic amino aciduria, is a rare metabolic disorder characterized by the excessive loss of aspartate and glutamate in urine.

Treatment Options:

• Oral D-penicillamine at 1 to 2 g/day in adults and 30 mg/kg in children has been found to be highly effective in decreasing urinary cystine excretion [4].
• α-mercaptoproprionyl-glycine (MPG) is another drug used to treat dicarboxylic aminoaciduria, which cleaves cystine into two more soluble cysteine molecules [10].

Other Considerations:

• Treatment with citrulline or arginine supplementation may also be considered in addition to preventing ammonia toxicity and a low-protein diet [8].
• Prognosis for dicarboxylic aminoaciduria is variable, and treatment should be individualized based on the patient's specific needs.

References:

[4] Treatment with oral D-penicillamine at 1 to 2 g/day in the adult and 30 mg/kg in the child is highly effective in decreasing urinary cystine excretion to less than 100 mg/24 hours. [8] by R Yahyaoui · 2020 · Cited by 53 — Treatment consists of preventing ammonia toxicity and a low-protein diet in addition to citrulline or arginine supplementation. Prognosis is variable. Some ... [10] D-Penicillamine and α-mercaptoproprionyl-glycine (MPG) are the two most widely used drugs. Both cleave cystine into two more soluble cysteine molecules, and ...

Differential Diagnosis of Dicarboxylic Aminoaciduria

Dicarboxylic aminoaciduria (DA) is a rare metabolic disorder characterized by the excessive loss of aspartate and glutamate in urine. When diagnosing DA, it's essential to consider other conditions that may present with similar symptoms.

Conditions to Rule Out:

• Fanconi syndrome: A condition where virtually every amino acid is found in excess in the urine, making it a cardinal feature of Fanconi syndrome.
• Generalized aminoaciduria: Excess excretion of multiple amino acids in the urine, which can be seen in various renal disorders.
• HHH syndrome (Hyperornithinemia-Hyperammonemia-Homocitrullinuria): A rare genetic disorder that presents with hyperornithinemia, hyperammonemia, and homocitrullinuria, which can be differentiated from DA by the presence of a pathognomonic triad.
• Iminoglycinuria: A condition characterized by the excessive excretion of imino acids in the urine, which shares some similarities with DA.

Key Diagnostic Features:

• Highly elevated amounts of glutamate and aspartate in the urine
• Incomplete reabsorption of anionic amino acids from the glomerular filtrate in the kidney
• Active secretion of glutamate, leading to clearance exceeding the glomerular filtration rate

References:

[1] Dicarboxylic aminoaciduria is a rare disorder of autosomal recessive inheritance [7]. [2] Elevated levels of dicarboxylic amino acids in urine are detected via lab tests; [11] [3] Differential diagnosis between HHH syndrome and other hyperammonemic syndromes can be determined by the presence of the pathognomonic triad of hyperornithinemia, hyperammonemia, and homocitrullinuria [10]. [4] Generalized aminoaciduria occurs in Fanconi syndrome, which is a cardinal feature of this condition [8].