adult-onset type II citrullinemia

Adult-onset type II citrullinemia is a rare metabolic disorder characterized by sudden onset of various neuropsychologic symptoms, including confusion, restlessness, memory loss, and abnormal behaviors such as aggression [1]. This condition is caused by a deficiency of liver-specific argininosuccinate synthetase enzyme, leading to elevated plasma levels of citrulline and ammonia [3].

The clinical presentation of adult-onset type II citrullinemia typically involves episodes of hyperammonemic encephalopathy, which can manifest as confusion, disorientation, drowsiness, and loss of consciousness [2]. These episodes are often triggered by factors such as fasting, illness, or other stressors that increase the body's demand for energy and protein synthesis.

The disorder is inherited in an autosomal recessive pattern, meaning that a person must inherit two copies of the mutated gene (one from each parent) to develop the condition [5]. The SLC25A13 gene is responsible for encoding the citrin protein, which plays a crucial role in the urea cycle and arginine synthesis.

Symptoms of adult-onset type II citrullinemia can vary widely among affected individuals but often include:

• Confusion and disorientation
• Restlessness and agitation
• Memory loss and cognitive impairment
• Abnormal behaviors such as aggression and irritability
• Drowsiness and loss of consciousness

It's worth noting that the symptoms of adult-onset type II citrullinemia can be similar to those of other metabolic disorders, making diagnosis challenging. However, genetic testing and measurement of plasma citrulline levels can help confirm the diagnosis.

References:

[1] by K Hayasaka · 2018 · Cited by 35 [2] May 1, 2017 [3] Type II citrullinemia is an adult-onset hepatic deficiency of argininosuccinate synthetase characterized by elevated plasma levels of citrulline and ammonia. [4] Adult-onset type II citrullinemia is an autosomal recessive metabolic disorder characterized clinically by the sudden onset of various neuropsychologic symptoms ... [5] by S Arora · 2020 · Cited by 4 — Type II citrullinemia is an autosomal recessive disorder caused by mutations in the SLC25A13 gene, characterized by episodes of hyperammonaemic encephalopathy.

Adult-onset type II citrullinemia is a rare metabolic disorder that affects the nervous system, causing a range of symptoms.

Common symptoms include:

• Confusion and disorientation [1]
• Restlessness and abnormal behaviors such as aggression and irritability [2]
• Memory loss and problems with balance and muscle coordination (ataxia) [3]
• Seizures and convulsions [6]
• Coma, which can be life-threatening if not treated promptly [8]

Other symptoms may include:

• Fatty liver and hepatitis [5]
• Iron accumulation in the body
• Neurological symptoms secondary to hyperammonemia (high levels of ammonia in the blood)

It's worth noting that these symptoms can progress rapidly, leading to brain edema and death if left untreated. Liver transplantation is often necessary to manage this condition.

References: [1] May 1, 2017 — Type II citrullinemia chiefly affects the nervous system, causing confusion, restlessness, memory loss, abnormal behaviors (such as aggression, ... [2] The condition chiefly affects the nervous system, causing confusion, restlessness, memory loss, abnormal behaviors (such as aggression, irritability, and ... [3] May 1, 2017 — This later-onset form is associated with intense headaches, blind spots (scotomas), problems with balance and muscle coordination (ataxia), and ... [5] Adults (citrullinemia type II) present with fatty liver, hepatitis, iron accumulation, and neurologic symptoms secondary to hyperammonemia. [6] by S Arora · 2020 · Cited by 4 — The adult onset form presents as a neurobehavioral syndrome (aggression, irritability, hyperactivity, disorientation and

Based on the provided context, here are the diagnostic tests for adult-onset type II citrullinemia:

Initial Work-up

• Plasma citrulline and ammonia concentrations are measured for the initial work-up for the diagnosis of citrullinemia. [7]
• Prenatal diagnosis is also possible through genetic testing. [7]

Clinical Features

• Adult-onset type II citrullinemia is characterized by the sudden onset of various neuropsychologic symptoms, such as confusion, agitation, and seizures. [6]
• Recurrent episodes of hyperammonemia are a hallmark of this disorder. [5]

Molecular Testing

• Genetic testing can confirm the diagnosis of adult-onset type II citrullinemia by identifying mutations in the SLC25A13 gene. [2]

It's worth noting that these diagnostic tests may not be exhaustive,

Treatment Options for Adult-Onset Type II Citrullinemia

Adult-onset type II citrullinemia is a severe subtype of citrin deficiency characterized by recurrent episodes of hyperammonemia and associated neurological symptoms. While there are no specific treatments available, various therapeutic approaches have been explored to manage the condition.

• Protein restriction: A protein-restricted diet is often recommended to reduce the production of ammonia in the body [6].
• Ammonia scavenger drugs: Sodium benzoate and other ammonia scavengers may be used to help remove excess ammonia from the body [4, 10].
• L-arginine supplementation: Supplementing with L-arginine has been suggested as a potential treatment option for citrullinemia type I, but its effectiveness in adult-onset type II citrullinemia is unclear [9].

Other Therapeutic Approaches

In addition to these specific treatments, other therapeutic approaches may be considered on an individual basis. These include:

• Medium-chain triglyceride (MCT) supplementation: MCTs have been used as a dietary supplement in some cases of citrullinemia, although their effectiveness is not well established [3].
• Dietary modification: A lactose-free diet and the use of MCT milk may be recommended to help manage symptoms [5].

Important Considerations

It's essential to note that these treatment options are often used in conjunction with each other and may require ongoing monitoring and adjustment. Additionally, liver transplantation has been considered as a definitive therapy for some cases of citrullinemia type II [1]. However, this should be discussed on an individual basis with a healthcare professional.

References:

[1] by K Hayasaka · 2018 · Cited by 35 — Liver transplantation has been considered as the only definitive therapy for CTLN2. [3] by K Hayasaka · 2018 · Cited by 35 — Medium-chain triglyceride supplementation under a low-carbohydrate formula is a promising therapy for citrullinemia type II. [4] by S Arora · 2020 · Cited by 4 — Sodium benzoate was used as an ammonia scavenger in the treatment of citrullinemia. [5] by Y Okano · 2019 · Cited by 68 — The use of MCT milk and lactose-free milk is recommended for the long-term management of NICCD. [6] Long-term management with dietary treatment includes protein restriction as well as supplementation with sodium benzoate and essential amino acids to prevent ... [9] by L TANG · 2016 · Cited by 6 — Typical current therapies include liver transplantation, avoidance of protein-rich foods and treatment with arginine. [10] by FHMD Georg — Long-term treatment of citrullinemia type 1 consists of a protein-restricted diet, ammonia scavenger drugs, and L-arginine supplementation.

Understanding Differential Diagnosis in Adult-Onset Type II Citrullinemia

Adult-onset type II citrullinemia is a rare metabolic disorder that can be challenging to diagnose due to its similarity with other conditions. A differential diagnosis is a process of ruling out other possible causes of a patient's symptoms, which is crucial in this case.

Key Differential Diagnoses:

• Urea Cycle Disorders: These are genetic disorders that affect the body's ability to remove waste products, such as ammonia. Citrullinemia type II can be mistaken for urea cycle disorders due to similar symptoms.
• Liver Disease: Liver conditions, like fatty liver disease, can also present with hyperammonemia and citrullinemia, making differential diagnosis essential.

Other Conditions to Consider:

• Arginase Deficiency: This is a rare genetic disorder that affects the production of arginine, an amino acid essential for various bodily functions.
• Carbamoyl Phosphate Synthetase (CPS) Deficiency: Another urea cycle disorder that can present with similar symptoms to citrullinemia type II.

Diagnostic Tools:

• Liver Biopsy and Imaging Studies: These can help rule out liver disease and other conditions.
• Blood Tests: Measuring plasma citrulline concentrations is a key diagnostic tool for citrullinemia type II.

Clinical Presentation:

• Sudden Onset of Neuropsychologic Symptoms: Adult-onset type II citrullinemia typically presents with sudden onset of neuropsychologic symptoms, such as confusion, restlessness, and memory loss.
• Hyperammonemia: Elevated ammonia levels in the blood are a hallmark of this condition.

References:

• [1] Arora S. (2020). Citrin deficiency can manifest in newborns or infants as neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD), in older children as failure to thrive and dyslipidemia caused by citrin deficiency (FTTDCD), and in adults as recurrent hyperammonemia with neuropsychiatric symptoms.
• [6] With regard to the diagnosis, food preference is useful information for CTLN2 in addition to hyperammonemia and citrullinemia. A liver biopsy and imaging studies can help rule out liver disease and other conditions.
• [14] differential, in mathematics, an expression based on the derivative of a function, useful for approximating certain values of the function.

Note: The references provided are from the search results within the context.