Summary about Disease
Xanthine oxidase deficiency is a rare genetic disorder that results in a buildup of xanthine and hypoxanthine in the blood and urine. This occurs because the enzyme xanthine oxidase, which is responsible for breaking down these substances, is either absent or not functioning properly. There are two types: Type I, caused by a deficiency in the enzyme itself, and Type II, caused by a deficiency in a molybdenum cofactor necessary for the enzyme's function.
Symptoms
Many individuals with xanthine oxidase deficiency are asymptomatic. When symptoms are present, they can include:
Xanthine kidney stones (leading to urinary tract infections, pain, and hematuria)
Muscle pain or stiffness (myalgia)
Arthralgia (joint pain)
In rare cases, xanthine deposits in muscles
Causes
Xanthine oxidase deficiency is caused by mutations in genes responsible for either the xanthine oxidase enzyme itself or the molybdenum cofactor required for its activity. It is inherited in an autosomal recessive pattern, meaning that both parents must carry a copy of the mutated gene for a child to be affected. Specific genes involved are MOCOS or *XDH*.
Medicine Used
There is no specific medication to directly replace the deficient xanthine oxidase enzyme. Treatment focuses on managing symptoms and preventing complications.
Allopurinol is not used. It can actually exacerbate the condition by further increasing hypoxanthine levels.
Hydration: Maintaining adequate fluid intake to help prevent xanthine stone formation.
Dietary Modifications: Low-purine diet is recommended to reduce the production of xanthine and hypoxanthine.
Is Communicable
No, xanthine oxidase deficiency is not communicable. It is a genetic disorder and cannot be spread from person to person.
Precautions
Genetic counseling is recommended for families with a history of xanthine oxidase deficiency.
Maintain a low-purine diet as recommended by a doctor.
Ensure adequate fluid intake.
Regular monitoring of kidney function is important.
Avoid medications that could worsen symptoms or interfere with treatment.
How long does an outbreak last?
Xanthine oxidase deficiency is a chronic condition, not an outbreak. Symptoms, such as kidney stones, may occur intermittently and may need management at the time of occurrence.
How is it diagnosed?
Diagnosis involves:
Urine Analysis: Detecting elevated levels of xanthine and hypoxanthine.
Blood Tests: Elevated xanthine and hypoxanthine levels in the blood.
Enzyme Assay: Measurement of xanthine oxidase activity in a liver or intestinal biopsy sample (rarely done).
Genetic Testing: Confirming the diagnosis by identifying mutations in the MOCOS or *XDH* genes.
Timeline of Symptoms
The onset and progression of symptoms can vary significantly:
Infancy/Childhood: Some individuals may develop xanthine stones in childhood.
Adulthood: Some individuals may remain asymptomatic throughout their lives, while others may develop symptoms later in life.
Variable: The timing and severity of symptoms are highly variable.
Important Considerations
Early diagnosis and management are crucial to prevent kidney damage.
Lifelong dietary management and adequate hydration are essential.
Individuals with xanthine oxidase deficiency should inform their healthcare providers about their condition, especially before starting any new medications.
Patients should be monitored for the presence of xanthine stones.