ICD-10: E72.11

Homocystinuria is a rare genetic disorder characterized by the accumulation of homocysteine in the body due to a deficiency in the enzyme cystathionine beta-synthase (CBS). The diagnosis of homocystinuria, particularly for the ICD-10 code E72.11, involves several criteria and diagnostic steps.

Diagnostic Criteria for Homocystinuria

1. Clinical Symptoms

Patients with homocystinuria may present with a variety of clinical symptoms, which can include:
- Ocular abnormalities: Such as lens dislocation (ectopia lentis) and myopia.
- Skeletal features: Including tall stature, scoliosis, and osteoporosis.
- Neurological issues: Such as developmental delays, seizures, and psychiatric disorders.
- Vascular complications: Increased risk of thromboembolic events due to elevated homocysteine levels.

2. Biochemical Testing

The diagnosis is confirmed through biochemical tests that measure the levels of homocysteine and related metabolites in the blood and urine:
- Plasma homocysteine levels: Elevated levels of homocysteine in the blood are indicative of the disorder.
- Urinary homocysteine: Increased excretion of homocysteine in urine can also support the diagnosis.

3. Genetic Testing

Genetic testing is crucial for confirming the diagnosis of homocystinuria:
- Mutation analysis: Identification of mutations in the CBS gene is definitive for diagnosing classical homocystinuria. This can be performed through sequencing techniques.

4. Newborn Screening

In many regions, newborn screening programs include tests for homocystinuria:
- Initial screening: Typically involves measuring amino acid levels in dried blood spots. Elevated methionine levels can indicate a risk for homocystinuria, prompting further testing.

5. Family History

A detailed family history is important, as homocystinuria is inherited in an autosomal recessive manner. A family history of similar symptoms or confirmed cases can support the diagnosis.

Conclusion

The diagnosis of homocystinuria (ICD-10 code E72.11) is multifaceted, involving clinical evaluation, biochemical testing, genetic analysis, and sometimes newborn screening. Early diagnosis is crucial for management and treatment, which can significantly improve outcomes for affected individuals. If you suspect homocystinuria, it is essential to consult a healthcare professional for appropriate testing and diagnosis.

Homocystinuria, classified under ICD-10-CM code E72.11, is a rare genetic disorder characterized by the accumulation of homocysteine in the body due to a deficiency in one of the enzymes involved in its metabolism. This condition is primarily linked to a defect in the enzyme cystathionine beta-synthase (CBS), which is crucial for converting homocysteine to cystathionine, a precursor to cysteine.

Clinical Features

Symptoms

Individuals with homocystinuria may present a variety of symptoms, which can vary widely in severity. Common clinical manifestations include:

• Neurological Symptoms: These may include developmental delays, intellectual disability, and psychiatric disorders.
• Ocular Symptoms: Patients often experience lens dislocation (ectopia lentis), myopia, and an increased risk of glaucoma.
• Skeletal Abnormalities: Features may include tall stature, long limbs, and a slender build, often resembling Marfan syndrome.
• Vascular Complications: There is an increased risk of thromboembolic events, such as deep vein thrombosis and pulmonary embolism, due to elevated homocysteine levels affecting vascular integrity.

Diagnosis

Diagnosis of homocystinuria typically involves:

• Biochemical Testing: Elevated levels of homocysteine in the urine and plasma are indicative of the disorder.
• Genetic Testing: Identification of mutations in the CBS gene can confirm the diagnosis.
• Family History: A thorough family history may reveal patterns of inheritance, as homocystinuria is inherited in an autosomal recessive manner.

Prevalence

The prevalence of classical homocystinuria is estimated to be approximately 1 in 200,000 to 1 in 300,000 live births, although this can vary by population and geographic region[3].

Management

Management of homocystinuria focuses on reducing homocysteine levels and preventing complications. Treatment strategies may include:

• Dietary Modifications: A low-methionine diet can help reduce homocysteine levels. Methionine is an amino acid that contributes to homocysteine production.
• Vitamin Supplementation: High doses of vitamin B6 (pyridoxine) may be beneficial for some patients, particularly those with responsive forms of the disorder. Additionally, folate and vitamin B12 supplementation can aid in homocysteine metabolism.
• Medications: Betaine, a compound that can help lower homocysteine levels, may be prescribed in some cases.

Conclusion

Homocystinuria is a serious metabolic disorder that requires early diagnosis and comprehensive management to mitigate its complications. Awareness of its clinical features and the importance of genetic counseling is crucial for affected families. Regular monitoring and a multidisciplinary approach involving dietitians, geneticists, and other healthcare professionals are essential for optimal patient outcomes.

For further information on the clinical policy regarding homocysteine testing and management strategies, healthcare providers can refer to specific clinical guidelines and resources available in the medical literature[2][4].

Homocystinuria, classified under ICD-10 code E72.11, is a rare genetic disorder characterized by the accumulation of homocysteine in the body due to a deficiency in the enzyme cystathionine beta-synthase (CBS). This condition can lead to a variety of clinical presentations, signs, symptoms, and patient characteristics that are crucial for diagnosis and management.

Clinical Presentation

Genetic Background

Homocystinuria is primarily inherited in an autosomal recessive manner, meaning that both copies of the gene in each cell have mutations. The most common form is due to a deficiency in the CBS enzyme, which is essential for the metabolism of homocysteine to cystathionine[5][6].

Age of Onset

Symptoms of homocystinuria typically manifest in early childhood, often between the ages of 3 to 10 years, although some cases may present later in life. Early diagnosis is critical to prevent severe complications[8].

Signs and Symptoms

Ocular Manifestations

• Lens Dislocation: One of the hallmark signs of homocystinuria is ectopia lentis, where the lens of the eye is dislocated. This can lead to visual impairment and is often bilateral[8].
• Myopia: Patients frequently exhibit myopia (nearsightedness), which can worsen over time[9].

Skeletal Abnormalities

• Marfanoid Habitus: Individuals may present with features resembling Marfan syndrome, including tall stature, long limbs, and arachnodactyly (long fingers)[9].
• Skeletal Deformities: Other skeletal issues may include scoliosis and chest deformities[8].

Neurological Symptoms

• Developmental Delays: Children with homocystinuria may experience developmental delays and intellectual disability, which can vary in severity[9].
• Seizures: Neurological complications, including seizures, can occur due to elevated homocysteine levels affecting the central nervous system[8].

Vascular Complications

• Thromboembolic Events: Patients are at increased risk for thromboembolic events, such as deep vein thrombosis and pulmonary embolism, due to the prothrombotic nature of elevated homocysteine levels[9][10].
• Atherosclerosis: There is also a higher incidence of premature atherosclerosis, leading to cardiovascular complications[9].

Other Symptoms

• Psychiatric Disorders: Some patients may experience psychiatric symptoms, including anxiety and depression, which can be attributed to both biochemical imbalances and the psychosocial impact of the disorder[8].
• Skin Changes: Rarely, skin manifestations such as hyperpigmentation may occur[9].

Patient Characteristics

Demographics

Homocystinuria affects individuals of all ethnic backgrounds, but the prevalence may vary. It is estimated to occur in approximately 1 in 200,000 to 1 in 300,000 live births globally[1][2].

Family History

A positive family history of homocystinuria or related metabolic disorders is often present, as the condition is inherited in an autosomal recessive pattern. Genetic counseling is recommended for affected families[6][8].

Diagnostic Considerations

Diagnosis is typically confirmed through biochemical testing, which reveals elevated levels of homocysteine and methionine in the blood and urine. Genetic testing can identify mutations in the CBS gene, aiding in definitive diagnosis[7][9].

Conclusion

Homocystinuria (ICD-10 code E72.11) presents a complex clinical picture characterized by ocular, skeletal, neurological, and vascular manifestations. Early recognition and management are essential to mitigate complications and improve the quality of life for affected individuals. Regular monitoring and a multidisciplinary approach involving geneticists, dietitians, and other healthcare professionals are crucial for optimal patient care.

Homocystinuria, classified under the ICD-10-CM code E72.11, is a metabolic disorder characterized by the accumulation of homocysteine in the body due to deficiencies in specific enzymes involved in its metabolism. This condition can lead to various health complications, including cardiovascular issues, skeletal abnormalities, and developmental delays. Below are alternative names and related terms associated with homocystinuria.

Alternative Names for Homocystinuria

1. Cystathionine Beta-Synthase Deficiency: This is the most common form of homocystinuria, resulting from a deficiency in the enzyme cystathionine beta-synthase (CBS) which is crucial for the metabolism of homocysteine.

2. Homocystinuria Type I: This term is often used to refer specifically to the classical form of the disorder, which is linked to CBS deficiency.

3. Homocystinuria due to Methylenetetrahydrofolate Reductase Deficiency: This variant occurs due to a deficiency in the enzyme methylenetetrahydrofolate reductase (MTHFR), which plays a role in the conversion of homocysteine to methionine.

4. Homocystinuria due to Cobalamin Deficiency: This form is associated with vitamin B12 (cobalamin) deficiency, which can affect homocysteine metabolism.

5. Homocystinuria due to Folate Deficiency: Similar to cobalamin deficiency, a lack of folate can also lead to elevated homocysteine levels.

Related Terms

1. Metabolic Disorder: Homocystinuria falls under the broader category of metabolic disorders, specifically those affecting sulfur-bearing amino acids.

2. Amino Acid Metabolism Disorder: This term encompasses conditions like homocystinuria that involve the metabolism of amino acids, particularly those related to sulfur.

3. Cystathioninuria: While not synonymous, this term refers to the presence of cystathionine in the urine, which can be a marker for homocystinuria.

4. Hyperhomocysteinemia: This term describes elevated levels of homocysteine in the blood, which is a hallmark of homocystinuria and can be associated with various health risks.

5. Genetic Metabolic Disorder: Homocystinuria is inherited in an autosomal recessive pattern, making it a genetic metabolic disorder.

6. Skeletal Abnormalities: This term is often used in the context of the physical manifestations of homocystinuria, as patients may exhibit specific skeletal deformities.

Understanding these alternative names and related terms can help in recognizing the various aspects and implications of homocystinuria, particularly in clinical settings where accurate diagnosis and treatment are essential.

Homocystinuria, classified under ICD-10 code E72.11, is a rare genetic disorder characterized by the accumulation of homocysteine in the body due to a deficiency in the enzyme cystathionine beta-synthase (CBS). This condition can lead to various complications, including cardiovascular issues, skeletal abnormalities, and neurological problems. The management of homocystinuria typically involves a combination of dietary modifications, supplementation, and, in some cases, pharmacological interventions. Below is a detailed overview of the standard treatment approaches for this condition.

Dietary Management

Low-Methionine Diet

One of the primary treatment strategies for managing homocystinuria is the implementation of a low-methionine diet. Methionine is an amino acid that, when metabolized, produces homocysteine. By reducing dietary intake of methionine, patients can help lower homocysteine levels. Foods high in methionine, such as meat, fish, eggs, and dairy products, are typically restricted, while fruits, vegetables, and certain grains are encouraged[1].

Supplementation with Cysteine

To counteract the low intake of methionine, patients may be supplemented with cysteine, which can help in the synthesis of proteins and support metabolic processes. This supplementation can also assist in maintaining adequate levels of sulfur-containing amino acids in the body[2].

Vitamin Supplementation

Vitamin B6 (Pyridoxine)

Some patients with homocystinuria respond positively to vitamin B6 supplementation. Pyridoxine is a cofactor for the enzyme involved in the transsulfuration pathway, which can help lower homocysteine levels in those who are responsive to this treatment. Regular monitoring of homocysteine levels is essential to assess the effectiveness of this approach[3].

Vitamin B12 and Folate

Supplementation with vitamin B12 and folate is also recommended, as these vitamins play crucial roles in the metabolism of homocysteine. They help convert homocysteine back into methionine or into other non-toxic compounds, thereby reducing its accumulation in the body[4].

Pharmacological Interventions

Betaine

Betaine is a compound that can be used as a therapeutic agent in homocystinuria. It acts by promoting the remethylation of homocysteine to methionine, thus helping to lower homocysteine levels. Betaine supplementation has been shown to be effective in reducing homocysteine concentrations and improving clinical outcomes in some patients[5].

Monitoring and Follow-Up

Regular monitoring of homocysteine levels is crucial for patients with homocystinuria. This helps in adjusting dietary and supplementation strategies to ensure optimal management of the condition. Additionally, routine assessments for potential complications, such as cardiovascular health and neurological function, are essential to provide comprehensive care[6].

Conclusion

The management of homocystinuria (ICD-10 code E72.11) involves a multifaceted approach that includes dietary modifications, vitamin supplementation, and pharmacological treatments. By implementing these strategies, healthcare providers can help patients manage their condition effectively, reduce the risk of complications, and improve their overall quality of life. Continuous monitoring and individualized treatment plans are vital to achieving the best outcomes for those affected by this metabolic disorder.