What Is Hyperhomocysteinemia?

Hyperhomocysteinemia, also known as homocysteineuria, is a rare autosomal recessive genetic disease that is caused by the lack or deficiency of cystathionine beta synthase, causing homocysteine to accumulate in the blood. Disease of excess homocysteine in urine. The disease has the following clinical features: developmental delay, osteoporosis, eye abnormalities, equine-like syndrome manifestations, thromboembolic disease, and premature severe atherosclerosis. According to statistics, the global incidence of homocysteineuria is 1 / 344,000.

Basic Information

nickname

Homocysteineuria

Visiting department

Cardiology

Common causes

Methionine metabolic disorder

Common symptoms

Cardiovascular disease

Contagious

no

Causes of hyperhomocysteinemia

Hyperhomocysteinemia is an autosomal recessive disease. The gene is located on chromosome 21 and there are five different types of biochemical defects: cystathionine-deficiency enzyme-deficiency and cyanocobalamin-reductase-deficiency. , Methyltetrahydrofolate-homocysteine methyltransferase deficiency, 5,10-N-methylenetetrahydrofolate reductase deficiency, and mixed enzyme deficiency.

Clinical manifestations of hyperhomocysteinemia

Eye abnormality

Patients may have abnormal eye symptoms such as lens ectopic, optic nerve atrophy, retinal detachment, myopia, cataract, familial exudative vitreoretinopathy-like manifestations, and so on.

Cardiovascular disease

Patients may develop extensive coronary atherosclerosis, which can result in death from thrombosis and coronary occlusion.

3. Skeletal muscle abnormalities

Patients may have equine-like syndrome manifestations, such as spider-like slender fingers (toes), weak muscles, fragile and tall individuals, slender limbs, scoliosis and kyphosis, etc., and may have pale yellow hair, scarce and qualitative Brittle, flushing complexion with reticular plaques, etc., some patients showed high arched feet, knee valgus or chicken breasts.

4. Mild mental decline and psychological and mental disorders

Patients may have psychosocial symptoms such as mental retardation, seizures, hemiplegia and aphasia, and mental retardation.

Hyperhomocysteinemia test

Laboratory inspection

Blood homocysteine detection: Plasma homocysteine levels> 15 mol / L.

2. Genetic testing

In severe cases, there may be deletions of the MTHFR gene and methionine synthetase.

Diagnosis of hyperhomocysteinemia

The disease is based on typical symptoms, such as skeletal abnormalities, ocular symptoms, and mental decline. Laboratory tests can increase the level of plasma homocysteine and methionine for preliminary diagnosis. Combining genetic testing can confirm the diagnosis. The normal fasting plasma homocysteine level is 5 to 15 mol / L. If the homocysteine level is> 15 mol / L, it can be diagnosed as hyperhomocysteinemia.

Differential diagnosis of hyperhomocysteinemia

This disease needs to be distinguished from diseases such as hypermethionineemia, methionine malabsorption syndrome, equine syndrome, cystathionineuria, and methylmalonic aciduria.

Treatment of hyperhomocysteinemia

At present, there are no mature measures for the treatment of this disease. They mainly include diet control and drug treatment to reduce the accumulation of homocysteine in the blood and prevent systemic complications such as nerve and cardiovascular.

Diet control

Fruits, vegetables, low-fat dairy products, low-saturated fat, and low-fat diets can reduce fasting serum homocysteine levels. Limit animal protein intake.

2. Drug treatment

For hyperhomocysteinemia caused by environmental nutritional factors, vitamin B ₆ , vitamin B ₁₂ or folic acid can be added.

Prognosis of hyperhomocysteinemia

The prognosis of this disease is poor, and it is closely related to the occurrence of thrombosis, lens dislocation, extensive atherosclerosis, and cardiovascular and cerebrovascular accidents in patients with hyperhomocysteinemia.

Hyperhomocysteinemia prevention

Because the disease is a genetic disease, those with a family history of hyperhomocysteinemia should do genetic counseling and prenatal diagnosis, which will help you to have a good birth and high birth.