Dermatologic Manifestations of Homocystinuria Treatment & Management

Updated: Jun 21, 2018
  • Author: Janette Baloghova, MD, PhD; Chief Editor: Dirk M Elston, MD  more...
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Treatment

Medical Care

The diagnosis should be established as early as possible. Neonates in whom homocystinuria is diagnosed have had a benign course when they are fed on methionine-restricted cysteine-supplemented diets. Cysteine can be supplemented to a maximum of 500 mg/d.

The administration of pyridoxine in high doses (300-600 mg/d) is effective in some patients.

Other possible treatments include the use of folic acid (in pharmacologic doses), betaine (3-methylglycine decreases serum concentrations of homocysteine), or cyanocobalamin, as well as symptomatic supportive measures.

Homocysteine Reduction Formula, a special nutritional supplement created by Brimhall, can also lower homocysteine levels.

In patients with hypothyroidism, treatment with L-thyroxine can normalize homocysteine levels.

Betaine improves metabolic control in B6-nonresponsive patients with homocystinuria after optimum dietary control. [64, 65, 66]

Betaine therapy can precipitate cerebral edema, although the exact mechanism is uncertain. Betaine does raise the methionine level, and cerebral edema can occur when plasma methionine values exceed 1000 µmol/L. Methionine levels must be monitored in patients with cystathionine beta-synthase deficiency who are on betaine; consider betaine as an adjunct, not an alternative, to dietary control. [67, 68]

However, even when patients' serum betaine concentrations are increased by supplementation, serum homocysteine concentrations are often not lowered to the reference range. Following a low-methionine diet that keeps serum methionine within the reference range may be necessary when treating patients with homocystinuria due to cystathionine beta-synthase deficiency when betaine is administered.

Conventional treatment of cystathionine beta-synthase deficiency by diet and pyridoxine/betaine normalizes many, but not all, metabolic abnormalities associated with cystathionine beta-synthase deficiency. [69] The finding of low plasma serine concentrations in patients with untreated cystathionine beta-synthase deficiency may merit further exploration because supplementation with serine might be a novel and safe component of treatment of homocystinuria.

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Surgical Care

Surgical treatment should be considered, especially in patients with pupillary-block glaucoma or in those with recurrent lens dislocation into the anterior chamber. Other ophthalmologic or orthopedic disorders should be corrected.

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Consultations

An ophthalmologist should be consulted for the treatment of repeated lens dislocation, acute pupillary-block glaucoma, and other ophthalmologic disorders.

An orthopedist should be consulted to correct orthopedic disorders.

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Diet

Patients must maintain a diet with limited amounts of protein (1 g/kg) and amino acid mixtures. The diet must be free of protein hydrolysate.

Patients in whom the disease does not respond to pyridoxine supplements must be treated with dietary reductions in methionine and with cysteine supplementation.

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Long-Term Monitoring

There are very few reports of pregnancies in females with homocystinuria. Pregnancy in an affected female is associated with an increased risk of complications, miscarriage, a definite risk of a thromboembolic event. Chinese authors report a case of a 23-year-old woman who had late-onset cblC, which presented at age 15 years. After long-term treatment she completely recovered. Protein intake was not restricted before or during pregnancy. She underwent a successful pregnancy and delivery of a healthy baby at term. [70]

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