Dermatologic Manifestations of Homocystinuria Treatment & Management

Updated: May 17, 2022
  • 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. [66, 67, 68]

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. [69, 70]

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. [71] 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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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. Liu et al 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. [72]

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