Homocystinuria, also known as Cystathionine beta synthase
deficiency, is inherited disorder of the metabolism of the amino
acid methionine. It is inherited an autosomal recessive trait, which
means the child is to inherit the defective gene from both parents.
This defect leads to a multisystemic disorder of the connective
tissue, muscles, CNS, and cardiovascular system.
Homocystinuria represents a group of hereditary metabolic
disorders characterized by an accumulation of homocysteine in the
serum and an increased excretion of homocysteine in the urine.
Infants appear to be normals and early symptoms, if any are present,
- A family history of homocystinuria
- Flush across the cheeks
- Tall, thin build
- Long limbs
- High-arched feet (pes cavus)
- Knock-knees (genu valgum)
- Pectus excavatum
- Pectus carinatum
- Mental retardation
- Psychiatric disease
The life expectancy of patients with homocystinuria is reduced.
It is known that before the age of 30, almost one fourth of patients
die as a result of thrombotic complications(e.g. heart attack).
No specific cure has been discovered for homocystinuria. However,
many people are treated to high doses of vitamin B6(also known as
pyridoxine). Slightly less than 50% respond to this treatment and
are needed to intake supplemental vitamin B6 for the rest of their
lives. Those that do not respond require a low methionine diet, and
most will need treatment with trimethylglycine. A normal dose of
folic acid supplement and occasionally added cysteinein the diet is
Low-protein food is recommended for these disorder requires food
products which are low in particular types of amino-acid (i.e.
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