But 55 percent of all white people carry a version of the gene that yields a defective enzyme that cannot break down chemicals efficiently.

This defective enzyme ultimately results in the accumulation of certain complex carbohydrates (mucopolysaccharides) and fatty substances (mucolipids) in various tissues of the body.

So women who inherited that defective enzyme and did not get large amounts of folic acid would be exposing their fetuses to the dangerous substance homocysteine.

Furthermore, chaperone therapy, a technique used to stabilize the defective enzymes produced by patients, is being examined for certain of these disorders.

In the case of under-expression or expression of a defective enzyme, an active form of the enzyme is introduced in the body to compensate for the deficit.

Genetic GSD is caused by any inborn error of metabolism (genetically defective enzymes) involved in these processes.

In addition, the defective lysosomal enzymes normally found only within lysosomes are instead found in high concentrations in the blood.

The defective enzyme in Canavan disease, aspartoacylase, converts N-acetylaspartate into aspartate and acetate.

However, several theories are in place with regards to the nature of this disease including the presence of a genetically defective enzyme involving a neuroectodermal tissue constituent.

The disease, affecting one in 14,000 babies, or about 300 each year, involves a missing or defective enzyme that metabolizes the amino acid phenylalanine.