G6PD deficiency is the most common human enzyme defect.

G6PD deficiency is the most common human enzyme defect, being present in more than 400 million people worldwide.

Symptom severity is predictably correlated with the severity of the enzyme defect.

There appear to be several different types of genetically determined enzyme defects that can cause Leigh's disease.

This variation is caused not by compound heterozygosity, but rather by the fact that several different enzyme defects can cause the disease.

"It's an enzyme defect," I explained as I sat back down.

He described the nature of recessive inheritance of most enzyme defects.

The medical condition associated with this enzyme defect is called hereditary coproporphyria.

In general, enzyme defects are inherited - passed on from parents to children in the form of an abnormal gene.

So one might expect chemical sensitivity to run in families, if enzyme defects are a common cause of the problem.