Only about 5,800 of these are believed to be true functional genes.

Thereby the other functional gene does not produce enough of a gene-product to have the expected function, resulting in an abnormal disease state.

Genome size is of little relevance when considering the number of functional genes in eukaryotic species.

Enter gene therapy, which works by replacing flawed genes with fully functional genes.

Even functional mitochondrial genes accumulate mutations faster and more freely.

In order to transfer a functional gene into the target cell, viral or non-viral vectors can be employed.

However, many people remain healthy with such a loss, because there still is one functional gene left on the other chromosome of the chromosome pair.

Cells lacking the extrachromosomal array also lack the functional gene of interest.

Less than half of the genome contains functional genes.

The mouse Ear family has at least 13 members, 11 functional genes and 2 pseudogenes [ 29].