Identical twins, who have inherited the same affected gene, typically have differing ages of onset and symptoms.

Below is one of the affected genes and the disease that arises from its mutation.

As social scientists often work with many variables, determining the number of affected genes also poses methodological challenges.

First, the affected gene in most cases is that for a transport protein (StAR) rather than a steroidogenic enzyme.

If the parents do not have the affected gene, the recurrence risk appears to be low.

The affected genes are divided into two broad categories.

The affected gene on the X chromosome codes for the gp91 protein p91-PHOX (p is the weight of the protein in kDa; the g means glycoprotein).

In order to inherit it, both of the parents of an individual must carry an affected gene.

Defined genetic backgrounds allow researchers to identify and locate affected genes in mutant individuals with greater efficiency.