For a child to be considered a permanently and totally disabled child, what conditions must be met according to the definition?

For a child to be considered permanently and totally disabled, it is essential that they cannot engage in any substantial gainful activity. This criterion is a fundamental aspect of defining disability, as it focuses on the child's ability to work and perform tasks that are typically expected of someone their age. If a child is unable to engage in such activities due to a physical or mental condition, they meet an important part of the definition of being permanently and totally disabled.

The other conditions mentioned—like the duration of the condition or parental disability—are not standard requirements for defining a child's permanent and total disability. While age could be relevant in determining eligibility for certain programs, it does not directly relate to the assessment of disability itself. Thus, the main qualifying factor is the child's inability to engage in substantial gainful activity, which is critical in evaluating their disability status.