Reading is not a biological trait that can be inherited.
Written language is only a few thousands years old, and the expectation that all children should become literate  is a very recent cultural deelopment. This is far too short a period for such a complex behaviour to evolve genetically. No one is born with a “reading gene” or with dyslexia.

What can be inherited are underlying skills, such as the ability to hear and manipulate sounds in words, or general aptitudes like balance and visuomotor integration. These are natural brain functions. Just as no one inherits the act of skateboarding but may inherit the balance and coordination needed to do it with ease, no one inherits the act of reading. 

When difficulties occur, they are the result of how these natural variations in aptitude interact with instruction, not because of an inherited disorder. Some will find it easy, others very difficult. Some will need very little instruction, while for others the instruction they receive will affect them for life.

The window for reading with ease is small. This is known as the dyslexia paradox. If children are struggling by the end of Year One, they are being set up for a lifetime of literacy difficulties.

This is why we screen for the underlying skills that are needed to read. And it is why we view children who struggle to read and spell as instructional casualties, not as children with a genetic disorder or learning disability. Our focus is therefore on understanding the instruction each child needs before they start learning to read and spell. Prevention is far more effective than remediation. Remediation strategies and programmes are generally poor, and very few children who need them ever become avid readers.