Dyslexia or autism. For my research?

My brother is 14 years old and has some challenges that affect his daily activities. He cannot smell anything because he lacks a sense of smell, and he struggles with cycling as he falls down frequently and cannot balance the cycle for even a second. Moreover, he has difficulty playing cricket, despite trying his best to catch the ball, he often misses it. I suspect that he may have dyslexia or autism, and I'm keen to understand which brain functions are responsible for his difficulties. Could you suggest some keywords for my research? I'm aware that multiple brain functions can contribute to these conditions, such as "motor function," "sensory processing," or "executive function. I want to learn more about this