What you should ask is how to explain congenital diseases with Buddhism.
The following views are personal views and are for reference only.
First of all, from the cognitive point of view, the so-called disease, luck, bad luck and so on. Everything is fate, there is no right or wrong. We are divided into good and evil according to our personal preferences and gains and losses. This is the self, which is a very strange and interesting question. The inner self is thinking about when, in what form and in what meaning this "I" exists. Scientifically speaking, it's like: the brain releases a message telling me that the brain is the most important organ, and then the brain accepts this message and judges that it is correct.
From the perspective of perception: compared with a healthy body, natural disability is an misfortune, and this unfortunate view is relative, relative to a healthy body. Others think that the disease is bad, that is, the brain accepts the message that "others think the disease is bad", and then many people say that "I" judged this information correctly, so I think that "the disease is bad". With this knowledge, anger will arise. Why is God unfair? Waiting for the idea to appear. If a person, no one tells him the quality of this information, but tells him in a smarter way. People's six senses (sight, hearing, touch, smell, taste and perception (subconscious)) are actually what we call healthy people, and we have all lost a lot. Only when we lack knowledge can we feel normal. He won't give birth to other ideas, which is also a result.
You can't type a lot here. To make a long story short, life is so beautiful, life paths are varied, Prajna wisdom is like the sea, and the long road to practice is Xiu Yuan and Amitabha ~