Suggestion: Apert Syndrome is a genetic disorder that causes craniosynostosis ( premature fusion of bones in the head which cause the head and face to look misshapen), fusing of the toes, bulging eyes, vision problems, and ear infections (These are not all the symptoms, it will take too long to write every single syndrome.)
I think should be a visible at birth mutation since this condition is noticeable at birth and not a lethal since people with this condition have a normal life expectancy.
Sources: https://medlineplus.gov/genetics/condition/apert-syndrome/#frequency

https://www.dellchildrens.net/services-and-programs/craniofacial-care/craniofacial-program/craniofacial-conditions-treated/apert-syndrome/

https://rarediseases.org/rare-diseases/apert-syndrome/#:~:text=Apert%20syndrome%20is%20a%20rare,of%20the%20skull%20close%20prematurely.

https://www.dellchildrens.net/services-and-programs/craniofacial-care/craniofacial-program/craniofacial-conditions-treated/apert-syndrome/

I'm open to constructive criticism and tell me if I got anything wrong or miss something about Apert Syndrome.