We do not allow to search with ['] or ["] in the string.
For traits such as [Crohn's disease], search using [Crohn] will lead to the desired results.
A list of traits with special letters in their names are as below:
Alzheimer's disease
Autism, Asperger's or autistic spectrum disorder
Bell's palsy
Crohn's disease
Father's age at death
Mother's age at death
Hodgkin's disease or non-Hodgkin's disease
Parkinson's disease
Crohn's Disease