Conversation so far:
What year was Irving Thalberg born?
Thalberg was born in 1899.
Who were Irving Thalberg's parents?
Thalberg was born in Brooklyn, to German Jewish immigrant parents, William and Henrietta.
Did Irving Thalberg have any siblings?
Irving had a sister named Sylvia.
Did being diagnosed with blue baby syndrome“ impact Irving Thalberg at all in life?
During his high school years in Brooklyn, he began having attacks of chest pains, dizziness and fatigue. This affected his ability to study.
Where did Irving Thalberg go to school?
Thalberg went to high school in Brooklyn.

Question: What caused his illness in high school?
Self-contained rewrite: What caused Irving Thalberg's illness in high school?