The other user was right about karma, although not necessarily of the person who was born with the condition. Karma is a really broad and sensitive subject that shouldn't be brought up lightly.
Trying to find reasons for it in astrology, however, might not be very advisable. Astrology is mainly used for identification of a person's energy, traits, tendencies, etc. I'm not saying it's not possible to see it in one's birth chart, I'm just saying it's better to use astrology to focus on your personal present, not to confine someone to sentences or judgments for situations and events from their past or future.