What are some common chromosome abnormalities?

See below: Turner's syndrome, down's syndrome, trisomy 18 are some of the more commonly diagnosed chromosome problems.

Down Syndrome: Trisomies (3 instead of 2 of a certain chromosome) are most common. Down is caused by an extra copy of chromosome 21. Patients usually have lower iq, shortened lifespans and specific facial and anatomic features. Edwards syndrome involves an extra copy of 18. The most common in utero is 16, though spontaneous miscarriage rates are very high. Patau syndrome (extra 13) also has a high mortality.