Chromosomal Disorders What are the most common chromosomal disorders? There are numerous chromosomal disorders. The actual disorder arises from some type of malformation during mitosis. There is usually an extra chromosome or a part missing of a chromosome. Trisomy 13, Trisomy 18, and Trisomy 21 are the most common chromosomal disorders. Trisomy 13 Syndrome is a chromosomal disorder resulting in a syndrome characterized by specific (midline) dysmorphic features and organ malformations. Trisomy 13 occurs in one out of every 4,000 to 10,000 …showed first 75 words of 838 total…

…showed last 75 words of 838 total…pregnancy is possible with a 50% chance of Trisomy. In conclusion, Trisomy 13, Trisomy 18 and Trisomy 21 are the most common chromosomal disorders. Trisomy 13 occurs in one of every 4,000 to 10,000 births. Trisomy 18 occurs in one of every 8,000 births. Trisomy 21 occurs in an amazing one of every 800 births. The one contributing factor seen present in all of these syndromes is advanced maternal age. Other than that and genetics there is really nothing one can do to prevent these abnormalities.