1.5Q long arm deletion is the most common abnormal in AML and MDS. The Abnormalities on chromosome No. 5 is accounted for more than up to 40% of treatment-related MDS.
2.The internal deletion of 5Q (5Q31-Q33) occurs in 10-15% of MDS patients , The result has a good prognosis.
3.5Q deletion syndrome is an independent molecular type newly added by WHO in 2000. The majority of female patients have a better prognosis.