<prompt> Which is the most common cytogenetic abnormality in adult myelodysplastic syndrome MDS -Trisomy 820q?5q?Monosmy 7  <response>: Answer is C 5q- Monosomy 7 is by far the most common cytogenetic abnormality in children pediatric MDS whereas 5q- is observed most frequent!, in adults - Myelodysplastic Syndromes by John Bennett 2002300 Cytogenetic Abnormalities in MDS: Facts to Remember Monosomy 7 is the most frequent cytogenetic abnormality in children.Q Deletion 5q 5q is the most frequent cytogenetic abnormality in adults Q. Trisomy 8 is the most frequent tri.somyQ. Differences between Myelodysplastic Syndromes in children and Adults Myelodysplastic Syndromes 2002300; Childhood Leukemias 2549 Feature Children Adults Frequency Less common More common Presence of sideroblasts Uncommon 2 More common ,--25 Cytogenetic Abervations -77q- Most common r,30 Less common ,-40 -55q- Uncommon --L-1-2 Most common z20 