MDS-IB is broken down into two groups based on the number of blasts in the bone marrow and peripheral blood:
| Criteria | MDS-IB1 | MDS-IB2 |
| Bone marrow aspirate blast count (count >500 cells) | 5–9% | 10–19% |
| Peripheral smear blast count (count >200 cells) | 2–4% | 5–19% |
| Auer Rods | absent | might be present |
Our patient falls into the MDS-IB2 category. Over half of all MDS-IB patients show cytogenetic abnormalities. The most common include del(5q), -7, del(7q) (our patient), +8, and del(20q). Slightly less than 50% do not have cytogenetic changes but rather various point mutations. Also, cytogenetic abnormalities and point mutations can be found in the same patient.
