Low blood counts can be attributed to several different medical conditions. Distinguishing myelodysplastic syndromes (MDS) from other bone marrow failure disorders can be challenging; however, it is important in the determination of prognosis and treatment. The use of molecular markers has become increasingly useful in making this distinction.
- After benign causes of low blood counts, such as vitamin deficiencies, are excluded, the first step in a suspected bone marrow failure disorder is to examine the peripheral blood smear and perform a bone marrow aspirate and biopsy. A thorough physical examination, family history, and review of old blood counts, medications, and exposures, are all part of the diagnostic workup.
- Certain chromosomal abnormalities can help to distinguish MDS from other bone marrow failure disorders, such as del (5q), monosomy 7, inversion 3, del (Y), 20q, and trisomy 8 among others.
- The diagnosis of MDS may be more difficult in patients with no chromosomal abnormalities and non-specific bone marrows that do not have clear evidence of dysplasia. Since these patients often have a milder decrease in their blood counts and no increase in immature cells, they can be followed by routine blood tests and a repeat bone marrow examination if counts worsen or in 6+ months.
- Elevations in CD34 count in the bone marrow can help to distinguish MDS from other bone marrow failure disorders.
- Other diseases that may manifest with low blood counts include aplastic anemia, large granular leukemia, paroxysmal nocturnal hemoglobinuria, inherited bone marrow failure syndromes, myeloproliferative neoplasms, and pure red cell aplasia.
- Single-nucleotide polymorphism array karyotyping (SNP-As) and molecular genetic testing are now commonly used in specialized centers to further diagnose and risk stratify patients with MDS. More than 30 recurrent MDS-associated mutations have been identified, and several of these mutations have prognostic implications. Some of these mutations can also help to distinguish MDS from other bone marrow failure syndromes.
- MDS can occasionally be difficult to distinguish from other bone marrow failure syndromes.
- In addition to routine bone marrow testing, newer molecular and genomic testing can aid in diagnosis and prognosis and ultimately treatment strategies.