Myelodysplastic syndromes (MDS)
MDS (only probes for 5 and 7 done as standard on failed cases (less than 10 analysable cells) please request further probes if required): Monosomy 5/5q deletion Del(5q) 5q31 Deletion 5p15.31 Probe; Monosomy 7/7q deletion Del(7q) 7q22.1/7q31 Deletion Probe; Trisomy for chromosome 8 CEP 8 pectrumOrange/Aqua Direct Labeled Fluorescent DNA Probe Kit; Deletion of chromosome 20q Del(20q) 20q12/20q13.12 Deletion Probe; inv(3)(q21q26) ,t(3;3)(q21;q26); EVI1 Break Apart Rearrangement Probe.
Approximately 40% of confirmed de novo MDS patients have karyotype abnormalities at diagnosis, which helps to confirm the presence of a clonal disorder and aids the distinction between MDS and reactive causes of dysplasia. All the abnormalities most common in MDS including trisomy 8 deletion/monsomy of 5 and 7 can also be founding other myeloid disorders and as such are not specific for MDS. However, some chromosome abnormalities indicate more aggressive disease and therefore have prognostic value.
The Cytogenetic karyotype is included in the IPSS scoring system in adult MDS (Greenberg et al 1997) and the following prognostic groups are recognised: Good Prognosis: Normal karyotype, -Y, del 5q, del 20q (the latter two as sole abnormalities); Intermediate prognosis: Trisomy 8 and all others; Poor prognosis: Complex karyotype (>3 abnormalities), chromosome 7 abnormalities.
For all failed cases with a confirmed or suspected diagnosis of MDS, FISH for chromosome 5 and 7 abnormalities is recommended.
All samples must be delivered to the laboratory within 24 hours of collection.
Blood Sciences Laboratory
Ground Floor Bessemer Wing
King’s College Hospital
London SE5 9RS
Last updated: 03/07/2017