Myelodysplastic syndromes (MDS)
Description:
Tests available: Karytyping and FISH
FISH:
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.
FISH:
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.
Clinical details:
MDS is a neoplastic disorder characterised by the simultaneous proliferation and apoptosis of haematopoietic cells. In the majority of cases MDS can be classified using the blast percentage of all marrow nucleated cells. At present there are seven WHO categories, which will be named briefly but not discussed in detail. Refractory Anaemia (RA), Refractory anaemia with ringed sideroblasts (RARS), Refractory anaemia with excess blasts (RAEB-1), Refractory anaemia with excess blasts (RAEB-2)’ Myelodysplastic syndrome-unclassified (MDS-U), MDS associated with isolated del5(q), Myelodysplastic syndrome unclassifiable, Childhood myelodysplastic syndrome.
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.
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.
Department:
Location:
Sample type and Volume required:
Bone Marrow Aspirate - first draw
Turnaround time:
Please refer to Cytogenetics User Guide
Special sample instructions:
All samples must be delivered to the laboratory within 24 hours of collection.
Contacts:
SE-HMDS Department at King's College Hospital
020 3299 9000 ext 32414
c/o Central Specimen Reception
Blood Sciences Laboratory
Ground Floor Bessemer Wing
King’s College Hospital
Denmark Hill
London SE5 9RS
Mon-Fri, 9.00am-5.30pm
Blood Sciences Laboratory
Ground Floor Bessemer Wing
King’s College Hospital
Denmark Hill
London SE5 9RS
Mon-Fri, 9.00am-5.30pm
Laboratory:
Last updated: 03/07/2017
