The Principles of Clinical Cytogenetics - Extra Materials - Springer

378 Rizwan Naeem
Refractory Anemia
Table 4
Recurrent Primary Chromosome Aberrations
in Myelodysplastic Syndromes
del(1)(p22) +9
t(1;3)(p36;q21) t(9;11)(p22;q23)
der(1;7)(q10;p10) t(9;22)(q34;q11.2)
t(2;11)(p21–22;q23) +11
t(3;21)(q26;q22) del(11q) c
3q26 abnormalitiesa del(12)(p11–13)
–5 del(13q) d
del(5q)a 16q22 abnormalities
t(5;12)(q33;p13) i(17q)
+6 +19
t(6;9)(p23;q34) del(20q) e
–7 +21
del(7q) –X
+8 –Y
t(8;21)(q22;q22)
a Includes inv(3)(q21q26), t(3;3)(q21;q26), ins(3;3)(q21q26).
b del(5)(q13q33) observed in “5q–” syndrome.
c Includes breakpoints at 11q14 and 11q23.
d Includes breakpoints 13q11.2-22.
e Includes breakpoints 20q11.2-13.
Cytogenetic abnormalities can be observed in up to 25% of cases of refractory anemia (RA).
Several different acquired clonal chromosomal abnormalities have been identified, and although useful
for helping to establish a diagnosis of refractory anemia and for acting as a marker to follow a
patient’s progress, they are not specific. These abnormalities include deletion of chromosome 20,
trisomy of chromosome 8, and abnormalities of chromosome 5 and/or 7 (see Fig. 2z,aa,c,d,h,i,j,k).
Refractory Anemia with Ringed Sideroblasts
Clonal chromosomal abnormalities are seen in fewer than 10% of cases of refractory anemia with
ringed sideroblasts (RARS). If clonal cytogenetic abnormalities develop during the course of the
disease, the case should be evaluated and appropriately reclassified, as this is evidence of another
form of MDS or development of AML.
Refractory Cytopenia with Multilineage Dysplasia
The clonal chromosomal abnormalities seen in refractory cytopenia with multilineage dysplasia
(RCMD) include trisomy 8, monosomy 7, deletion of 7q, monosomy 5, deletion of 5q, and deletion
of 20q (see Fig. 2c,d,h,i,j,k,z,aa). Complex karyotypes might be found in up to 50% of patients with
RCMD and RCMD with ringed sideroblasts (RCMD-RS).
Refractory Anemia with Excess of Blasts
About 30–50% of cases of refractory anemia with excess of blasts (RAEB) have clonal cytogenetic
abnormalities. These include trisomy 8, deletion of 5q, monosomy 5, monosomy 7, deletion
of 7q, and deletion of 20q (see Fig. 2c,d,h,i,j,k,z,aa). Complex karyotypes might also be
observed in small percentage of cases. The number of blasts in bone marrow and blood is usually
less than 5% (63).