The 5q‐ chromosome abnormality in haematological disorders: |a collaborative study of 34 cases from the Netheralands

Summary. Clinical, haematological and cytogenetic data of all patients with an acquired 5q ‐ abnormality, diagnosed in four cytogenetic laboratories, were studied. The 5q‐ arose de novo in 24 patients, while 10 patients exhibited it after radiation and/or chemotherapy. Sixteen cases with a dysmyelopoietic syndrome (DMPS) and one case with acute nonlymphocytic leukaemia (ANLL) had no chromosome abnormalities other than 5q‐ . All nine patients with refractory anaemia (RA) belonging to the de novo group had a normal cell line. So far none of them has transformed to acute leukaemia, while three patients with refractory anaemia with excess of blasts (RAEB), pure red cell aplasia (PRCA) and acquired idiopathic sideroblastic anaemia (AISA), having the 5q‐ in 100% of the cells showed such a transformation. The second group consisted of nine patients with a 5q‐ and additional chromosome abnormalities: three of them died of progression of the disease, while four died of unrelated causes. Eight out of nine patients with a 5q‐ and acute leukaemia, either de novo (five) or secondary (four) to radiation and/or chemotherapy, had additional chromosome abnormalities. Among the changes (partial) monosomy of chromosome 7 was most frequently found. The median survival time of the group of patients with an isolated 5q‐ in the presence of a normal cell line was significantly longer than that of patients with additional chromosomal changes with or without acute leukaemia. All patients with an isolated 5q‐ abnormality showed the previously reported megakaryocytic abnormalities (small mono‐ or bilobulated). In most of the other patients these megakaryocytic abnormalities were also found, whereas others were definitely normal in this respect. A striking and unexplained preponderance of females (1 2 out of 16) was found in the group with an isolated 5q‐ anomaly. All deletions studied with banding techniques appeared to be interstitial but the breakpoints were variable. The shortest region of overlap is near band 5q22. Copyright © 1982, Wiley Blackwell. All rights reserved