title: Inversion of chromosome 7q22 and q36 as a sole abnormality presenting in myelodysplastic syndrome: a case report.
abstract: BACKGROUND
  Deletions of chromosome 7 are often detected in myelodysplastic syndrome. The most commonly deleted segments are clustered at band 7q22. A critical gene is therefore suggested to be located in this region. We report a patient with myelodysplastic syndrome whose marrow cells carried an inversion of 7q22 and q36 as a sole karyotypic abnormality. How this extremely rare chromosomal aberration contributes to the pathogenesis of myelodysplastic syndrome should be clarified by accumulating clinical data of such cases.
  
  
  METHODS
  A 74-year-old Japanese man presented with pancytopenia incidentally detected by routine medical check-up. His complete blood cell counts revealed that his white blood cells had decreased to 2100/mm3, neutrophils 940/mm3, red blood cells 320×104/mm3, hemoglobin 11.1g/dL, hematocrit 33.1%, and platelets 12.6×104/mm3. Bone marrow examination showed normal cellularity with nucleated cells of 9.4×104/mm3. The proportion of blasts was 4%. A morphological examination showed only basophilic stippling of erythroblasts which was seen as dysplasia. According to World Health Organization classification, the diagnosis was myelodysplastic syndrome-u. Karyotypic analysis showed 46,XY,inv(7)(q22q36) in all of 20 metaphases examined. Additional analysis revealed the karyotype of his lymphocytes was 46,XY. He is asymptomatic and cytopenia has slowly progressed.
  
  
  CONCLUSIONS
  To the best of our knowledge, this karyotype from a clinical sample of de novo malignancies has never been documented although the identical karyotype from secondary myelodysplastic syndrome was reported. Despite the extremely low frequency, inversion of 7q22 appears to play a crucial role for myelodysplastic syndrome in this patient.
authors.affiliation: Department of Hematology, Japanese Red Cross Kyoto Daiichi Hospital, 15-749 Honmachi, Higashiyama-ward, Kyoto 605-0981, Japan. hiroto-kaneko@kyoto1-jrc.org.
authors.forename: Hiroto
authors.initials: H
authors.lastname: Kaneko
authors.forename: Kazuho
authors.initials: K
authors.lastname: Shimura
authors.forename: Saeko
authors.initials: S
authors.lastname: Kuwahara
authors.forename: Muneo
authors.initials: M
authors.lastname: Ohshiro
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Tsutsumi
authors.forename: Toshiki
authors.initials: T
authors.lastname: Iwai
authors.forename: Shigeo
authors.initials: S
authors.lastname: Horiike
authors.forename: Shouhei
authors.initials: S
authors.lastname: Yokota
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ohkawara
authors.forename: Masafumi
authors.initials: M
authors.lastname: Taniwaki
mesh_terms: D000368:Aged; D007446:Chromosome Inversion / Q000235:genetics*; D002897:Chromosomes, Human, Pair 7 / Q000235:genetics*; D006801:Humans; D007621:Karyotyping; D008297:Male; D009190:Myelodysplastic Syndromes / Q000235:genetics*
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