| dc.contributor | Picos-Cárdenas, V.J., Universidad de Guadalajara and División de Genética, Centro de Investigación Biomédica de Occidente, Instituto Mexicano del Seguro Social, Guadalajara, Jalisco, Mexico; Meza-Espinoza, J.P., Universidad de Guadalajara and División de Genética, Centro de Investigación Biomédica de Occidente, Instituto Mexicano del Seguro Social, Guadalajara, Jalisco, Mexico; Gutiérrez-Angulo, M., Universidad de Guadalajara and División de Genética, Centro de Investigación Biomédica de Occidente, Instituto Mexicano del Seguro Social, Guadalajara, Jalisco, Mexico; Esparza-Flores, M.A., Departamento de Hematología, Hospital de Pediatría, Instituto Mexicano del Seguro Social, Guadalajara, Jalisco, Mexico; Ayala-Madrigal, M.L., Departamento de Fisiología, CUCS, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico; Hansmann, I., Institut fuer Humangenetik und Medizinishe Biologie, Universitaet Halle-Wittenberg, HalleSaale, Germany; González, G.J.R., Universidad de Guadalajara and División de Genética, Centro de Investigación Biomédica de Occidente, Instituto Mexicano del Seguro Social, Guadalajara, Jalisco, Mexico | |
| dc.description.abstract | We report a boy with Down syndrome and leukemia who acquired uniparental isodisomy of chromosome 7q as a secondary chromosomal change during recurrence of the disease. His karyotype before therapy was 46,XY,der(1)t(1;1)(p36;q32),-7,+21c[17]/46,idem,del(9)(p22)[10], whereas at recurrence it was 46,XY,der(1)t(1;1)(p36;q32,-7,der(7)(qter→p22∼pter::q10→qter), del(9)(p22),+21c[13]/47,XY,+21c[2]. By using polymerase chain reaction amplification of D7S493 and D7S527 markers, we identified the loss of the maternal chromosome 7 with a consequent paternal isodisomy in the clone with dup7q. This rearrangement could be implicated in the progression of the disease by causing (1) nullisomy for a gene or genes located on 7p22→pter, (2) functional double doses of exclusively paternal expressed genes, and (3) restoration of the effects produced by haploinsufficiency of biparental expressed genes. © 2002 Elsevier Science Inc. All rights reserved. | |
