Article
Paternal isodisomy 7q secondary to monosomy 7 at recurrence in a Down syndrome child with acute myelogenous leukemia.
Short communication
Autor
Picos Cárdenas, V.J.
Meza Espinoza, Juan Pablo
Gutiérrez Angulo, Melva
Esparza Flores, M.A.
Ayala Madrigal, María de la Luz
Hansmann, I.
González, G.J.R.
Institución
Resumen
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. Universidad de Guadalajara and División de Genética, Centro de Investigación Biomédica de Occidente, Centro Médico Nacional de Occidente, Instituto Mexicano del Seguro Social, Guadalajara, Jalisco, México
Departamento de Hematología, Hospital de Pediatría, Centro Médico Nacional de Occidente, Instituto Mexicano del Seguro Social, Guadalajara, Jalisco, México
Departamento de Fisiología, CUCS, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico
Institut fuer Humangenetik und Medizinishe Biologie, Universitaet Halle-Wittenberg, Halle\Saale, Germany