Down syndrome with low hypodiploidy in precursor B-cell acute lymphoblastic leukemia.
We describe the rare finding of a 33-month-old child neonatally diagnosed with Down syndrome, who presented with pre-B acute lymphoblastic leukemia (ALL) with a pretreatment bone marrow karyotype in which a low hypodiploid cell line (38 chromosomes) was identified in 17/19 cells studied. The abnormal cell line retained the extra constitutional chromosome 21. Hypodiploidy (loss of one or more chromosomes) is seen in approximately 5% of all childhood pre-B ALL cases and in approximately 2.2% cases of individuals with a constitutional trisomy 21. Low hypodiploidy, associated with a high risk of relapse, is rare in pediatric ALL cases in the general population, and, to our knowledge, is previously unreported in patients with trisomy 21.
Morrissette
Jennifer J D
JJ
Department of Pathology and Laboratory Medicine, Section of Cytogenetics, Drexel University College of Medicine, St. Christopher's Hospital for Children, Philadelphia, PA 19134, USA. Jennifer.Morrissette@tenethealth.com
Halligan
Gregory E
GE
Punnett
Hope H
HH
McKenzie
Ann Shoemaker
AS
Guerrero
Felicula
F
de Chadarévian
J P
JP
D002051:Burkitt Lymphoma / Q000150:complications / Q000235:genetics*; D002675:Child, Preschool; D004171:Diploidy; D004314:Down Syndrome / Q000150:complications / Q000235:genetics*; D005260:Female; D006801:Humans; D007621:Karyotyping; D008297:Male