B-Cell Acute Lymphoblastic Leukemia with iAMP21 in a Patient with Constitutional Ring Chromosome 21.
Cytogenet Genome Res
; 162(5): 231-236, 2022.
Article
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| MEDLINE
| ID: mdl-36502796
ABSTRACT
Pediatric B-cell acute lymphoblastic leukemia (B-ALL) is associated with various specific cytogenetic and molecular markers that significantly influence treatment and prognosis. Intrachromosomal amplification of chromosome 21 (iAMP21) defines a rare distinct cytogenetic subgroup of childhood B-ALL, which is characterized by amplification of region 21q22.12 comprising the RUNX1 gene. Constitutional structural chromosomal abnormalities involving chromosome 21 confer an increased risk for B-ALL with iAMP21. Here, we report the development of B-ALL with iAMP21 in a 9-year-old child with a constitutional ring chromosome 21, r(21)c, uncovered after B-ALL diagnosis. Cytogenetic and microarray analysis of the post-therapy sample revealed an abnormal chromosome 21 lacking a satellite and having a deletion of the terminal 22q22.3 region, consistent with a constitutional ring chromosome 21, r(21)(p11.2q22). On a retrospective analysis, this ring chromosome was observed in the normal cells in the pre-treatment diagnostic specimen. Constitutional ring chromosome 21 may remain undetected in patients with mild or no neurodevelopmental phenotype, posing an unknown lifelong risk of developing B-ALL with iAMP21. Individuals with constitutional structural chromosome 21 rearrangements such as ring 21 require a close surveillance and long-term follow-up studies to establish their risk of B-ALL relapse and possibility of developing other malignancies. Germline analysis is recommended to all pediatric patients with iAMP21-related B-ALL to rule out structural chromosome 21 rearrangements and to elucidate molecular mechanisms of iAMP21 formation.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Cromosomas en Anillo
/
Leucemia-Linfoma Linfoblástico de Células Precursoras B
/
Leucemia-Linfoma Linfoblástico de Células Precursoras
Tipo de estudio:
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Límite:
Humans
Idioma:
En
Revista:
Cytogenet Genome Res
Asunto de la revista:
GENETICA
Año:
2022
Tipo del documento:
Article
País de afiliación:
Estados Unidos