Lovatel Viviane Lamim, da Silva Beatriz Ferreira, Rodrigues Eliane Ferreira, da Rosa Borges Maria Luiza Rocha, de Cássia Barbosa Tavares Rita, Bueno Ana Paula Silva, da Costa Elaine Sobral, de Jesus Marques Salles Terezinha, de Souza Fernandez Teresa
Cytogenetic Laboratory, Cell and Gene Therapy Program, Instituto Nacional do Câncer (INCA), Rio de Janeiro, RJ, Brazil.
Centro Oncohematologico Pediátrico, Hospital Universitário Oswaldo Cruz (HUOC), Recife, PE, Brazil.
Mediterr J Hematol Infect Dis. 2024 Jan 1;16(1):e2024003. doi: 10.4084/MJHID.2024.003. eCollection 2024.
Pediatric myelodysplastic syndrome (pMDS) is a group of rare clonal neoplasms with a difficult diagnosis and risk of progression to acute myeloid leukemia (AML). The early stratification in risk groups is essential to choose the treatment and indication for allogeneic hematopoietic stem cell transplantation (HSCT). According to the Revised International Prognostic Scoring System, cytogenetic analysis has demonstrated an essential role in diagnosis and prognosis. In pMDS, abnormal karyotypes are present in 30-50% of the cases. Monosomy 7 is the most common chromosomal alteration associated with poor prognosis. However, the rarity of specific cytogenetic alterations makes its prognosis uncertain. Thus, this study aimed to describe uncommon cytogenetic alterations in a cohort of 200 pMDS patients and their association with evolution to AML.
The cytogenetic analysis was performed in 200 pMDS patients by G-banding and fluorescence hybridization between 2000 to 2022.
Rare chromosome alterations were observed in 7.5% (15/200) of the cases. These chromosome alterations were divided into four cytogenetic groups: hyperdiploidy, biclonal chromosomal alterations, translocations, and uncommon deletions representing 33.3%, 33.3%, 20%, and 13.3%, respectively. Most of these patients (10/15) were classified with advanced MDS (MDS-EB and MDS/AML) and the initial subtype was present in five patients (RCC). The leukemic evolution was observed in 66.66% (10/15) of the patients. Most patients had poor clinical outcomes and they were indicated for HSCT.
The study of uncommon cytogenetic alterations in pMDS is important to improve the prognosis and guide early indication of HSCT.
小儿骨髓增生异常综合征（pMDS）是一组罕见的克隆性肿瘤，诊断困难且有进展为急性髓系白血病（AML）的风险。早期进行风险分层对于选择异基因造血干细胞移植（HSCT）的治疗方案和适应证至关重要。根据修订后的国际预后评分系统，细胞遗传学分析在诊断和预后判断中发挥着重要作用。在pMDS中，30%-50%的病例存在异常核型。7号染色体单体是与预后不良相关的最常见染色体改变。然而，特定细胞遗传学改变的罕见性使其预后难以确定。因此，本研究旨在描述200例pMDS患者中罕见的细胞遗传学改变及其与AML演变的关系。
2000年至2022年间，对200例pMDS患者进行了G显带和荧光原位杂交细胞遗传学分析。
7.5%（15/200）的病例观察到罕见染色体改变。这些染色体改变分为四个细胞遗传学组：超二倍体、双克隆染色体改变、易位和罕见缺失，分别占33.3%、33.3%、20%和13.3%。这些患者中大多数（10/15）被归类为晚期MDS（MDS-EB和MDS/AML），初始亚型见于5例患者（RCC）。66.66%（10/15）的患者出现白血病演变。大多数患者临床预后较差，适合进行HSCT。
研究pMDS中罕见的细胞遗传学改变对于改善预后和指导HSCT的早期适应证具有重要意义。
