Multiplex ligation-dependent probe amplification identifies copy number changes in normal and undetectable karyotype MDS patients

Jing Ma,Yong Yu,Yafei Wang,Chen Tian,Xiaofei Ai,Zeng Cao,Hongliang Yang,Zhigang Zhao,Jinhuan Wang,Limin Xing,Xiaofang Wang,Haifeng Zhao

doi:10.1007/s00277-021-04550-8

Abstract

Chromosomal abnormalities play an important role in classification and prognostication of myelodysplastic syndrome (MDS) patients. However, more than 50% of low-risk MDS patients harbor a normal karyotype. Recently, multiplex ligation-dependent probe amplification (MLPA) has emerged as an effective and robust method for the detection of cytogenetic aberrations in MDS patients. To characterize the subset of MDS with normal karyotype or failed chromosome banding analysis, we analyzed 144 patient samples with normal karyotype or undetectable through regular chromosome banding analysis, which were subjected to parallel comparison via fluorescence in situ hybridization (FISH) and MLPA. MLPA identifies copy number changes in 16.7% of 144 MDS patients, and we observed a significant difference in overall survival (OS) (median OS: undefined vs 27 months, p=0.0071) in patients with normal karyotype proved by MLPA versus aberrant karyotype cohort as determined by MLPA. Interestingly, patients with undetectable karyotype via regular chromosome banding indicated inferior outcome. Collectively, MDS patients with normal or undetectable karyotype via chromosome banding analysis can be further clarified by MLPA, providing more prognostic information that benefit for individualized therapy.

Highlights

Myelodysplastic syndrome (MDS) is a heterogeneous group of hematologic neoplasms classically described as a clonal disorder of hematopoietic stem cells leading to dysplasia and ineffective hematopoiesis in the bone marrow [1]
We addressed the question whether MDS patients with normal or without result after banding cytogenetics harbors cytogenetically cryptic gains or losses could be detected by Multiplex ligation-dependent probe amplification (MLPA)
The 144 MDS patients were divided into four subgroups based on MLPA and karyotype results; there were 86 males and 58 females

Summary

Introduction

Myelodysplastic syndrome (MDS) is a heterogeneous group of hematologic neoplasms classically described as a clonal disorder of hematopoietic stem cells leading to dysplasia and ineffective hematopoiesis in the bone marrow [1]. Ann Hematol (2021) 100:2207–2214 than 50% of low-risk MDS patients harbor a normal karyotype as revealed by regular chromosome banding analysis [2, 3]. MLPA is a multiplex polymerase chain reaction (PCR)-based technique that can quantify up to 50 different genomic targets simultaneously in a single experiment through amplification of specific hybridizing probes [4,5,6,7]. One of the major advantages is the high specificity, because it can distinguish sequences differing in length by only one nucleotide Another advantage is the low amount of input DNA (minimum of 20–50 ng) required for a successful MLPA reaction [8].

Methods

Results

Conclusion