Applications of high-throughput DNA sequencing to benign hematology

Abstract

The development of novel technologies for high-throughput DNA sequencing is having a major impact on our ability to measure and define normal and pathologic variation in humans. This review discusses advances in DNA sequencing that have been applied to benign hematologic disorders, including those affecting the red blood cell, the neutrophil, and other white blood cell lineages. Relevant examples of how these approaches have been used for disease diagnosis, gene discovery, and studying complex traits are provided. High-throughput DNA sequencing technology holds significant promise for impacting clinical care. This includes development of improved disease detection and diagnosis, better understanding of disease progression and stratification of risk of disease-specific complications, and development of improved therapeutic strategies, particularly patient-specific pharmacogenomics-based therapy, with monitoring of therapy by genomic biomarkers.

Figure 1

WES in NA. Integrated genome browser view of reads from select regions of the VPS13A gene generated by exome sequencing. (A) Exon 69. Approximately half of full-length reads have A instead of G, leading to a missense mutation, thereby disrupting the exon 69 donor splice junction. (B) Exon 58. Approximately half of full-length reads lack 4 nucleotides, TAAG, corresponding to the end of exon 58 and the first nucleotide of intron 58.

Figure 2

Identifying hematologic diseases using WES. (A) Blood smear from a patient with HX demonstrates rare stomatocytes, target cells, and dessicytes (dense, erythrocytes with hemoglobin appearing to be puddled at the periphery). (B) WES identified mutations in PIEZO1, encoded by the FAM38A gene, as the HX disease locus. The location of this patient’s mutation is denoted by the arrow on a model of PIEZO1 created using hmmtop2 software. Adapted from Zarychanski et al with permission. (C) Blood marrow aspirate smear from a patient with DBA demonstrates only rare erythroblasts. (D) WES identified mutations in the GATA1 gene, leading to altered splicing and production of a short protein form of GATA1 protein (GATA1s) that lacks the NH2-terminal TD present in full-length GATA1. CF, COOH-terminal zinc finger; NF, NH2-terminal zinc finger; TD, transactivation domain. Adapted from Sankaran et al with permission.