Evaluation of TP53 and IGHV clinical molecular prognostic testing for patients with Chronic Lymphocytic Leukaemia at Tygerberg Hospital
type: CreativeWork
description: Introduction: Chronic lymphocytic leukaemia (CLL) is a monoclonal, lymphoproliferative malignancy with variable clinical outcomes and treatment responses, largely influenced by genetic and molecular factors. Among these, genomic DNA sequence variants in the tumour suppressor gene p53 (TP53) and mutational status of the immunoglobulin heavy chain variable region (IGHV) gene have emerged as critical molecular prognostic biomarkers with significant therapeutic implications for risk stratification and treatment selection. This study aimed to optimise, validate, and verify polymerase chain reaction (PCR)-based molecular assays for the detection of TP53 gene sequence variants and determination of IGHV mutational status in CLL patients at Tygerberg Hospital (TBH). Material & Methods: TP53 variant analysis was determined via bi-directional Sanger Sequencing of PCR-amplified complementary DNA (cDNA) obtained from reverse transcription of extracted total ribonucleic acid (RNA), targeting exons 2 to 11 of the entire coding region. IGHV mutational status was assessed using a two-step approach, firstly clonality was determined via fragment analysis by capillary electrophoresis of framework regions of the heavy chain variable region (FR1, FR2, FR3 VH), followed by bi-directional Sanger sequencing of clonal samples from genomic DNA (gDNA). A total of 44 participants were included in the evaluation according to National Health Laboratory Service (NHLS) validation guidelines. Results: The TP53 variant analysis assay had been successfully validated. Four variants were identified: c.108G>A (p.Pro36=), c.136T>C (p.Ser46Pro) and c.215C>G (p.Pro72Arg) in exon 4 and c.639A>G (p.Arg213=) in exon 6. Among 20 participants analysed, 25% carried c.108G>A (5/20), 5% carried c.136T>C (1/20), 50% carried c.215C>G (10/20) and 5% had both c.215C>G and c.639A>G (1/20) while 15% of participants had no variants (3/20). All variants were classified as benign on ClinVar except the c.136T>C variant which…
abstract: Introduction: Chronic lymphocytic leukaemia (CLL) is a monoclonal, lymphoproliferative malignancy with variable clinical outcomes and treatment responses, largely influenced by genetic and molecular factors. Among these, genomic DNA sequence variants in the tumour suppressor gene p53 (TP53) and mutational status of the immunoglobulin heavy chain variable region (IGHV) gene have emerged as critical molecular prognostic biomarkers with significant therapeutic implications for risk stratification and treatment selection. This study aimed to optimise, validate, and verify polymerase chain reaction (PCR)-based molecular assays for the detection of TP53 gene sequence variants and determination of IGHV mutational status in CLL patients at Tygerberg Hospital (TBH). Material & Methods: TP53 variant analysis was determined via bi-directional Sanger Sequencing of PCR-amplified complementary DNA (cDNA) obtained from reverse transcription of extracted total ribonucleic acid (RNA), targeting exons 2 to 11 of the entire coding region. IGHV mutational status was assessed using a two-step approach, firstly clonality was determined via fragment analysis by capillary electrophoresis of framework regions of the heavy chain variable region (FR1, FR2, FR3 VH), followed by bi-directional Sanger sequencing of clonal samples from genomic DNA (gDNA). A total of 44 participants were included in the evaluation according to National Health Laboratory Service (NHLS) validation guidelines. Results: The TP53 variant analysis assay had been successfully validated. Four variants were identified: c.108G>A (p.Pro36=), c.136T>C (p.Ser46Pro) and c.215C>G (p.Pro72Arg) in exon 4 and c.639A>G (p.Arg213=) in exon 6. Among 20 participants analysed, 25% carried c.108G>A (5/20), 5% carried c.136T>C (1/20), 50% carried c.215C>G (10/20) and 5% had both c.215C>G and c.639A>G (1/20) while 15% of participants had no variants (3/20). All variants were classified as benign on ClinVar except the c.136T>C variant which…
author: Nkwanyane, Tinashe Nthabiseng
language: en
date published: 2026-03
date modified: 2026-07-24T04:40:14Z
provider: Stellenbosch University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Stellenbosch : Stellenbosch University