Publications by authors named "Maham Arshad"

3 Publications

  • Page 1 of 1

POLE and POLD1 pathogenic variants in the proofreading domain in papillary thyroid cancer.

Endocr Connect 2020 Oct;9(9):923-932

Human Cancer Genomic Research, Research Centre, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.

Thyroid cancer is the most frequent endocrine cancer with an increasing incidence rate worldwide and is the second most common malignancy among females in Saudi Arabia. Papillary thyroid cancer (PTC) is the most common subtype. Germline pathogenic variants in the proofreading domain of the POLE and POLD1 genes predispose to several types of cancers. However, the role of pathogenic variants of these two genes in PTC remains unknown. Capture sequencing, Sanger sequencing and immunohistochemistry were performed on 300 PTC cases from the Middle Eastern region. One germline pathogenic variant each of POLE (1/300, 0.33%) and POLD1 (1/300, 0.33%) genes was identified. Low expression of POLD1 was detected in 46.5% (133/286) of cases and was significantly associated with the follicular variant of PTC (P = 0.0006), distant metastasis (P = 0.0033) and stage IV tumours (P = 0.0081). However, no somatic pathogenic variant was detected in POLE gene. Furthermore, low expression of POLE was noted in 61.7% (175/284) of cases with no significant clinicopathological associations. Our study shows that pathogenic variant in the POLE and POLD1 proofreading domain is a cause of PTC and low expression of POLD1 is associated with poor prognostic markers in the Middle Eastern population. Further studies from different geographic populations are needed to determine the frequency and spectrum of proofreading domain pathogenic variants in POLE and POLD1 genes and in PTC from different ethnicities.
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http://dx.doi.org/10.1530/EC-20-0258DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7583138PMC
October 2020

POLE and POLD1 germline exonuclease domain pathogenic variants, a rare event in colorectal cancer from the Middle East.

Mol Genet Genomic Med 2020 08 22;8(8):e1368. Epub 2020 Jun 22.

Human Cancer Genomic Research, Research Center, King Faisal Specialist Hospital and Research Center, iyadh, Saudi Arabia.

Background: Colorectal cancer (CRC) is a major contributor to morbidity and mortality related to cancer. Only ~5% of all CRCs occur as a result of pathogenic variants in well-defined CRC predisposing genes. The frequency and effect of exonuclease domain pathogenic variants of POLE and POLD1 genes in Middle Eastern CRCs is still unknown.

Methods: Targeted capture sequencing and Sanger sequencing technologies were employed to investigate the germline exonuclease domain pathogenic variants of POLE and POLD1 in Middle Eastern CRCs. Immunohistochemical analysis of POLE and POLD1 was performed to look for associations between protein expression and clinico-pathological characteristics.

Results: Five damaging or possibly damaging variants (0.44%) were detected in 1,135 CRC cases, four in POLE gene (0.35%, 4/1,135) and one (0.1%, 1/1,135) in POLD1 gene. Furthermore, low POLE protein expression was identified in 38.9% (417/1071) cases and a significant association with lymph node involvement (p = .0184) and grade 3 tumors (p = .0139) was observed. Whereas, low POLD1 expression was observed in 51.9% (555/1069) of cases and was significantly associated with adenocarcinoma histology (p = .0164), larger tumor size (T3 and T4 tumors; p = .0012), and stage III tumors (p = .0341).

Conclusion: POLE and POLD1 exonuclease domain pathogenic variants frequency in CRC cases was very low and these exonuclease domain pathogenic variants might be rare causative events of CRC in the Middle East. POLE and POLD1 can be included in multi-gene panels to screen CRC patients.
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http://dx.doi.org/10.1002/mgg3.1368DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7434734PMC
August 2020

Effect of Iron Deficiency on the Phenotype of β-Thalassaemia Trait.

J Coll Physicians Surg Pak 2016 Mar;26(3):230-1

Department of Haematology, Armed Forces Institute of Pathology, Rawalpindi.

The objective of this study was to determine the effect of iron deficiency on Hb-A2 level in β-thalassaemia trait and to determine the frequency of individuals with β-thalassaemia trait who could be missed due to concomitant iron deficiency. A total of 120 patients were studied, out of which 23 were iron deficient (serum ferritin < 20 ng/ml). Mean Hb-A2 in the iron deficient individuals was 4.1 ± 0.47% as compared to 5.1 ± 0.58% in the remaining 97 individuals without iron deficiency (p < 0.001). In the 120 individuals with β-thalassaemia trait, mean Hb-A2 was 5.8% with range 3 - 6.8% and confidence interval was 95%. In 2 individuals with β-thalassaemia trait, Iron deficiency was observed and showed Hb-A2 less than 3.5%. These could have been missed while screening by Hb-A2 estimation alone. Co-existence of Iron deficiency and β-thalassaemia trait may mask the diagnosis of beta thalassaemia trait and such individuals can be missed during screening by Hb-A2 estimation alone.
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http://dx.doi.org/03.2016/JCPSP.230231DOI Listing
March 2016