Full Text Available

Note: Clicking the button above will open the full text document at the original institutional repository in a new window.

The role of Interferon regulatory factor 6 and Grainyhead-like 3 gene variants in South African patients with orofacial clefts

Dissertation (MSc (Human Genetics))--University of Pretoria, 2021.

Saved in:
Bibliographic Details
Other Authors: Jansen van Rensburg, Elizabeth
Format: Thesis
Language:English
Published: University of Pretoria 2022
Subjects:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1867613504797671424
access_status_str Open Access
author2 Jansen van Rensburg, Elizabeth
author_browse Jansen van Rensburg, Elizabeth
author_facet Jansen van Rensburg, Elizabeth
collection Thesis
dc_rights_str_mv © 2019 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.
description Dissertation (MSc (Human Genetics))--University of Pretoria, 2021.
format Thesis
id oai:repository.up.ac.za:2263/83310
institution University of Pretoria (South Africa)
language English
last_indexed 2026-06-10T12:37:12.475Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository
publishDate 2022
publishDateRange 2022
publishDateSort 2022
publisher University of Pretoria
publisherStr University of Pretoria
record_format dspace
source_str UPSpace — University of Pretoria Institutional Repository
spelling oai:repository.up.ac.za:2263/83310 The role of Interferon regulatory factor 6 and Grainyhead-like 3 gene variants in South African patients with orofacial clefts Jansen van Rensburg, Elizabeth u14105455@tuks.co.za Honey, Engela Seo, Sarah Orofacial cleft South Africa OFC-syndromes Orofacial clefts (OFC) Popliteal pterygium syndrome (PPS) UCTD Dissertation (MSc (Human Genetics))--University of Pretoria, 2021. Orofacial clefts (OFC) are one of the most common birth defects worldwide. The malformation is caused by disturbances in the developmental processes of the facial region from the fourth to tenth week of embryonic development. Varying disturbances in the fusion of the different facial regions result in different phenotypes of orofacial clefts. The global prevalence of orofacial clefts is 15.4 per 10,000 births. In a recent study of South African patients presenting at specialized academic treatment centres, the estimated prevalence of OFCs was 3 per 10,000 live-births. Deleterious variants in the IRF6- and GRHL3-genes have been identified as the cause of the two most common OFC-syndromes, Van der Woude (VWS) and Popliteal pterygium syndrome (PPS). In addition, both of the genes have been shown to cause non-syndromic/isolated cases of clefts. The only clinical difference between VWS and non-syndromic clefting is the presence of lip pits. In this retrospective study, patients with non-syndromic/isolated cleft lip and/or palate, who attended the University of Pretoria Facial Cleft Deformity Clinic, were investigated. A total of 91 patients (68 of African- and 23 of European ancestry) with isolated OFCs and no family history were screened for sequence variants in the IRF6 and GRHL3 genes, using Sanger sequencing. While no pathogenic IRF6 variants were found in non-syndromic CL/P cases of European ancestry, ~1.5% of non-syndromic CL/P cases of African ancestry were found to carry a pathogenic IRF6 variant. Two novel GRHL3 pathogenic variants, p.Asn336Ilefster1 and p.Tyr445Ter, were identified in non-syndromic cleft cases of African ancestry. Proven pathogenic GRHL3 variants, that include the previously mentioned two novel variants, account for 1.47% of cleft lip and palate and 2.94% of cleft palate only cases of African ancestry. These results are comparable to previously reported studies, further demonstrating the association between deleterious GRHL3 variants and cleft palate only cases. For patients of European ancestry, there were an equal number of cleft lip and palate and cleft palate only cases (4.35% each). In conclusion, this study represents the first investigation of both the IRF6 and GRHL3 genes in South African patients with isolated/non-syndromic orofacial clefts. To our knowledge, it is the first study to identify pathogenic variants in the IRF6 gene and the second study to identify pathogenic variants in the GRHL3 gene in South Africans of African or European ancestry, who have non-syndromic/isolated orofacial clefts. Of note, deleterious variants in III GRHL3 were five-fold more common than IRF6 deleterious variants in our cohort. Appropriate genetic counselling of the families with pathogenic variants will be carried out by Dr EM Honey. These results contribute further information on the role of these genes in isolated cases of orofacial clefts, especially in African populations. Genetics MSc (Human Genetics) Unrestricted 2022-01-13T07:01:49Z 2022-01-13T07:01:49Z 2022-04-29 2021 Dissertation * A2022 http://hdl.handle.net/2263/83310 en © 2019 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria
spellingShingle Orofacial cleft South Africa
OFC-syndromes
Orofacial clefts (OFC)
Popliteal pterygium syndrome (PPS)
UCTD
The role of Interferon regulatory factor 6 and Grainyhead-like 3 gene variants in South African patients with orofacial clefts
title The role of Interferon regulatory factor 6 and Grainyhead-like 3 gene variants in South African patients with orofacial clefts
title_full The role of Interferon regulatory factor 6 and Grainyhead-like 3 gene variants in South African patients with orofacial clefts
title_fullStr The role of Interferon regulatory factor 6 and Grainyhead-like 3 gene variants in South African patients with orofacial clefts
title_full_unstemmed The role of Interferon regulatory factor 6 and Grainyhead-like 3 gene variants in South African patients with orofacial clefts
title_short The role of Interferon regulatory factor 6 and Grainyhead-like 3 gene variants in South African patients with orofacial clefts
title_sort role of interferon regulatory factor 6 and grainyhead like 3 gene variants in south african patients with orofacial clefts
topic Orofacial cleft South Africa
OFC-syndromes
Orofacial clefts (OFC)
Popliteal pterygium syndrome (PPS)
UCTD
url http://hdl.handle.net/2263/83310