DTH24 Human Genetics slides copy.pdf

In partnership with Human Genetics Relevance in Dentistry Jiann Khaw Tutor Dentist  A brief introduction to The human genetics and its Aim relevance in dentistry 2 Learning Outcomes: At the end of this session, you should be able to: 1.Describe basic...

In partnership with Human Genetics Relevance in Dentistry Jiann Khaw Tutor Dentist  A brief introduction to The human genetics and its Aim relevance in dentistry 2 Learning Outcomes: At the end of this session, you should be able to: 1.Describe basic principles of human genetics 2.Identify the impact of gene mutation in humans 3.Recognise the relevance of human genetics in dentistry GDC Learning Outcome: 1.1, 1.1.3, 1.7.2, 7.1, 7.2 C1.4, C1.5, C1.32, C2.2.1, P1.5 3  Human Genetics Introduction to Basic Principles 4 "DNA strand" by M Pinarci is licensed under CC BY 2.0  Genomics vs Genetics Why have this distinction? Image source: Genomics Education, Health Education England 5 Impact of Human Genome Project on Healthcare The Human Genome Project Timeline and History (Image source: www.genomicsforeveryone.org) 6 Mendel’s Principle of Inheritance Image source: Sciencia58 , CC0 1. Characters (phenotype) are distinct 2. Genetic characteristic (alleles) have alternate forms 3. Phenotype reflects ‘dominant’ allele 4. Random segregation of alleles 7 Human Chromosomes Key facts: ✓ 23 pairs of chromosomes ✓ Each half is inherited from both parents ✓ Each chromosomes have multiple genes ✓ Each gene is sequenced by DNA – AT, GC 8  Purpose of Gene? Image Source: Glick (2015) in Burket’s Oral Medicine 9 Purpose of a gene? Blueprint codes to create proteins (DNA) Effect on development Determines structure of protein Controls where, when and quantity of protein needed and function of the body/cell Cell function of body -repair tissues -enzymes which causes chemical reaction (e.g. starch digestion) -stimulate / suppress multiplication of cells 10 Protein Synthesis Watch animated video - Click on link below to access ‘The animated genome’ by Sanan Media: https://www.unlockinglifescod e.org/media- gallery/animated-genome (Accessed: May 2024) Image source: BBC Bitesize 11 Proteins acting on stem cells leading to other cell formation, differentiation and function 12  Human Genetics Impact of Variant or Mutation 13 "TAGTAT" by francisco.j.gonzalez is licensed under CC BY 2.0 Why gene variant or mutation occurs? Non-Inherited Inherited Occurs in somatic cells (somatic variants) Passed from parent to child Occurs at some point in an individual’s life Variant gene was present from birth Variants cannot be passed to child Phenotype not expressed if recessive gene Caused by environmental factors (e.g. X- Individual may be a carrier radiation in medical examination, UV from sun) Error in DNA replication during cell division 14 Image Source: Glick (2015) in Burket’s Oral Medicine 5 types of Mutation  No change to encoded amino acid sequence  Single change to encoded amino acid sequence  Translate ‘STOP’ codon, leading to truncation of amino acid sequence  Change in encoded amino acid sequences at point of mutation leading to formation of different codons 15 Medical Condition Single Gene Change Image source: BBC News Cystic Fibrosis - mutation of both copies of CF Transmembrane Conduction Regulator [CFTR] Image source: HBO Achondroplasia -mutation of Fibroblast Growth Factor Receptor 3 [FGFR3] 16 Medical Condition Genetic variant (or defect) "Sickle cell blood smears" by scooterdmu is licensed Image source: Wellcome Collection under CC BY 2.0 Sickle Cell Anaemia – Down Syndrome –Trisomy 21 autosomal recessive Beta-globin gene 17 Dental Condition Some examples resulting from genetic condition Hypodontia Hyperdontia (Supernumery) Microdontia Macrodontia Macroglossia Amelogenesis Imperfecta Dentinogenesis Imperfecta 18 Explore further impact of human genetics: https://podcasts.apple.com/g b/podcast/episode-4-the- genetic-revolution- implications/id1539658870?i= 1000654905473 (Accessed: May 2024) https://www.bbc.co.uk/programmes/m000sthc Click on link to watch: BBC documentary on DNA Family Secrets Hosted by Stacey Dooley (Accessed: May 2024) 19  Human Genetics Relevance in Dentistry 20 "A Unique Routine for Preparing for the Dentist Office" by idaknight316 is licensed under CC BY 2.0 Relevance of Genetics in Dentistry 1. Professional development 2. Care provision 3. Legal, Ethical & Social Image source: NHS England 21 Relevance of Genetics in Dentistry 1. Professional development ▪ Influences on human development ▪ Recognise origins of effects seen clinically 2. Care provision ▪ Aid in diagnosis of disease condition 3. Legal, Ethical & Social ▪ Anticipate care options ▪ Communicate with healthcare colleagues ▪ Genomic services and associated infrastructure 22 Professional development: Covid-19 Vaccination Hypodontia – common in Down Syndrome 23 Relevance of Genetics in Dentistry 1. Professional development ▪ Routine dental care for patient with genetic conditions 2. Care provision ▪ Discussion about dental condition 3. Legal, Ethical & Social related to genetics ▪ Risks – condition, care modalities, susceptibility vs resistance ▪ Saliva Test kits – Caries risk, Periodontal Disease risk, Cancer risk, etc. ▪ Availability? Safety? Validity? Effectiveness? 24 Care provision: Brinkley et al. (2009) JADA, 140 (7): pp.896-905. 25 Relevance of Genetics in Dentistry 1. Professional development ▪ Privacy of genetic information ▪ Affordability & Access = Fairness? 2. Care provision ▪ Social + Emotional support for patients & 3. Legal, Ethical & Social carers ▪ Genetic counselling = risk to unborn child 26  Gene Therapy Press Association (2021) Weston (2021) in The Roberts (2024) in BBC News - Click here for full Guardian News - click - click here for full article. article. here for full article. (Accessed: May 2024) (Accessed: May 2024) (Accessed: May 2024) 27  Principles of Function of inheritance Proteins Human Genetics Mutation Summary Relevance in Dentistry and Link to: Variants Embryology Oral Diseases Cell body development Adaptation of diagram by S.Balian (2021) 28 Bibliography for this presentation: 1. Brinkley, C.J., Beacham, A., Neace, W., Gregg, R., Liem, E. and Sessler, D. (2009) Genetic variation associated with red hair color and fear of dental pain, anxiety regarding dental care and avoidance of dental care. JADA, 140(7), pp. 896-905. DOI: 10.14219/jada.archive.2009.0283 2. Hart, P.S. and Hart, T.C. (2016) Invited commentary: The need for human genetics and genomics in dental school curricula. Mol Genet Genomic Med, 4, pp. 123-125. DOI: 10.1002/mgg3.216 3. Neves, V., Pugh, J. and Savulescu, J. (2021) Beyond oral hygiene, are capacity-altering, biologically based interventions within the moral domain of dentistry?. Br Dent J, 231 (5), pp. 277–280. DOI: 10.1038/s41415-021-3335-y 4. Siddique, N., Raza, H., Ahmed, S., Khurshid, Z. and Zafar, M.S. (2016) Gene Therapy: A Paradigm Shift in Dentistry. Genes, 7 (11), 98, pp. 1-12. DOI: 10.3390/genes7110098 5. Slavkin, H.C., Navazesh, M. and Patel, P. (2015) Basic Principles of Human Genetics: A Primer for Oral Medicine, in Glick, M.(Ed) Burket’s Oral Medicine. 12 th Edition. USA: People’s Medical Publishing House, pp. 625-652. 6. Waugh, A. and Grant, A. (2018) Chapter 17: Introduction to genetics. Ross & Wilson Anatomy And Physiology In Health And Illness. 13th Ed. Edinburgh: Elsevier, pp. 475-486. 7. Williams, L.A., Davis-Dusenbery, B.N. and Eggan, K.C. (2012) SnapShot: directed differentiation of pluripotent stem cells. Cell, 149 (5), pp. 1174-1174.e1. DOI: 10.1016/j.cell.2012.05.015. 29  Human Genetics Student Activities 30 "DNA strand" by M Pinarci is licensed under CC BY 2.0  Moodle Activities: 1. Share one foreseeable challenge in providing oral health care for a patient with Treacher Collins or Down Syndrome in the group discussion forum 2. Complete the quiz section to test your knowledge on this session 31 "Victorian Dentist - II" by thy is licensed under CC BY 2.0