Hart and Hart (2016) Human Genetics in Dental School PDF

INVITED COMMENTARY Invited commentary: The need for human genetics and genomics in dental school curricula P. Suzanne Hart1 & Thomas C. Hart2 1 National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland 2 American Dental Association Foundation, Volpe Research Cent...

INVITED COMMENTARY Invited commentary: The need for human genetics and genomics in dental school curricula P. Suzanne Hart1 & Thomas C. Hart2 1 National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland 2 American Dental Association Foundation, Volpe Research Center, Gaithersburg, Maryland doi: 10.1002/mgg3.216 There are currently 67 dental schools in the United States practice. These genetic disorders may or may not have an and Puerto Rico. According to the 2014 edition of the impact on their oral health. These include Mendelian Official Guide to Dental Schools For Students Entering in traits such as amelogenesis imperfecta and cystic fibrosis, Fall 2015 published by the American Dental Education cytogenetic disorders such as Smith–Magenis and Wil- Association (www.adea.org), no dental schools currently liams syndromes, as well as multifactorial traits such as require genetics prior to admission. Only one school, the cleft lip/cleft palate or diabetes. The last decade has seen University of Florida, requires one semester of molecular an explosion in the number of genes associated with cran- biology or genetics for admission. When last surveyed in iofacial development and diseases. Currently, mutations 2001, only eight of 53 dental schools had a formal course in at least seven genes are associated with amelogenesis in human genetics in their curricula (Dudlicek et al. imperfecta, a disorder of qualitative or quantitative 2004). Only one school did not respond to the survey. defects of enamel (Table 1). Despite calls from a variety of individuals and profes- There are several reasons why genetics and genomics sional organizations that genetics should be an integral should be included in dental school criteria beyond the part of dental school curricula (Wright and Hart 2002; obvious value of making a dental diagnosis. Being able to Behnke and Hassell 2004; Collins and Tabak 2004; John- take a family history to construct a three-generation pedi- son et al. 2008; Slavkin 2014), little progress has been gree is crucial. While one should not discount the psy- made to improve the teaching of human genetics to den- chological or financial burden of missing or malformed tal students. With this in mind, we once again call for teeth, genetic disorders may also have extraoral health dental schools to include human genetics as a formal consequences. For example, dentinogenesis imperfecta course in their curricula. (DI) may occur as an isolated finding or as part of a syn- A search of the scientific literature reveals how the con- drome such as osteogenesis imperfecta (OI), which is tribution of genetic factors to missing or misshapen teeth, associated with bone fragility and hearing loss (Hart and cleft lip/palate, oral cancer, caries, periodontal disease and Hart 2007). Mild type 1 OI may be mistaken for isolated other oral pathologies and conditions continues to DI (Pallos et al. 2001). Making a correct diagnosis is cru- expand. The effects that systemic disorders can have on cial for a discussion of phenotypic consequences, manage- an individual’s oral health are also well known. Gingival ment, and genetic counseling for recurrence risks. Enamel hyperplasia can be an isolated condition, part of a syn- drome, or a side effect of certain medications. If a side Table 1. Genes that Cause Amelogenesis Imperfecta. effect of medication, it is reversible simply by stopping the drug. Inherited forms require surgical resection. Thus, Gene Chromosome Mode of inheritance a dentist needs to able to take a family and medical his- Kallikrein 4 (KLK4) 19 Autosomal Recessive tory to distinguish the forms. Associations have been Enamelin (ENAM) 4 Autosomal Dominant made between enamel defects and kidney disease (Jau- and Autosomal Recessive reguiberry et al. 2013), between missing teeth and colon WD Repeat Domain 15 Autosomal Recessive cancer (Lammi et al. 2004), and between microdontia 72 WDR72 and deafness (Riazuddin et al. 2011). Knowing whether a Matrix Metalloproteinase 11 Autosomal Recessive dental phenotype is an isolated finding or is associated 20 (MMP20) FAM20A 17 Autosomal Recessive with other systemic manifestations with broader health- FAM83H 8 Autosomal Dominant care implications can lead to appropriate referrals. Den- Amelogenin (AMELX) X X-linked tists clearly have patients with genetic disorders in their ª 2016 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals, Inc. 123 This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. Invited Commentary P. S. Hart & T. C. Hart renal syndrome is an autosomal-recessive disorder due to important facet of patient-educators is bringing to light mutations in the FAM20A gene. The combined dental the psychosocial aspects of a particular disorder. Given features of amelogenesis imperfecta and gingival hyper- the huge cosmetic side of dentistry, this psychosocial plasia are highly suggestive of this disorder. The renal aspect should not be overlooked. Studies have shown that phenotype, nephrocalcinosis, is typically clinically asymp- students often learn faster and are more empathetic when tomatic in children. Dentists should refer individuals with patient-educators are involved (Renard et al. 2015). We the oral phenotype to nephrologists for evaluation (Jau- believe that incorporation of patient-educators should be reguiberry et al. 2013). Mutations in the ANIX2 gene adopted at some level in all dental schools. have been associated with oligodontia and colorectal can- Health care providers cannot work in a vacuum. The cer (Lammi et al. 2004). Although not all patients with dental practitioner needs to know where to go to look for oligodontia have an increased risk of colorectal cancer, a genetic resources. When appropriate, the dentist should history of colorectal cancer in the blood relatives of an be part of the personalized medicine team. They need to oligodontia patient should prompt consideration of refer- be able to speak the language and understand basic con- ral to either a genetic counselor or clinical geneticist for cepts in order to interact with other members of the team further evaluation. in a meaningful way. This lack of genetics education lim- Dentists also need to have an understanding of genetics its the dentist’s ability to interact with the larger health to appreciate the issues surrounding genetic testing. More care team, further isolating dentistry from other health than 3000 genetic tests currently available encompass a care disciplines. This isolation is confounded by separate variety of genetic disease types. The majority of these tests health care records and distinct reimbursement systems for Mendelian and cytogenetic conditions are clinically (Regier and Hart 2016). valid and useful; however, they must be used properly. In summary, dental graduates should have the basic Unfortunately, some of the tests offered, particularly tests genetics knowledge and skills to provide the educational for small effect SNP variants marketed to predict risk for foundations for understanding and applying genetics to common, complex diseases are neither clinically valid nor clinical practice. While the genetic core competencies for clinically useful (SACGT 2000; Diehl et al. 2015; Ioannidis such knowledge, skills, and attitudes will need to be devel- 2015). The dental provider will need to be able to evalu- oped for the dental profession, examples have been devel- ate these tests and decide whether or not to incorporate oped by others, including recommended core competencies them into their clinical practice. In many cases, this will in genetics for all health care professionals (Jenkins et al. involve consultation with non-dental health care provi- 2001; NCHPEG 2007). The failure of dental schools to ders, including geneticists and genetic counselors. incorporate human genetics into their curricula is a failure As our understanding of genetics and the role of to their students who will surely encounter patients with genetic factors in normal and abnormal development genetic disorders in their practice. Students without ade- increases, it is imperative that dental students are taught quate training in genetics will not be prepared to effectively more than just Mendelian and cytogenetic disorders. Den- diagnose patients, adequately evaluate new therapies or tists need to understand multifactorial conditions as well tests based upon genomic information, nor work collabora- as appreciate how environmental exposure to microbial, tively with other members of the health care team. In the viral, pharmacologic, diet, smoking, and other factors can end, it will be the patients who suffer. affect the genetic and epigenetic landscape (Ambatipudi et al. 2016). This is particularly true for the dental care References providers where smoking and the oral microbiome have a Ambatipudi, S., C., Cuenin, H. Hernandez-Vargas, A. direct impact on the development of caries, periodontal Ghantous, F. L. Calvez-Kelm, R. Kaaks, et al. 2016. Tobacco diseases, and other oral pathologies. smoking-associated genome-wide DNA methylation changes The patient-educator model, in which patients tell their in the EPIC study. Epigenomics. [Epub ahead of print] own stories to dental students, is a way to better engage PMID: 26864933 learning and retention of knowledge. Although used Behnke, A. R., and T. M. Hassell. 2004. Need for genetics extensively in the training of medical students and resi- education in U.S. dental and dental hygiene programs. J. dents, this is a fairly new practice in dentistry (Renard Dent. Educ. 68:819–822. et al. 2015). The authors of this study report that patient- Collins, F., and L. Tabak. 2004. 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