However, some people who brush every day seem to be prone to cavities while others, even some who may practice poor oral hygiene, seem to hardly ever get cavities.
There is increasing evidence that there is genetic risk factor relationship between dental caries and an individual phenotypic expression.
high levels in dysplastic lesions. EpCAM - tumor size, regional lymph node metastasis, histologic differentiation
1 where a mutation affects one gene. Sickle cell anemia is an example.2. where chromosomes (or parts of chromosomes) are missing or changed. Down syndrome is a chromosomal , 3.where there are mutations in two or more genes. Often your lifestyle and environment also play a role. Colon cancer is an example
It means one copy of altered gene is enough to cause the disorder. Gene present in chromosome 4. sh3 domain binding protein 3
RUNT related transcription factor .delayed loss of the primary (baby) teeth; delayed appearance of the secondary (adult) teeth; unusually shaped, peg-like teeth; misalignment of the teeth and jaws (malocclusion); and extra teeth, sometimes accompanied by cysts in the gums. Gene Instructions for making a protein that is involved in bone and cartilage development and maintenance. RUNX2 protein acts as a "master switch," regulating a number of other genes involved in the development of cells that build bones (osteoblasts).
underdevelopment of the middle of the face and the cheekbones (midface and malar hypoplasia) and micrognathia. Elongation factor tu GTP ase domain containing 2
Various cancerous and non cancerous tumour -dental effect- keratocyst odontogenic tumour, also associated with microdeletion of chromosome 9.. protein patched homolog 1(PTCH1)
Mutations in the COL1A1 and COL1A2 genes are responsible for more than 90 percent of all cases of osteogenesis imperfecta. CRTAP cartilage associated protein, prolyl hydroxylase 1, teeth is blue or brown opalscent pulp and root canals are completeor partial obliteration
Apert syndrome subnormal intelligence FGFR2- fibroblast growth factor receptor 2 dental anomalies high arched palate pseudo mandibular prognathism, crowding.. crouzen syndrome normal intelligence- less severe version
RET causes MENtype2 CDKN1B MEN type 4 type 1 involve parathyroid gland, pituitary gland pancreasWhen mutations inactivate MEN1 gene, menin is no longer available to control cell growth and division Mutations in the RET ( ret proto oncogene) which can trigger cell growth and division in the absence of signals from outside the cell. Mutations in the CDKN1B( cyclin dependant kinase inhibitor 1b)gene reduce the amount of functional p27, which allows cells to grow and divide unchecked
Schawannomin-schawann cells insulate nerve cells of brain and spinal cord..cafe lait spot and learning disabilities among NF1 cases is unclear.
The resulting uncontrolled cell growth, noncancerous growths called hamartomatous polyps in the gastrointestinal tract . STK11 serine theorinine kinase gene produces enzyme serine theorinine kinase also called liver kinase b1
ENAM enamelin, these genes helps in normal tooth development especially in enamel formation. Mutation lead to altered protein causing alterd enamel formationv
Mucus membrane and skin blisters easily.
-PORCN porcupine homolog protein coding gene.. affects the skin, skeleton, eyes, and face. Facial asymmetry with cleft lip and palate, syndactyly, microopthalmia and papilomas ,,cannot participate in abnormal signaling pathway
Dentin sialophosphoprotein –DSPP forms dentin sialoprotein , dentin phosphoprotein
Hutchinson-Gilford progeria syndrome is a autosomal dominant condition characterized by the dramatic,
Prospective disease has not occurred in family. Retropective have occurred mostly comes chid with congenital deformities.
Oral health and genetics
Oral health and
Genetics Dr Sharanya Sreekumar
Post graduate student
Department of Public Health
Laws of inheritance by Mendel
Genetics and dental caries
Genetics and periodontitis
Genetics and oral cancer
Classification of genetic disorders
Genetic disorders of oro-facial region
• Disorders of jaw bones
• Disorders of oral mucosa
• Disorders of affecting enamel
• Disorders affecting dentine
• Miscellaneous disorders
The word genetics is derived from ancient Greek “genesis” meaning the origin
Imre Festetics was first person to term word genetics before Mendel.
Genotype- is the total genetic constitution of an individual
Phenotype- refer to a specified character
Chromosome: are rod-like condensations of chromatin.
They become visible in the nucleus only during cell division
Genes: are fundamental units of inheritance
Modern genetics start with Gregor Johann Mendel.
His works on monohybrid and dihybrid cross level on garden peas mentioned 3
laws of inheritance
Law of dominance
Law of segregation
Law of independent assortment
Genetics in oral health
Everything from the alignment of your teeth to their strength can be linked to
The reasons for this disparity are numerous, but one of the key factors is a person’s
Genetics and dental caries
Children manifest the mother’s immune system for the first months of life
This acquired immune system is not particularly effective against strains of
S mutans in the mother
Inherited disorders increases chance of caries.
“genetic factors play an appreciable part in determining individual resistance against
dental caries". ( Book and Grahen, 1953)
Twin studies Finn and Caldwell in 1963, found that smooth surface lesion under
genetic strict control.
Genetics and periodontitis
In periodontitis, the host- activated inflammatory and immunological cascades,
which result in the destruction of connective tissue and bone are under genetic
In a large, five-generation family, an autosomal-dominant form of localized juvenile
periodontitis was ascertained to be linked to Gc (group-specific component, a
vitamin-D-binding protein locus) on the long arm of chromosome 4 (4q) (Boughman
et al, 1986)
Genetics and oral cancer
Oral carcinogenesis is a multifactorial process involving numerous genetic
processes that can alter the function of
tumor suppressor genes, and other related molecules.
These changes causes loss of tumor suppressor activity and give rise to a phenotype
increasing cellular proliferation,
weakening cell cohesion and
causing local infiltration and metastasis.
More than 90% of oral cancer is oral squamous cell carcinogenesis which caused
due to genetic alterations
Other molecules associated are
There are three types of genetic disorders:
Chromosomal disorders disorder
Genetic test on blood and other tissue can identify genetic disorders
Amniocentesis genetic test.
Genetic disorders of oro facial regions
Most of the disorders affecting orofacial region are autosomal dominant trait
Disorder mainly affects jaws, dental tissues and oral mucus membrane
Disorders of Jaw bones
It is a autosomal dominant disorder
Caused due to mutation SH3BP2 gene.( 80% cases)
causes inflammation in the jaw bones and triggers the production of osteoclasts
It a autosomal dominant disorder affecting development of bones and teeth.
Mutation of RUNX2 gene
abnormally short protein or gene is missing
Interferes with normal protein growth and development
Treacher Collins syndrome( mandibulo facial dysostosis)
Autosomal dominant trait
mutation of gene EFTUD2
Spliceosomes helps process of messengerRNA
impairs RNA processing
Nevoid basal cell carcinoma syndrome
It is autosomal dominant trait
Mutation of PTCH 1 gene occurs
Prevent production of patched-1
Cannot effectively suppress cell
growth and division
Cell grow uncontrollably to form
It is autosomal dominant trait and sometimes have a recessive trait
8 types have been identified.
Mutations in the COL1A1, COL1A2,
CRTAP, and P3H1 genes
Reduces amount of type 1 collagen
Causes brittle bones, defective CT
Autosomal dominant trait
Mutation in FGFR 2 gene
Alters FGFR287100 protein
Leads to prolonged signaling
Promote fusion in skull, hand and feet
Multiple endocrine neoplasia syndrome
Tumors produced in endocrine glands.
Mutations in the MEN1 type 1 MEN Menin protein
RET gene type 2 MEN over activate protein signaling
CDKN1B genes type 4 MEN ses amount of functional p27
NF type 1 autosomal dominant
Mutations in the NF1 gene
nonfunctional version of neurofibromin
cannot regulate cell growth and division.
neurofibromas forms along nerves
Inherited in autosomal dominant pattern
Mutation of STK11 gene
alters the structure or function of the STK11 protein
disrupting its ability to restrain cell division.
formation of noncancerous polyps and cancerous tumors
14 forms of amelogenesis imperfecta.
Mutations in the AMELX, ENAM, MMP20, and FAM83H genes
tooth enamel is abnormally thin or soft
malfunction of the proteins in the enamel: ameloblastin, enamelin, tuftelin and
Very less or no enamel
Snow capped teeth
Soft and easily removable
Hypoplasic hypomaturation with taurodontism
Oculo-dento digital Dysplasia
Inherited autosomal dominant pattern
Usually autosomal dominant pattern
4 major types
mutations in either the KRT5 or KRT14 gene.
Prevent the keratin proteins from assembling into strong networks
causing cells in the epidermis to become fragile and easily damaged.
the skin is less resistant to friction and minor trauma and blisters easily.
Focal dermal hypoplasia
It is X-linked dominant pattern that primarily
Mutations in the PORCN gene
prevent the production PORCN protein
Wnt proteins cannot be released from the cell
Interuptes normal development
DI type 2 and 3 caused to mutation of gene DSPP
The DSPP gene provides two proteins that are essential for normal tooth
DSPP gene mutations
alter the proteins made from the gene
production of abnormally soft dentin.
DI type 1 associated with osteogenesis imperfecta
Rh incompatablity caused due to mutation of RHAG gene( Rh associated
It leads to chronic hemolytic anaemia due to defect in RBC formed.
Progeria( Hutchnison Gliford syndrome)
rapid appearance of aging beginning in childhood
Mutations in the LMNA gene
production of an abnormal version of the lamin A protein.
nuclear envelope unstable and progressively damages the nucleus
making cells more likely to die prematurely
It is autoimmune disorder
IRF5 and STAT4, are also associated with an
increased risk of developing systemic scleroderma
a combination of genetic and environmental factors seems to play a role in
developing systemic scleroderma
Van der woude syndrome
Autosomal dominant condition
A shortage of the IRF6 protein affects the development and maturation of tissues in
is a communication process in which trained professionals help individuals and
families deal with issues associated with the risk of or occurrence of a genetic
Prospective and Retrospective genetic counselling
The traditional epidemiologic approach has proved useful for generating
hypotheses and unraveling disease etiologies. But now it is possible to go beyond
these methods and look inside the genetics of the disease process which would be
able to change the definition of the risk factors or clarify their location in the
casual model. The control of genetic diseases should be based on an integrated
and comprehensive strategy combining best possible treatment and prevention
through community education, population screening, genetic counseling, and the
availability of early diagnosis
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