Genetics Flashcards
What is the role of a dentist in genetic testing?
- Refer to clinical genetics and request tests
What does confirming a genetic diagnosis allow the dentist to give the patient?
- Can co-ordinate management
- Can give them information about the suspected condition
- Can give the patient options (treatment, etc)
- Can allow the patient to identify if there may be any risk to self or family members
How many pairs of autosomes are there in the human genome?
22 pairs
What is a chromosome?
A double-stranded DNA, coated with proteins
What does this pedigree symbol mean?:
White square with black border
Male
What does this pedigree symbol mean?:
White square with black border with diagonal line through it
Male who has died
What does this pedigree symbol mean?:
White circle with black border
Female
What does this pedigree symbol mean?:
Black square or circle
Affected male or female
What does this pedigree symbol mean?:
Half filled in square or circle
Carrier of disease
What does this pedigree symbol mean?:
Arrow pointing to square or circle
Proband - Person in the family that brings family to attention - where you notice something is wrong
What does this pedigree symbol mean?:
Square and circle with ===== (double line) connecting them
Consanguineous marriage - people who are in a partnership and are genetically related
What does this pedigree symbol mean?:
Square and circle with line connecting them that is scored out
Divorced couple
What does this pedigree symbol mean?:
White diamond
Pregnancy
What does this pedigree symbol mean?:
Black (filled in) diamond
Miscarriage
What are examples of SIMPLE genetic diseases?
Single gene mutations: - Autosomal dominant - Autosomal recessive - X-linked recessive (X-linked dominant) (Y-linked)
What are examples of COMPLEX genetic diseases?
- Multiple genes + environmental factors
- Multiple genes +/- chromosomal abnormalities
What does dominant mean?
Only need one faulty gene to get the disease
What does recessive mean?
Need both faulty genes to get the disease
What does knights move inheritance mean?
- Features:
- Two males related through UNAFFECTED female
- Only males are affected - tends to mean it is X chromosome recessive - Mode of inheritance:
- X-linked recessive (the female has an additional unaffected X chromosome which ‘protects’ her)
What does single nucleotide polymorphism mean?
The change in one base so a single letter in the genetic code is different from someone else’s
What effects can deletion; premature translation stop have?
Complete inactivation of a function of protein
What effects can AA substitutions in key regions, regulatory variants have?
Decreased function
What effects can non-coding DNA, no change in AA, alters less important region of protein have?
No significant effect
What effects can AA substitutions in key regions, regulatory variants or duplications have?
Increased function - variant actually has an advantage
