Genetics Flashcards
what is the important of precision medicine
used to identify subgroups of patients who will respond to treatment
what is a genodermatoses
skin condition caused by well defined genetic cause
what is tuberous sclerosis
genodermatoses- presents as infantile seizures (caused by cortical tumours- may also cause mental impairment), ash leaf molecules in skin, peuringual fibromata and longitudinal ridging in nails, facial angiofibromas, hamartomas, bone cysts, enamel pitting
what are angiofibromas
erythematous papules- often misdiagnosed as acne but doesnt have comedones
what is the inheritance pattern of tuberous sclerosis
autosomal dominant
multi gene disorder (chromosomes affecting tuberin, hamartin and tumour regulation)
what is a denovo mutations
mutation that is present for the first time in a specific family member
what is the risk of a child getting a autosomal dominant disorder if a parent has it
50%
what is variable penetrance
a child with affected parent may not shoe disease
who is most likely to get an autosomal dominant disorder males or females
both same chances
what is wild type
typical phenotype of a species as it occurs in nature
what is a missense mutation
a point mutation that results in a codon which codes for a different amino acid
what is a nonsense mutation
when codon changed to a ‘stop’ codon
what is a frameshift mutation
one that changes all the codes for amino acids by making DNA sequence indivisible by three
what is penetrance
proportion of individuals carrying particular genotype that also expresses the phenotype
what is epidermolysis bullosa
group of genetic skin fragility conditions
what is the inheritance pattern of epidermolysis bullosa
can be dominant, recessive, acquired or new mutation
what are the three main types of epidermolysis bullosa
simplex (splits in epidermis)
junctional (DEJ)
dystrophic (dermis)
what genes are affected in epidermolysis bullosa
one controlling skin structure and adhesion
- keratin 5, 14
- laminins
- integreins
- collagen 17
why do you need 2 types of keratin
to form dimer which then forms filament
what is Haploinsufficiency
(autosomal dominant) when one copy of an allele doesnt produce enough protein
what is a dominant-negative disease mechanism
where mutation in one gene causes normal protein to stop working (normal gene interfered with mutant gene)
what is gain of function
mutant protein gains a new function affecting cell processes
what is complete loss of protein
autosomal recessive- 2 faulty copes of gene produce no protein
if both parents are carrier of an autosomal recessive condition, what are the chances of a child getting it
1 in 4
