Genetics Flashcards
What are the signs of tuberose sclerosis?
periungual fibromata longitudinal ridging infantile seizures ash-leaf macule- earlies cutaneous sign (depigmented macule) hamartomas- an overgrowth of normal tissue (blood, muscles and fat) in heart lungs and kidneys bone cysts enamel pitting (teeth) shagreen patches
When mRNA is spliced, what is removed?
introns
What is a/ missense mutation
a point mutation in which a single nucleotide change results in a codon that gives a different amino acid
What is genetic heterogenity?
different mutations/genes can cause the same disease
What allows genetic heterogenity to happen?
DNA codes for different proteins which both take part in the same pathway
What is disease expression?
How people are affected by the disease
What is spidermolysis bullosa?
a group of genetic skin fragility conditions
What are the modes of inheritance of epidermolysis bullosa?
dominant, recessive, new mutation or acquired
What do the genes involved in epidermolysis bullosa coe for?
proteins involved in skin structure and adhesion
What is a dominant- negative disease mechanism?
mutant protein stops the normal protein working
What is haploinsufficiency?
one mutant disease doesnt produce any protein but normal copy does which results in less protein being produces
What are cafe au lait macules?
coffee coloured flat marks
Are cafe au lait macules always always suggestive of genetic disease?
no- 1 or 2 are found in normal people, more than 5 indicates genetic disease
What are the features of neurofibromatosis?
cafe au lait macules
neurofibromas
plexiform neuroma (subcut mass that feels like a “bag of worms”-benign tumour of peripheral nerves)
axillary or inguinal freckling (shouldnt get there as lack of sun)
optic glioma
lisch nodules- pigmented lesion affecting the irises
distinctive bony lesion
What is a genetic mutation associated with eczema?
mutation in the protein filaggrin which is a filmanet aggregating protein and prevents water loss
