Genetics in Medicine Flashcards
define human genetics?
the science of heredity and variation in humans and mechanisms of inheritance and genetic variation. Medical genetics is a subset of this that is important in medicine and medical research e.g. things of clinical importance
define molecular genetics?
the study of structure and function of individual genes including DNA
what happens when a gene does not perform its normal function correctly?
genetic disorder
what can cause inherited disorders?
single gene, imprinted, mitochondrial or chromosomal
what do genetic biomarkers show?
susceptibility to a certain disease
define pharmacogenetics?
who will respond, in what way, and why including their genes?
where can be drug treatments be targetted?
genetic faults which can be germline (Factor IX) or somatic (Imatinib)
what are the clinical genetics spectrums?
child - a lot of childhood disease is genetically determined
adult - often more complex
pregnancy - time limited
what does a family tree and clinical examination detect?
the pattern of inheritance, and the defining phenotype, and directs testing
what are the subsets of diagnostic tests?
non-genetic such as radiology or biochemistry, or genetic such as DNA and chromosomes
what is carrier testing used for?
autosomal and X-linked recessive
what test is done for inborn errors of metabolism?
enzyme assay - blood test
what test is done for thalaessemia?
haematological blood test
what test is done for achondroplasia?
skeletal dysplasia Xray
what DNA is tested in prenatal testing and why?
test the foetal DNA to prevent genetic disease
what is screening?
where a large number of people are tested to see if carrier and given the advice so they do not pass it on
what are some advantages of testing?
early diagnosis and interventions, and reproductive choices
what are some disadvantages of testing?
there may not be treatment, anxiety,
what proportion of children is hospital does rare disease account for?
1/4 to 1/3
what does KCNJ10 do?
it changes the ion currents in the brain and leads to epilepsy
what happens if there is a mutation in renal salt balance gene such as a mineralocorticoid receptor gene?
rare syndrome of blood pressure
what does epilepsy result from?
mutation in ion channels
what happens if the TNF alpha receptor gene is mutated?
autoimmune disorders
how does microcephaly arise?
mutation in the ASPM gene
which cells respond to blood glucose level?
beta cells
what enzyme converts glucose to glucose-6-phosphate generating ATP?
glucokinase
how is insulin released?
glucose-6-phosphate is an inhibitor of potassium channel, beta cells depolarised, calcium leaves and rise leads to degranulation of insulin to be released
what is MODY?
maturity onset diabetes of the young - mutation in glucokinase
what is neonatal diabetes caused by?
mutation in the potassium ion channel
where do sulfonylureas target?
potassium channel to treat NN diabetes
what is chronic myelogenous leukaemia?
it is when a hybrid gene is produced from translocation - abnormal tyrosine kinase - drug target this (chromosome 9 and 22 = Philadelphia chromosome)
