genetics and imaging Flashcards
(32 cards)
if horizontal appearance of phenotype between siblings, likely what type of genetics
autosomal recessive
mitochondrial inheritance is transmitted by mum or dad
mum only - fathers do not transmit mitochondrial genes
how is mitochondrial inheritance different from mitochondrial disease
mitochondrial disease can be passed down by mum or dad, bc there are mitochondrial genes in the nuclear genome
enzyme deficient in albinism
tyrosinase
what is osteogenesis imperfecta, what is main effect of mutation
defect in collagen causes kink and prevents strand alignment, main effect is brittle bones, autosomal dom or reces
ehlers danlos syndrome, type of inheritance
mutations in collagen infer tendon flexibility, autosomal dom
prenatal testing for what genetic disease
PKU
congenital hypothyrodism
CF
galactosaemia
PKU and CF inheritance pattern
autosomal rec
what is problem in PKU
lack of phenylalanine hydroxylase leads to elevated phenylpyruvate which damages brain (and inhibits tyrosinase)
what do you test for to test for CF
elevated immunoreactive trypsinogen
cretinism
primary congenital hypothyroidism
what is most common cause of preventable intellectual disabiliyt
primary congenital hypothyroidism
when in development do you have embryonic vs foetal Hb
embryonic 1st 3 months
foetal after 3 months
alpha thalasaemia most common in which countries
south east asia
beta thalasaemia most common in which countries
south europe and middle east
what is pathology in thalasaemia due to
imbalance between alpha and beta resulting in homotetramers
alpha and beta usually due to what types of mutations
alpha - large deletions
beta - point mutations
untreated B thalassaemia leads to
hepatosplenomegaly
bone marrow expansion
increased iron absorption - HF, liver cirrhosis
type of anaemia in B thalassaemia
microcytic, hypochromic, tear shapes
treatment for B thalassaemia
blood transfusion every 3 weeks and chelation therapy
south east Asian vs mediterranian alpha thalassaemia mutaiton
what is significance
asian is alpha alpha/ –
mediterranian is alpha - /alpha -
significance is if asian mutation - 1/4 chance of having –/–
what is a compound heterozygote
individuals with 2 different allele mutations e.g. alpha and sickle cell
double heterozygote
alpha globin and beta globin mutations
what do you need for a good CXR (6)
full inspiration
PA - heart closer to film
hug machine to move scapula out of the way
erect
sternal notch in line with spinous processes
7 anterior ribs
