committee 2 Flashcards
Whats the importance of crossing over of genes?
increase genetic variation
what is the type of inheritance in AD diseases?
Vertical
when looking at pedigrees,we sometimes see a skipped generation.why?
1) reduced penetrance
2) fresh mutation
3) expressed variability
two ways AR diseases differ from AD diseases
no reduced penetrance and expressed variability
what do you mean by neonatal?
once born till 1 month
4 extra AD diseases to know
chronic glaucoma hypertension progeria' huntingtons disease hereditory edema
pattern of inheritance in AR diseases
horizontal
what are factors increasing frequency of AR diseases
1)consanguinity
2)marriage in isolated pop or from same ethnic groups
cause these 2 help decrease gene pool
what is azoospermia and in which disease do we see it?
absence of sperms in semen and its seen in cystic fibrosis
4 extra AR diseases to know
1) galactosemia
2) sickle cell anemia
3) congenital deafness
4) tay sachs disease
a benefit of males having Y instead of X
if they got the affecting X chromosomes they might show less syptoms
when does lyonization occurs?
early development (1-2 weeks after conception)
mechanism of lyonization,X inactivation
DNA methylation
what gene controls x inactivation?
XIST gene on XiC (x inactivation center)
2 types of lyonization
1) typical:irreversible and X chromosome chosen randomly
2) atypical:not randomly chosen,reversible,can be translocation or structural abnormality
what is mosaicism?
having cells with different genotypes in same body
Are there genes on X chromosome that escape inactivation?
pseudoautosomal genes ,,mainly found on p arm
what is the biggest gene in our genome?
dystrophin
what is the pattern in x linked dominant diseases?
vertical
whats the name of genes on y chromosome?
holandric genes which are responsible for male characteristics
what cells are rich in Mt?
muscles and neurons
thats why neuromuscular systems are more affected by mutations in mtDNA
what do the 37 genes in mtDNA code for?
muscles and neurons
thats why neuromuscular systems are more affected by mutations in mtDNA
3 types of mtDNA mutations
OXPHOS=oxidative phosphorilation
1- Missense mutations in genes of OXPHOS proteins*
2- Point mutations of tRNA and rRNA genes,*
3- Rearrangements causing deletions and
duplications in mtDNA molecules.*
