Genetics Flashcards
different DNA analysis is used depending on on the size of the mutation, what methods are used in order or largest to smallest mutation?
chromosome analysis
array comparitive genomic hybridization (for deletions/duplications/translocations)
PCR and sanger sequencing
next generation sequencing
stop codon?
UAG
when is US done in normal pregnancy?
booking = 12 weeks
detailed scan = 20 weeks (anomaly scan)
when are US scans done for specific anomalies?
cardiac = 10-12 weeks
microcephaly = after 22 weeks
short limbs = after 22 weeks
what is considered after a referral from GP concerning anomalies on US scan?
is there a family history?
what happened in pregnancy?
how severe are scan findings?
is there a identifiable genetic cause?
how is duchenne muscular dystrophy inherited?
X linked recessive
how can DNA be tested in pregnancy?
usually PCR based (gives results in 2-3 days)
occasionally southern blotting is done (results in 2-3 weeks)
CVS (can be done from 11.5 weeks)
amniocentesis (can be done from 16 weeks)
when and how can sex be determined and how can this be helpful?
free foetal DNA can be used to determine sex from 8 weeks
can exclude chance of diseases only seen in once gender (e.g muscular dystrophy)
what is PGD?
pre-implantation genetic diagnosis
where a genetic test is done on an embryo before re-implanting the best one into the uterus
who liscences pgd?
HFEA
how is PGD done?
basically same procedure as IVF and all associated risks
FISH used to locate chromosomes
