what is rubella what is the risk and at what trimester
respiratory desiease caused by virus. fever and rash for 2-3 days. if exposed to fetus they develop a congenital rubella syndrome (CRS). results in slide 3. risk as high as 85% in 1st trimester. after week 18 little risk of defects.
what is thalidomide, when is it highly teratogenic, what does it inihibit, what does it cause
Highly teratogenic during days 25-50. inihibits angiogenesis. gross malformations of limbs, facial and systemic abnormalities.
what are some ways that malformations can happen
slide 6/7
what is syndactyly
a malformation where the tussies between toes fail to breakdown
what is polydactyly
extra fingers and toes
what is the prevalence of brith defects
2-4% at birh doubling after a few years
what are the causes and some other types of birth defects and fatal rate
ranges from enzyme deficiencies SNP in DNA to very complex gross anatomical abnormalities. 25 % fatal raate. interaction between genetic and environmental factors.
what are teratogens
slide 9
what are the factors that govern the capacity of an agent to produce birth defects
slide 11
what is the susceptibility during the first 3 weeks
unlikely to lead to defective development, will either kill embryo or will be compensated for.
what is the suceptibility during weeks 3 to 8
maximal susceptibiltity as this is when most major organs and body regiors are being established.
what are the anomalies from 3rd to 9th month
tend to be functional anamolies like intelectual disability or involve distubrance is growth of formed parts.
what is special about the timeline of effects on brain and behavior
vulnerability from 1st trimester through adolescence. the nuerotoxins can be more subtle
what was anticonvulsants for?
prescribed to control siezure disorders. with many nueral, facial and liver abnormalities.
what did the mercury contamination result in
intelectual disability and other CNS impairments, came from bioaccumulation in food chain.
what can alcohol do as a teratogen
prevalacne of 0.2-0.7 % results in growth dificiency, facial dysmorphogenesis and CNS effecs, leading cause of intellectual disability.
what s the problem with ilegal drugs in the fetus
easily cross through the placenta, accumulate more in the fetus, causes IQ reduction, atention problems, behavioural problems as a result of alterations in dopamine system and brain structre.
whats the most common class of birth defects and whats the percentage
congenital heart defects, with 30% of infants.
what are the defects and some of the causes to congenital heart defects
slide 20
what aare some examples of congenital disorders caused by chromosomal aberrations
anuploidy, structural errors - reciprical translocations, deletions, duplications , breakages caused by environmental factors, such as radioation and chemical teratogens.
what are the 3 congenital disorders caused by genetic mutations
autosomal dominant, autosomal recessive, x-linked recessive
what is autosomal dominant
a genetic mutation that causes achondroplasia - short-limbed dwarfism and apert’s syndrome - cranio-facial abnormalities
what is autosomal recessve
a genetic mutation that causes sikle cell anemia - mutation in hemoglobin gene
congenital phocomelia - limb deformities
whats x - lnkined recessive
a genetic mutation causing congenital disorders in the form of hemophilia - blood cloting disorder, AIS - Androgen insensitivity.
