Congenital anomalies Flashcards
if teratogen is introduced within first two weeks of blastocyst what happens
death
what is most sensitive time for teratogan affect
organogenesis
what is especially prone to congenital anomolies
ears
if you see malformed ear what will you look for
major congenital anomalies
what are three grouping of teratogans
infectious agents
physical agents
chemical agents
what is multifactoral inheritance
combination of genetic & environmental factors
what is deormation
alteration of portion of body due to mechanical force
how is club feet deformation
compression fo amniotic cavity forms club feet
are teratogens responsible for most congenital anomalies
no
are polygenetic effects involved in multifactorial inheritance
yes
why are minor congenital anomalies important?
they can be associated with major ones
What is the leading cause of infant mortality
congenital anomalies
What is the difference b/w syndrome & association?
syndrome is a group of anomalies that has known cause (like fetal alcochol syndrome)
association anomalies together but the cause is unknown
What are the 4 families of congenital anomalies?
- Chromosomal aberrations- changes in
chromosomal numbers/ groupings. Ex- trisomy 18 - Mutant genes- microdeletions. Ex-Prader Willi
- Environmental agents. Ex- Teratogens
- Multifactorial inheritance- combination of genetic (polygenetic) and environmental factors (teratogens) that runs in families
what is the only monosomy anomaly compatible with life?
45X (Turner Syndrome)
What are most chromosomal (numerical) anomalies due to?
meiotic nondisjunction
What is trisomy 21?
down syndrome - extra chromosome 21
What is tirsomy 18?
Edwards syndrome - extra chromosome 18
What is trisomy 13?
Patau syndrome - extra chromosome 13
what is klinefelter syndrome?
47XXY or 48XXXY
often mental retardation
What is turner syndrome?
45, XO
only monosomy compatible with life
Edwards, patau, klinefelter, etc are all examples of what?
numerical chromosomal aberrations
Angelman syndrome has chromosome microdeletion, how is it inherited?
maternal chromosome
prader-willi syndrome has chromosome microdeletion, how is it inherited?
paternal chromosome
Cri-du-chat, prader-willi, and angelman are all examples of what?
structural chromosomal aberrations
teratogen is an example of a _____ agent
envrionmental
teratogen can only cause affect after certain what?
threshold level of exposure has been reached
when is most important to not be exposed to teratogens?
first trimester, especially during weeks 2-8 organgenesis!
What are the 4 congenital anomalies affects?
- malformations
- disruptions
- deformation
- dysplasia
what is a malformation?
complete or partial absence of a structure or major alteration of its normal form
what causes malformations?
enviornmental & genetic factors
What is a disruption?
morphological alteration of already formed structures
what causes disruption?
destructive process
what is a deformation
alteration of portion of body, usually involving musculoskeletal
what causes deformation
mechanical force (like club feet)
what is dysplasia?
abnormal organization of cells into tissues resulting in altered structures
