Title: Disorders of Development Congenital Birth Defects Congenital Teratogenic Agents Trisomy Disorders Wi
1Disorders of DevelopmentCongenital Birth
DefectsCongenital Teratogenic AgentsTrisomy
DisordersWilliams Syndrome Autism
2- Birth Defects occur during Critical Periods in
Development - 1. Defects during Zygote are aborted
- 2. Defects in the remaining prenatal period are
irreversible - 3. Critical Periods a time of rapid change in
the development of the organism (i.e., system or
structure) and if interrupted will result in
permanent congenital abnormalities.
3- Sensitive periods in development
- 1. Occur prenatally and less irreversible
- 2. Interference will disrupt growth may result
in subtle dysfunctions - 3. Continues into post-natal period
- Teratogens
- - Agents that cause congenital malformations in
critical periods, and subtle alterations in the
brain during sensitive periods
4(No Transcript)
5Critical Period Defect Cleft Palate
- Irreversible congenital abnormality affecting a
critical period (palate development) during the
embryonic and early fetal stages - May affect pituitary growth as the palate and
anterior pituitary are derived from the same
embryonic tissue.
6Critical Period Defect Anencephaly (absence of
brain)
Failure for the brain to grow beyond the
rhombencephalon. Neonate failed to survive.
7Critical Period Defect Schizencephaly Development
al of the brain affected during the fetal period
(i.e., growth of the forebrain). Cells either
failed to migrate or ventricular region failed to
close.
8Teratogens Agents that cause congenital
malformations
9Fetal Alcohol Syndrome
Features Growth retardation, neurodevelopmental
abnormalities (fine motor skills, LD, behavior
disorders, and mental retardation in 50).
Facial dysmorphia during embryonic period (week
4-8), CNS problems during the fetal period
(migration problems, smaller dendrites, few
neurons in brain regions)
10Genetic Conditions Chromosomal Abnormalities
- Trisomy 21 (Downs Syndrome)
- Trisomy of other chromosomes
- Edwards Syndrome (Trisomy 18)
- Pataus Syndrome (Trisomy 13)
11Trisomy 21 Downs Syndrome
Non-disjunction of the 21st Chromosome
12Anatomical Dysmorphia Risk (Increase with
Maternal Age)
Just 1-20 graphed here
13How does Trisomy 21 happen? First, normal
development In normal development mitosis
proceeds normally from the first cell division
14In Downs Syndrome, non-disjunction of the 21st
chromosome can happen at the first cell division
15Non-disjunction of the 21st chromosome cab occur
after the first cell division resulting in a
mosaic form of Downs Syndrome
16Faulty distribution can occur in the egg or
sperm when the mother or father is a carrier.
17Trisomy 18 Edwards Syndrome
18Some Features of Edwards Syndrome
- Cardiovascular problems
- Gastrointestinal and genitourinary problems
- Life Span death by 12-24 months (very few reach
adulthood) - Incidence 0.2/1000 births
- Facial microcephaly, low set malformed ears
- Skeletal webbed neck, overlapping of fingers and
fixed flexion of fingers - CNS severe mental retardation, neural tube
defect, ocular abnormalities - Respiratory apnea
19Trisomy 13 Pataus Syndrome
- Features
- 0.1/1000 births
- Spina bifida cleft palate
- CNS underdevelopment of frontal lobe (fails to
divide) and corpus callosum - Profound Mental Retardation
- Extra fingers and toes, deaf
- Life Span 82 die in the first month, 5-10 die
in first year.
20Williams Syndrome Partial Deletion of the 7th
Chromosome
- Features
- 1 in 20,000 births
- Neurodevelopmental delays, cognitive deficits,
LD, ADHD - Overly friendly, social
- Extremely empathic
- Low muscle tone
- Extremely sensitive hearing
21Brain Areas Affected Amygdala activates more for
threatening scenes and very little for
threatening faces. This accounts for absence of
anxiety in interpersonal interactions (no fear,
hence over friendliness). Also, abnormal activity
in frontal lobe and a disconnect with the
amygdala (except for medial-prefrontal which is
linked to empathy and the only structure still
connected to the amygdala)
Normal Control Williams Syndrome
Amygdala
22Elastin protein, made only during the prenatal
period, is absent and causes vascular problems
during life the missing elastin gene is use to
identify the 21 missing genes in Williams
Syndrome.
Genetic Abnormality of Chromosome 7 21 genes
missing
23Autism
- A neurodegenerative disorder characterized by
impairment in social interaction and
communication. - Age of onset typically between ages 2 and 4
(sometimes earlier)
24Symptoms
25Theories for Etiology and CNS Problems
- Genetic alterations
- Prenatal exposure to toxins and/or viruses
- Maternal and fetal immune interactions
- Vaccination with mercury base
- Amygdala less active and area is smaller
- Hippocampus is smaller
- Frontal areas (medial prefrontal region) less
active - Less activity in the superior temporal sulcus
(involved in understanding others) - Larger heavier brain suggests apoptosis failure
26Microglia Activation in Autism (white matter of
the cerebellum)
Microglial cells
27Brain Areas Affected in Autism Fusiform Face
Area (FFA), Amygdala, Left Frontal Lobe, Left
Temporal Lobe, and Cerebellum
28References for Photos (slides 5,6,9,11,16,18,19,2
2-25)
- http//images.google.com/imgres?imgurlhttp//www.
hallym.or.kr/kdcp/cytogenetics/cytogen-ds.files/c
6_cleft_lip.jpgimgrefurlhttp//www.hallym.or.kr/
kdcp/cytogenetics/cytogen-ds.htmh483w316sz6
1tbnid9z1GFXy5kykJtbnh126tbnw82hlenstart
61prev/images3Fq3DWilliams2BSyndrome26start
3D6026svnum3D1026hl3Den26lr3D26client3Dfi
refox-a26rls3Dorg.mozillaen-USofficial_s26sa
3DN - http//images.google.com/imgres?imgurlhttp//cas.
bellarmine.edu/tietjen/HumanBioogy/Finished2520Im
ages/gen12.gifimgrefurlhttp//cas.bellarmine.edu
/tietjen/HumanBioogy/bills_developmental_abnormali
ties.htmh383w400sz117tbnidKbFuC4QsI4sJtb
nh114tbnw120hlenstart3prev/images3Fq3DE
dward2527s2BSyndrome26svnum3D1026hl3Den26lr
3D26client3Dfirefox-a26rls3Dorg.mozillaen-US
official_s26sa3DG - http//images.google.com/imgres?imgurlhttp//www.
cmu.edu/cmnews/extra/extra_art/Just_Fig1.jpgimgre
furlhttp//www.cmu.edu/cmnews/extra/extra_art/h
421w150sz25tbnid0aXX65rnVysJtbnh122tbnw
43hlenstart189prev/images3Fq3Dautism2Bbra
in26start3D18026svnum3D1026hl3Den26lr3D26
client3Dfirefox-a26rls3Dorg.mozillaen-USoffic
ial26sa3DN -
- http//www.altcorp.com/DentalInformation/autismcyt
okines.htm -
- http//www.neuro.jhmi.edu/neuroimmunopath/Microgli
a20pictures/5_lg.jpg
http//images.google.com/imgres?imgurlhttp//www.
fetalalcohol.com/images/face-thm.gifimgrefurlhtt
p//www.fetalalcohol.com/what-is-fase.htmh260w
304sz16tbnidRpmOv4g5G04Jtbnh95tbnw112hl
enstart6prev/images3Fq3DFetal2BAlcohol2BSy
ndrome26svnum3D1026hl3Den26lr3D26client3Df
irefox-a26rls3Dorg.mozillaen-USofficial_s26sa
3DG http//images.google.com/imgres?imgurlhtt
p//www.infobiogen.fr/services/chromcancer/IntroIt
ems/Images/tri21FaceEng.gifimgrefurlhttp//www.i
nfobiogen.fr/services/chromcancer/IntroItems/PolyT
ri21Eng.htmlh429w463sz50tbnidXGXbYU9uVcYJ
tbnh115tbnw125hlenstart1prev/images3Fq
3DTrisomy2B212Bface26svnum3D1026hl3Den26lr
3D26client3Dfirefox-a26rls3Dorg.mozillaen-US
official_s26sa3DG