Transcript Chromosomal Disorders - Turner

Genetic Disorders
A Collage of Multiple Syndromes
Syndromes Covered:
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Chromosomal Disorders
Down syndrome (Trisomy 21)
Edward’s syndrome (Trisomy 18)
Patau’s syndrome (Trisomy 13)
Klinefelter’s syndrome (XXY)
Turner syndrome (XO)
Super female syndrome (XXX)
Super male syndrome (XYY)
Cri du Chat (deletion on #5)
Fragile X (duplication on X)
Single Gene Disorders
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Sickle Cell Anemia
Cystic Fibrosis
Huntington’s Disease
Autism (???)
…And, Sex Linked Traits
• Color Blindness
• Hemophilia
Chromosomal Disorders
…are usually caused by an error in cell division
Karyotype!
Down Syndrome=Trisomy 21
A young boy with Down
syndrome
• members.aol.com/InitiativeDo
wn/index.htm
This is what a karyotype
of a girl with downs
syndrome would look
like
www.millerandlevine.co
m/genome/
six.html
Some physical characteristics of individuals with DS…
http://www.infobiogen.fr/services/chromcancer/IntroItems/PolyTri21Eng.html
Edward’s Syndrome=Trisomy 18
Dakota, a young boy
with Edward’s
syndrome
www.childrenofpromise.
net/
dakotaphotos.html
Characteristics of Edward’s Syndrome
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Mental retardation
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Undescended testicles in males
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Prominent back portion of the
head
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Small head (microcephaly)
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Low-set, malformed ears
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Abnormally small jaw
(micrognathia)
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Small mouth
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Cleft lip/Cleft palate
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Growth deficiency
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Upturned nose
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Feeding difficulties
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Narrow eyelid folds (palpebral
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Breathing difficulties
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Developmental delays
fissures)
A karyotype of a male
with Edward’s
syndrome
www.iupui.edu/~marrs/N
100/ch10.html
Patau’s Syndrome=Trisomy 13
Meet Nicholas Wright
the very proud son
of Mark and Jayne
Wright of Hudson,
Illinois USA
Nicholas was born
with Trisomy 13.
www.trisomyonline.org/
wright.htm
Characteristics of Patau’s Syndrome
• Most embryos with trisomy 13 do not survive gestation and are
spontaneously aborted.
• Of those surviving to term gestation, approximately 82-85% do not
survive past 1 month of age, and 85-90% do not survive past 1 year of
age.
• Central Nervous System malformations (no forebrain development)
• long term neurological disability, feeding difficulty, and frequent
pneumonia and other respiratory infections.
• *There have been 5 cases reported in the medical history of patients
living beyond 10 years of age
www.tokyo-med.ac.jp/genet/cki-e.htm
Klinefelter’s Syndrome (XXY)
William John Durfee, a
patient with
Klinefelter’s
syndrome
tiger.towson.edu/~tmcco
r1/durf.htm
Male w/Klinefelter’s
Female w/ Turner
www.anselm.edu/homepage/jpitocch/genbio/geneticsnot.html
k-12.pisd.edu/currInst/science/Genetic/karyo-kline-xxy.htm
Turner Syndrome (XO)
Karen, a patient with
Turner Syndrome
www.geocities.com/ka
re_50273/
aboutturners.html
fig.cox.miami.edu/Faculty/Dana/25001_13.html
sp.uconn.edu/~bi107vc/sp03/terry/division.html
Super Female Syndrome
(Trisomy X)
Females with Trisomy X
are healthy and cannot
be distinguished from
(XX) females excepts
by karyotype (shown)
• http://www.biology.iupui.e
du/biocourses/N100/image
s/XXXFemale.gif
Super Male Syndrome (XYY
Syndrome)
This syndrome is not well characterized
although males that have XYY tend to be
slightly taller than average
Studies have shown that a large number of
men imprisoned are XYY
Other Genetic Disorders…
Cri du Chat (Deletion on part
of #5)
• Characteristics:
• “Cry of the cat," referring to
the distinctive cry of children
with this disorder
• Abnormal larynx
development, which becomes
normal within a few weeks of
birth
• Low birth weight
• Respiratory problems
• Sometimes shortened
lifespan…but usually normal
life expectancy
http://www.findhealer.com/glossary/images/cri
duchat.gif
Fragile X Syndrome: Duplication of a
piece of the X Chromosome
• Most common form of mental
retardation
• Hyperactivity
• Short attention span
• Negative response to touch
• Hand-flapping
• Hand-biting
• Poor eye contact
• Repetition of words/phrases
• Double jointed
• Large or prominent ears
• Large testicles
Single Gene Traits
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Sickle Cell Anemia
Inherited blood disorder
(recessive)
Mostly affects people of
African ancestory
1 in 12 African Americans have
it
Affects hemoglobin (which
carries oxygen in blood) and
makes Red Blood Cells sticky
Interesting correlation between
sickle cell and increased
resistance to malaria
Cystic Fibrosis
• Inherited chronic disease that affects lungs
and digestive system
• Defective gene causes the body to produce
unusually thick, sticky mucus
Huntington’s Disease
• Hereditary brain disorder that diminishes
ability to walk, think, talk, and reason
• Onset usually between the ages of 30-45
Tay-Sachs Disease
• Lipid accumulation in brain cells; mental
deficiency; blindness; death in early
childhood
Autism
• 3 distinctive behaviors that characterize autism:
-difficulties with social interaction
-problems with verbal and nonverbal communication
-repetitive behaviors or narrow, obsessive interests.
• These behaviors can range in impact from mild to
disabling
Sex-Linked Traits
…linked to the sex chromosomes
• Color Blindness
• Hemophilia
• Both are usually found in males only- why??
• Half shaded=carrier; If III-2 and III-3 have a child
(I know...weird), what are the odds of it getting
the “disease”?