Chromosome Abnormalities
ANEUPLOIDY
Karyotype Charts
• 1 single Y chromosome is a sufficient to
produce maleness while its absence is
necessary for femaleness……
Down Syndrome
• Trisomy 21
• Often Down syndrome
is associated with
poor physical
development and
mental retardation,
people with Down
syndrome have
features characteristic
feature of the disease
has been nimita and
mongolism.
• When meiosis goes wrong
• Errors at meiosis occur more often in the
egg cell as women get older, so the
chances of a couple having a baby with
Down syndrome rises from about one in
1400 in women under the age of 25, to
one in a 100 by age 40.
Turner’s Syndrome
• XO
• 45 chromosomes
• Don’t ovulate, slight mental
retardation, sterile, 4’7” short,
webbed neck, small wide
breasts, broad chest, turned out
elbows
Klinefelter’s XXY
or XXXY XXXXY
• Sterile
• High pitch voice
• Make little
testosterone
• Taller by an inch
• Not homo- but
not interested in
girls…
• Overweight
Gynecomastia
XXX Super-females
•
•
•
•
•
Inch or so taller
Long legs- slim torso
Normal /fertile
Low normal intelligence
1 in 1000
XYY syndrome
•
•
•
•
•
•
•
•
Supermales
Tall above 6 feet
Act normal
Produce HIGH levels of
testosterone
Puberty- slender, severe acne,
poorly coordinated
Fertile
Serial Killers- not true,
But wife beaters? Maybe
Trisomy 18 – Edwards Syndrome
•
•
•
•
•
Mental retardation, seizures
Small head
Small wide set eyes
Heart defects
Clenched hands
Patau Syndrome: Trisomy 13
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Cleft lip or palate
Clenched hands (with outer fingers on top of the inner fingers)
Close-set eyes -- eyes may actually fuse together into one
Decreased muscle tone
Extra fingers or toes (polydactyly)
Hernias: umbilical hernia, inguinal hernia
Hole, split, or cleft in the iris (coloboma)
Low-set ears
Mental retardation, severe
Scalp defects (missing skin)
Seizures
Single palmar crease
Skeletal (limb) abnormalities
Small eyes
Small head (microcephaly)
Small lower jaw (micrognathia)
Undescended testicle (cryptorchidism)
• More than 80% die in the first month
3 years old
key
color
Summary
significance
lethal
normal female phenotype
normal male phenotype
Turner's syndrome (abnormal female)
Klinefelter's syndrome (abnormal male)
Non-autosomal
0
X
XX
XXX
XXXX
XXXXX
0
00
X0
XX
XXX
XXXX
XXXXX
Y
Y0
XY
XXY
XXXY
XXXXY
XXXXXY
YY
YY
XYY
XXYY
XXXYY
XXXXYY
XXXXXYY
YYY
YYY
XYYY
XXYYY
XXXYYY
XXXXYYY
XXXXXYYY
YYYY
YYYY
XYYYY
XXYYYY
XXXYYYY
XXXXYYYY
XXXXXYYYY
YYYYY YYYYY XYYYYY XXYYYYY XXXYYYYY XXXXYYYYY XXXXXYYYYY
key
colo
r
significance
case where complete non-mosaic trisomy can never survive to term
case where complete non-mosaic trisomy can occasionally (barring other
complications) survive to term
case where complete non-mosaic trisomy can always (barring other complications
survive to term
#
monosomy
trisomy
1
Trisomy 1
2
Trisomy 2
3
Trisomy 3
4
Wolf-Hirschhorn syndrome
Trisomy 4
5
Cri du chat
5q deletion syndrome
Trisomy 5
6
7
Trisomy 6
Williams syndrome
Trisomy 7
8
Warkany syndrome 2
9
Trisomy 9
10
Trisomy 10
11
12
Jacobsen syndrome
Trisomy 11
Trisomy 12
13
Patau syndrome
14
Trisomy 14
15
Angelman syndrome
Prader–Willi syndrome
16
Trisomy 15
Trisomy 16
17
Miller-Dieker syndrome
Smith-Magenis syndrome
Trisomy 17
18
18q deletion syndrome
Edwards syndrome
19
Trisomy 19
20
Trisomy 20
21
Down syndrome
22
DiGeorge syndrome
Cat eye syndrome
Trisomy 22