Download Examples of aneuplody in humans

Examples of aneuplody in humans
Trisomy 21
Down’s Syndrome
47,XX,+21
47,XY,+21
1/660 to 1/800 live births
3% – 4% due to translocation
2% - 4% mosaic trisomy 21 (error in mitotic division)
Down syndrome is a chromosomal condition that is associated with mental
retardation, a characteristic facial appearance, and weak muscle tone
(hypotonia) in infancy. People with Down syndrome are at an increased risk of
heart defects, digestive problems such as gastroesophageal reflux, hearing
loss, and other medical problems.
Most cases of Down syndrome result from trisomy 21. A small percentage of
cases occur when only some of the body's cells have an extra copy of the
chromosome. These cases are called mosaic Down syndrome.
Down syndrome can also occur when part of chromosome 21 becomes
attached (translocated) to another chromosome before or at conception,
although this is uncommon. Affected people have two copies of
chromosome 21, plus extra material from chromosome 21 attached to
another chromosome. These cases are called translocation Down syndrome.
Trisomy 13
1/5000 to 1/10,000 live births
•
Trisomy 13 is associated with multiple abnormalities, including severe mental
defects and defects of the brain that lead to seizures (hypsarrhythmia),
apnea, deafness, and ocular (relating to the eye) abnormalities.
•
•
•
•
•
Patau Syndrome
Bartholin-Patau
syndrome
Chromosomal
imbalance syndrome,
pair 13, trisomy
chromosome 13 trisomy
syndrome
D1 Trisomy
Trisomy 13 syndrome
The eyes are small with defects in the iris (coloboma). Most infants have a cleft
lip and cleft palate, and low-set ears. Congenital heart disease is present in
approximately 80% of affected infants. Hernias and genital abnormalities are
common.
http://www.nlm.nih.gov/medlineplus/ency/article/001660.htm
Most cases of Patau syndrome result from trisomy 13.
A small percentage of cases occur when only some of the body's cells have
an extra copy of chromosome 13, resulting in a mixed population of cells with
a differing number of chromosomes. Such cases are sometimes called mosaic
Patau syndrome.
Patau syndrome can also occur when part of chromosome 13 becomes
attached to another chromosome (translocated) before or at conception.
http://ghr.nlm.nih.gov/condition=patausyndrome
Trisomy 18
•
•
•
•
•
•
•
•
•
Edward’s Syndrome
Chromosomal
imbalance syndrome,
pair 18, trisomy
Complete trisomy 18
syndrome
E3 Trisomy
Edward's Syndrome
Trisomy 16-18
Trisomy E syndrome
Trisomy 18 syndrome
1/3,000 to 1/6,000 live births
Approximately 80 percent of cases occur in females.
Infants born with Edwards syndrome have an extremely high mortality rate—
only 5 to 10 percent of these infants survive the first year of life. Some
characteristics of this condition are low birth weight; a small, abnormally
shaped head; small jaw; small mouth; and clenched fists with overlapping
fingers. Infants born with Edwards syndrome also have mental retardation,
heart defects, and other organ malformations such that most systems of the
body are affected.
Most cases of Edwards syndrome result from trisomy 18.
A small percentage of cases occur when only some of the body's cells have
an extra copy of chromosome 18, resulting in a mixed population of cells with
a differing number of chromosomes. Such cases are sometimes called mosaic
Edwards syndrome.
Very rarely, a piece of chromosome 18 becomes attached to another
chromosome (translocated) before or after conception.
http://ghr.nlm.nih.gov/condition=edwardssyndrome
Triple X syndrome
•
•
•
•
•
•
Trisomy X
47, XXX
Triplo X syndrome
Trisomy X
47,XXX
XXX syndrome
1/1,000 to 1/1,500 live female births
Triple X syndrome, also called trisomy X or 47,XXX, is characterized by the
presence of one extra X chromosome in each of a female's cells. Most often,
this chromosomal change causes no unusual physical features or medical
problems. Females with triple X syndrome are sometimes taller than average
and have an increased risk of learning disabilities and delayed speech and
language skills. These characteristics vary widely among affected girls and
women, however. Most females with triple X syndrome have normal sexual
development and are able to conceive children.
Triple X syndrome results from an extra copy of the X chromosome in each of
a female's cells. Researchers are not yet certain why an extra copy of the X
chromosome is associated with tall stature and learning problems in some girls
and women.
Some females with triple X syndrome have an extra X chromosome in only
some of their cells. These cases are called 46,XX/47,XXX mosaics.
http://ghr.nlm.nih.gov/condition=triplexsyndrome
Klinefelter Syndrome
•
•
•
•
Klinefelter's Syndrome
47,XXY
XXY syndrome
XXY trisomy
1/500 to 1/2,000 live male births
Klinefelter syndrome is a chromosomal condition that affects male sexual
development. Some males with the condition have low levels of the hormone
testosterone beginning during puberty, which can lead to breast
development (gynecomastia) and an increased risk of breast cancer,
reduced facial and body hair, and an inability to father children (infertility).
Boys with Klinefelter syndrome may also have difficulty with speech and
language development.
Klinefelter syndrome is caused by the presence of one or more extra copies of
the X chromosome in a male's cells. Extra copies of genes on the X
chromosome interfere with male sexual development, preventing the testicles
from functioning normally and reducing the levels of testosterone.
Most often, males with Klinefelter syndrome have two X chromosomes and
one Y chromosome (XXY). Some males with Klinefelter syndrome have the
extra X chromosome in only some of their cells; these cases are called mosaic
XY/XXY.
http://ghr.nlm.nih.gov/condition=klinefeltersyndrome
47, XYY syndrome
•
•
•
XYY Karyotype
XYY syndrome
YY syndrome
1/1,000 live male births
Most often, this chromosomal change causes no unusual physical features or
medical problems. Males with 47,XYY syndrome are sometimes taller than
average and have an increased risk of learning disabilities and delayed
speech and language skills. These characteristics vary widely among affected
boys and men, however. Most males with 47,XYY syndrome have normal
sexual development and are able to conceive children.
47,XYY syndrome is caused by the presence of a single extra copy of the Y
chromosome in each of a male's cells. Researchers are not yet certain why an
extra copy of the Y chromosome is associated with tall stature and learning
problems in some boys and men.
Some males with 47,XYY syndrome have an extra Y chromosome in only some
of their cells. These cases are called 46,XY/47,XYY mosaics.
http://ghr.nlm.nih.gov/condition=47xyysyndrome
Turner syndrome
•
•
•
•
•
•
Bonnevie-Ullrich
Syndrome
monosomy X
TS
Turner's Syndrome
Ullrich-Turner syndrome
45,X
1/2,500 live female births
Women with this condition tend to be shorter than average and are usually
infertile, or unable to conceive a child, because of a loss of ovarian function.
Other features of Turner syndrome vary among affected females and can
include webbing of the neck, puffiness or swelling (lymphedema) of the
hands and feet, skeletal abnormalities, heart defects, and kidney problems.
Turner syndrome results when a female's cells have one normal X
chromosome and the other sex chromosome is missing or altered. The missing
genetic material affects development and causes the characteristic features
of the condition.
About half of individuals with Turner syndrome have monosomy X, which
means each cell in a woman's body has only one copy of the X chromosome
instead of the usual two copies. Turner syndrome can also occur if one of the
sex chromosomes is partially missing or rearranged rather than completely
missing. Some women with Turner syndrome have a chromosomal change in
only some of their cells, which is known as X-chromosome mosaicism.
Researchers have not yet determined which genes on the X chromosome are
responsible for most signs and symptoms of Turner syndrome. They have,
however, identified one gene called SHOX that is important for bone
development and growth. Missing one copy of this gene likely causes short
stature and skeletal abnormalities in women with Turner syndrome.
http://ghr.nlm.nih.gov/condition=turnersyndrome