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Abnormal numbers of autosomes Metaphase chromosomes are photographed; the chromosome pictures are then enlarged and arranged in pairs by a computer according to length and location of the centromere.
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Diseases and karyotypes
Definitions Autosomes- any chromosome that is not a sex chromosome.
Not the X or Y Sex-linked- genes located on the sex chromosome.
Usually on the X Nondisjunction- A chromosome mishap in meiosis
Abnormal numbers of autosomes
Metaphase chromosomes are photographed; the chromosome pictures are
then enlarged and arranged in pairs by a computer according to
length and location of the centromere. Abnormal numbers of
autosomes
This chart of chromosome pairs is called a karyotype, and it is
valuable in identifying unusual chromosome numbers in cells. A
Karyotype is a photograph of the chromosomes of a single cell.
Another view Normal Female Normal Male ? Colchicine added to cells
Microscope zooms in Cells broken open
Picture of chromosomes taken Chromosomes cut up and arranged
Chromosomal Disorders
Individuals are missing a chromosome or have an extra chromosome
Down syndrome: Trisomy 21
Down syndrome is the only autosomal trisomy in which affected
individuals survive to adulthood. It occurs in about one in 700
live births. Down syndrome: Trisomy 21
Down syndrome is a group of symptoms that results from trisomy of
chromosome 21. Individuals who have Down syndrome have at least
some degree of mental retardation. The incidence of Down syndrome
births is higher in older mothers, especially those over 40.
Chromosome 21 Down's Syndrome Abnormal numbers of sex
chromosomes
Many abnormalities in the number of sex chromosomes are known to
exist. An X chromosome may be missing (designated as XO) or there
may be an extra one (XXX or XXY).There may also be an extra Y
chromosome (XYY). Klinefelters Syndrome XXY Klinefelter's Poor
beard growth Tend to grow fewer chest hairs
Breast development Wide hips Long legs Narrow shoulders
Klinefelter's Karyotype of a male with Klinefelters syndrome Short
(