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 (