Overview of Chromosome and Gene Disorders. Clinical indications that should raise suspicions of a sex chromosome abnormality are:. In somatic cells in normal females but not in normal males what are two examples of sex chromosome disorders in Victorville, one X chromosome is inactivated early in development, thus equalizing the expression of X-linked genes in the 2 sexes.
Between andKlinefelter went for one year to Boston to work at the Massachusetts General Hospital. In a few individuals, there is slight mental retardation.
The Manual was first published as the Merck Manual in as a service to the community. Down syndrome is a well-known example of a numerical disorder three copies of chromosome Klinefelter syndrome males with more than two X chromosomes usually have extreme symptoms and are often slightly retarded mentally.
The two extra copies are due to an abnormal triplication of the synuclein gene on one chromosome. Except for certain cells for example, sperm and egg cells or red blood cells , every human cell contains 23 pairs of chromosomes, for a total of 46 chromosomes.