what is the comparison of normal and abnormal chroasome (when the abnormal is the alexander disease)
http://ghr.nlm.nih.gov/gene=g
To compare normal and abnormal chromosomes, specifically in the context of Alexander disease, we need to understand the basics of the human chromosome structure and the specific abnormalities associated with this condition.
1. Normal Chromosomes:
In humans, chromosomes are thread-like structures found inside the nucleus of cells. They carry genetic information in the form of genes. Normally, humans have 23 pairs of chromosomes, comprising a total of 46 chromosomes. Each pair is made up of one chromosome inherited from the mother and one from the father.
2. Abnormal Chromosomes in Alexander Disease:
Alexander disease is a rare genetic disorder that affects the central nervous system. This condition is caused by a mutation in the GFAP gene, which provides instructions for making the glial fibrillary acidic protein (GFAP). The mutation leads to an abnormal form of GFAP, resulting in the accumulation of an abnormal protein called Rosenthal fibers.
The specific chromosome involved in Alexander disease is chromosome 17. A duplication mutation occurs in the GFAP gene on chromosome 17, causing an extra copy of the gene to be present. This extra gene copy leads to an excess production of abnormal GFAP protein, resulting in the characteristic features of Alexander disease.
To identify this abnormality, genetic testing such as karyotyping or DNA sequencing is needed. In karyotyping, cells are stained and analyzed to examine the structure and number of chromosomes, including chromosome 17. DNA sequencing, on the other hand, directly analyzes the genetic material to identify mutations in the GFAP gene.
In summary, in the context of Alexander disease, the comparison between normal and abnormal chromosomes involves analyzing the structure and number of chromosomes with a focus on chromosome 17 and identifying specific mutations in the GFAP gene using techniques like karyotyping or DNA sequencing.