Description of the Chromosome

When we want to describe the location of some structural abnormality we used special marks. We have to count the regions always from the centromere - for both arms.

Example: 1q13



 * the first number is the number of chromosome - chromosome 1
 * (p) and (q) are used for the marking of arm - (p) for small arm and (q) for long arm - the long arm
 * the third number is for the region of chromosome - region 1
 * last number is for the band - band 3

So the change is located on the long arm of chromosome 1 (see Fig. Chromosomal marking).

Related articles

 * Chromosome abnormalities