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