What does chromosome pq mean?

T stands for translocation, the abbreviation of translocation, P stands for chromosome short arm and Q stands for chromosome long arm. t( 1； 3)(q25； Q 12) indicates that the long arm 2 region 5 of chromosome 1 has been translocated with the long arm 1 region 2 of chromosome 3.

The change of chromosome fragment position is called translocation (T). With the change of gene position. Translocation is called translocation or intra-chromosomal translocation when it occurs on one chromosome, and it is called inter-chromosomal translocation when it occurs between two homologous or non-homologous chromosomes.

The translocation of homologous chromosomes mainly occurs on chromosomes 10 and 14, and chromosome arm is the structural name of chromosomes in its nucleus. In the metaphase of cell division, each chromosome contains two chromatids, called sister chromatids.

The two monomers are connected to each other at the centromere, and the centromere narrows, so it is also called the main constriction. The part from centromere to both ends of chromosome is called chromosome arm. If the centromere is not in the center of the chromosome, it can be divided into long arm (Q) and short arm (P).

Extended data:

International rules for naming human chromosomes

1, chromosome number: 1 ~ 22 chromosomes or XY.

2. Number of arms of chromosome: long arm Q or short arm P ..

3. Serial number of the region: "Region" is the region between two adjacent landmarks on the chromosome arm ("landmark" is a constant band with significant morphological characteristics on the chromosome, including the ends of two arms, centromeres and some significant bands on the arm). The serial number of this area is numbered from centromere to the distal end of both arms.

4. Serial number of the band: "Band" is a horizontal stripe with different widths and alternating light and dark on the chromosome. The serial number of the belt is numbered from the centromere side to the far end of the arm, and the belt as a landmark belongs to the 1 belt in the far area of the landmark.

5. Subbands and serial numbers of subbands: subbands and subbands are subdivided step by step on the basis of bands. Subbands are written after the band number, separated by decimal points, and the numbering principle is also from the near side of centromere to the far side, and the subbands are written directly after the subbands without punctuation. For example, 1q42. 13 indicates that the long arm of chromosome 1 has two bands, and 1 has three subbands.

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