Home What is it?

What is it?

by Summerly Rowlands

What is 22q11.2 deletion syndrome?

22q11.2 deletion syndrome is a rare genetic disorder, second most common to Down Syndrome. It seems odd to have the words ‘rare’ and ‘common’ describing the same thing, but think of it like this — in the world as a whole, genetic disorders are rare, but in the world of genetic disorders, 22q11.2 deletion syndrome is more common than we think or even know.

About 1 in 4,000 people are diagnosed with 22q11.2 deletion syndrome, though the medical experts believe this number to be even higher due to people living their life with this syndrome unknowingly.

In those diagnosed with 22q11.2 deletion syndrome (or as we will refer to it, 22q or 22q11, not to be mistaken for 22q11.2 duplication syndrome), a tiny piece of chromosome 22 is missing. That missing piece is known as “11.2” and is located on the “q arm” of the 22nd chromosome (*ScIeNcE*). This can cause an extremely wide spectrum of health problems ranging from mild to life-threatening. There can also be certain physical features, noticeable or unnoticeable, in one’s facial structure and/or stature. While this disorder is lifelong and has no cure, many of the issues can be treated, especially if found early.

*ScIeNcE* — Chromosomes carry the genetic information for each individual. Human body cells normally have 46 chromosomes. There are 22 pairs of chromosomes numbered from 1 through 22 (largest to smallest) and then the 23rd pair is the sex chromosome designated X and Y (XY male, XX female). Each chromosome has a short arm termed “p” and a long arm termed “q”. Chromosomes are then further divided into many bands that are numbered. Therefore, 22q11.2 refers to band 11.2 on the long arm of the 22nd chromosome.