Chromosomal deletion syndromes occur when part of a chromosome is missing.
(See also Overview of Chromosome and Gene Disorders.)
Chromosomes are structures within cells that contain DNA and many genes.
Genes are segments of deoxyribonucleic acid (DNA) and contain the code for a specific protein that functions in one or more types of cells in the body. Genes contain instructions that determine how the body is supposed to look and function. (See Genes and Chromosomes for a discussion about genetics.)
When parts of chromosomes are missing, a number of syndromes can occur. These syndromes are called chromosomal deletion syndromes. They tend to cause birth defects, intellectual disability, and problems with physical development. In some cases, defects can be severe, and affected children may die before birth or during infancy or childhood.
There are many chromosomal deletion syndromes, which include
Chromosomal deletion syndromes may be suspected before birth or after birth. The diagnosis of these syndromes is confirmed by chromosomal testing. (See also Next-generation sequencing technologies.)
Some physical defects can be corrected with surgery, but generally treatment is supportive.