Chromosome 19
19p13.13 deletion syndrome results from the deletion of a small part of the short arm (p) of chromosome 19 in each cell. The main features of the 19p13.13 deletion syndrome include an unusually large head size (macrocephaly), tall stature, delayed speech and motor skills development and intellectual disability that is generally of moderate severity. Seizures, feeding and digestive difficulties and eye abnormalities are also common.
People with this condition are missing 300 Kb to 8 Mb (3 million DNA building blocks) in the short arm of chromosome 19. The elimination region is generally referred to as p13.13. The exact size of the elimination varies among affected individuals, but it is believed to include at least 16 genes. This removal affects one of two copies of chromosome 19 in each cell.
Cancer. Changes on chromosome 19 have been identified in several types of cancer. These mutations are somatic, which means that they are acquired in the course of life and are only present in the cells that give rise to cancer. Genetic material rearrangements have been found between chromosome 19 and one of several chromosomes in some forms of blood cancer (leukemia). These rearrangements, called translocations, seem to be particularly common in a type of leukemia called Acute lymphoblastic leukemia (ALL). These translocations probably alter genes that are critical for keeping cell growth and division under control. Unregulated cell division can lead to the development of cancer.
Other changes in the number or structure of chromosome 19 can have a variety of effects on growth and development. These chromosomal changes can cause developmental delay, intellectual disability, feeding difficulties, hearing and visual impairment, heart problems or other congenital defects. The signs and symptoms that occur in a particular individual depend on the specific chromosomal change and what genes are involved.
