Acute lymphoblastic leukemia (ALL), also known as acute lymphocytic leukemia, is a subtype of acute leukemia, a cancer of the white blood cells. Somatically acquired mutations in several genes have been identified in ALL lymphoblasts, cells in the early stages of differentiation. Germline variation in certain genes may also predispose to susceptibility to ALL (Trevino et al., 2009). Genetic Heterogeneity of Acute Lymphoblastic Leukemia A susceptibility locus for acute lymphoblastic leukemia (ALL1) has been mapped to chromosome 10q21. See also ALL2 (613067), which has been mapped to chromosome 7p12.2; and ALL3 (615545), which is caused by mutation in the PAX5 gene (167414) on chromosome 9p.

An abnormal reduction in numbers of all blood cell types (red blood cells, white blood cells, and platelets).

Increased susceptibility to viral infections, as manifested by recurrent episodes of viral infection.

Increased susceptibility to bacterial infections, as manifested by recurrent episodes of bacterial infection.

Increased susceptibility to fungal infections, as manifested by multiple episodes of fungal infection.

An abnormal decrease from the normal count of B cells.

A group of phenotypically heterogeneous genetic disorders characterized by profound deficiencies of T- and B-cell function, which predispose the patients to both infectious and noninfectious complications.

An abnormally decreased level of immunoglobulin in blood.

An intrauterine state characterized by suboptimal values in the fetal heart rate, oxygenation of fetal blood, or other parameters indicative of compromise of the fetus. Signs of fetal distress include repetitive variable decelerations, fetal tachycardia or bradycardia, late decelerations, or low biophysical profile.

The presence of excess amniotic fluid in the uterus during pregnancy.