Fanconi anemia

Fanconi anemia is a condition that is characterized by bone marrow failure, physical differences, organ problems, and an increased risk of certain cancers.

Approximately 90 percent of people with Fanconi anemia have impaired bone marrow function. Bone marrow primarily produces new blood cells. These include red blood cells, which carry oxygen to the body's tissues; white blood cells, which fight infections; and platelets, which are necessary for normal blood clotting. In people with Fanconi anemia, impaired bone marrow function leads to a decrease in the production of all blood cells (aplastic anemia). Affected individuals experience extreme tiredness (fatigue) due to low numbers of red blood cells (anemia), frequent infections due to low numbers of white blood cells (neutropenia), and clotting problems due to low numbers of platelets (thrombocytopenia). People with Fanconi anemia may also develop myelodysplastic syndrome, a condition in which immature blood cells fail to develop normally.

People with Fanconi anemia often have growth problems before or after birth that often result in short stature. Affected individuals can also have irregular skin coloring such as unusually light-colored skin (hypopigmentation) or café-au-lait spots, which are flat patches on the skin that are darker than the surrounding area. People with Fanconi anemia can have skeletal problems that often include malformed thumbs or forearms or an unusually small head size (microcephaly).

Problems in hormone-producing (endocrine) tissues are common in people with Fanconi anemia, including abnormally low levels of thyroid hormones (hypothyroidism), and high blood glucose levels (hyperglycemia). Individuals with Fanconi anemia can also have eye abnormalities such as small or abnormally shaped eyes or malformed or absent kidneys and other defects of the urinary tract.  Less frequent problems include gastrointestinal abnormalities, heart defects, brain abnormalities, and hearing loss. People with Fanconi anemia may have abnormal genitalia or malformations of the reproductive system, which can result in difficulty having biological children (infertility).

Individuals with Fanconi anemia have an increased risk of developing a cancer of blood-forming cells called acute myeloid leukemia (AML). They are also at risk of developing tumors of the liver, gastrointestinal system, genital tract, or head and neck (known as head and neck squamous cell carcinoma). The likelihood of a person with Fanconi anemia developing one of these cancers is between 10 and 30 percent.