Fanconi Anemia (FA)

FA patients have relatively specific physical findings in ~75% of affected persons. Laboratory findings include aplastic anemia, increased chromosome breakage in cells grown in the presence of a chemical which damages DNA, mutation in one of the 13 separate genes which have been identified ("cloned"), or assignment to one of the sub-categories into which patients with FA can be classified (known as "complementation groups"). Bone marrow failure is NOT required for the diagnosis, and ~25% of all persons eventually diagnosed as being affected by FA do not have the typical FA findings on physical examination. FA has been diagnosed at ages ranging from birth to >50 years of age. Males and females are affected equally.

1. What are the major findings on physical examination?
1. Cafe au lait spots (brown birth marks)
2. Short stature
3. Abnormal thumbs, often including abnormal radii (these are the bones in the lower arm, between the elbow and the wrist)
4. Abnormal male development, infertility
5. Small head
6. Small eyes
7. Abnormal kidneys
2. What is the age at diagnosis?
1. Anytime from birth to 50 years of age
2. Usually by age 10 to 15 years
3. What is the pattern of bone marrow failure?
1. Often called aplastic anemia, which is diagnosed when all 3 types of cells (red cells, white cells and platelets) are abnormally low because the bone marrow is not producing them.
2. Low red cell count ("anemia", often with large red cells)
3. Low platelet count (platelets are the cells in the blood which help the blood to clot)
4. Low white cell count (white cells help the body fight off infection)
4. What specific kinds of cancer develop?
1. Leukemia (cancer of the blood and bone marrow)
2. Liver tumors
3. Solid organ cancer
1. Cancers of the mouth, tongue and throat ("head and neck")
2. Cancers of the female genitals, particularly labial and cervical cancer ("gynecologic")
3. Cancer of the esophagus ("gastrointestinal")
4. Brain tumors
5. Possibly others
5. How is FA specifically diagnosed?
1. The chromosome breakage test
1. The patient’s blood cells are treated in the laboratory with a chemical which damages (breaks) DNA (the basic chemical for all genes).
2. The breaks are large enough to be seen under a microscope, and are counted.
2. Mutation analysis (genetic testing)
1. Laboratories can now identify the specific genetic "error" (or mutation) in some patients, in genes called FANCX, where X stands for the FA complementation group A through N.
2. There are at least 13 different gene pairs (complementation groups) responsible for FA: FANCA, FANCB, FANCC, FANCD1 (BRCA2), FANCD2, FANCE, FANCF, FANCG, FANCI, FANCJ, FANCL, FANCM, FANCN.
3. The disease is primarily inherited in an autosomal recessive manner (FANCB is X-linked, requiring inheritance of a mutant gene from the mother only). This means that illness occurs only if a person has two abnormal (mutant) genes from the same complementation group. One abnormal gene is inherited from each parent. Persons like the parents, who have only one copy of the abnormal gene, are called "gene carriers."