Fanconi Anemia (FA)
Fanconi anemia (FA) is a rare recessive genetic disorder that affects individuals of all ethnic and racial groups, although the disease is disproportionately more common among individuals of Jewish Ashkenazi (Eastern European) descent, with a carrier frequency of 1 in 90. Fanconi anemia was first described by Swiss pediatrician Guido Fanconi. FA should not be confused with Fanconi syndrome, a rare kidney disorder that causes the afflicted individual to lose nutrients through urination. Children whose parents are both carriers of FA have a 1 in 4 chance of developing the disease, which is generally diagnosed when the child is between 2 and 15 years of age.
There are 13 genetic mutations known to cause FA, specifically mutations on genes FANCA, FANCB, FANCC, FANCD1, FANCD2, FANCE, FANCF, FANCG, FANCI, FANCJ, FANCL, FANCM and FANCN. All are autosomal recessive with the exception of FANCB, which is found on the X chromosome.
The genetic mutations responsible for causing FA prevent cells from fixing damaged DNA or eliminating oxygen-free radicals that cause cellular damage. The result is blood count problems, such as low red blood counts, low white blood counts, and an insufficient number of platelets. The most common symptoms of FA include: irregular skin pigmentation; short stature; malformed kidneys; extra, missing, or misshaped thumbs and other upper limb problems; scoliosis and other bone abnormalities; malformed or unusually small genitals; and a malformed digestive tract. Symptoms of babies and children with FA include a failure to thrive, mental retardation, low birth weight, and learning disabilities.
The tests used to diagnose FA include: bone marrow biopsy; kidney ultrasound; chromosomal breakage analysis; HLA tissue typing; CAT scans and/or MRI; and hearing and other developmental tests. Pregnant women who wish to test their unborn child for FA can undergo amniocentesis or chronic villous sampling.
Treatment and Prognosis
FA can range from mild to severe. FA patients can undergo transfusions, hormone therapy (a short term treatment only), and bone marrow transplants to treat blood count problems, take antibiotics, and take growth factors such as erythropoietin, G-CSF, and GM-CSF to improve blood counts. While treatments for FA have improved considerably, afflicted individuals remain at high risk for several types of cancer, including myelodysplastic syndrome, acute myelogenous leukemia, and head and neck, esophageal, gastrointestinal, vulvar, anal, and liver cancer. A significant number of FA sufferers do not reach adulthood.
This post is part of the series: The Ashkenazi Jewish Genetics Panel
This series describes the diseases tested for in the Ashkenazi Jewish Genetics Panel (AJGP).