Disease Description (Causes and Symptoms)
- Definition summary: Fanconi anemia is an inherited bone marrow failure syndrome caused by defects in cellular repair mechanisms for chromosomal damage. It is characterized by progressive pancytopenia, congenital abnormalities, and an increased risk of cancer, particularly hematologic malignancies and solid tumors.
- Causes and inheritance: It is associated with abnormalities in multiple genes involved in DNA damage repair (currently 13 or more, such as FANCA and FANCC) and is inherited mostly in an autosomal recessive manner (some genetic types are X-linked, etc.).
- Pathophysiology summary: Due to defective genes, repair of crosslinked DNA is insufficient, increasing chromosomal breaks and instability. The progressive loss of hematopoietic cells in the bone marrow leads to bone marrow failure, infections, bleeding, and anemia.
- Major clinical symptoms (summary, based on the provided data)
- Growth retardation, short stature, microcephaly (approximately 25–37%), and intellectual developmental delay in some cases (approximately 25%)
- External abnormalities such as skin hyperpigmentation and abnormal palms/fingers (including reduced creases, etc.)
- Ophthalmic abnormalities (ptosis, strabismus, nystagmus, etc.; approximately 41%)
- Skeletal abnormalities (rib, pelvic, spinal, and limb deformities, etc.), osteoporosis/osteomalacia, etc.
- Genitourinary and renal malformations/functional abnormalities (various genitourinary abnormalities reported in approximately 34% according to the data)
- Hematologic findings: progressive pancytopenia (anemia, neutropenia, thrombocytopenia), macrocytic anemia and reticulocytopenia, bone marrow failure, and progression in some cases to myelodysplastic syndrome and leukemia (such as acute myeloid leukemia)
- Other: Various congenital abnormalities, including cardiac, ear, and gastrointestinal malformations, as well as hearing loss, may occur concurrently.
- Cancer risk: Increased risk of hematologic malignancies (10–33% according to the data) and solid tumors (particularly head and neck squamous cell carcinoma, etc.; 28–29% according to the data)
Treatment Methods
- General principles: While controlling symptoms and complications, many patients undergo bone marrow transplantation as an attempt at definitive treatment over the long term. Each treatment is individualized based on the patient’s age, bone marrow function, complications, accompanying malformations, cancer risk, and other factors.
- Supportive care
- Transfusions (red blood cells and platelets) and management of anemia and bleeding
- Prompt use of antibiotics in cases of infection and management of neutropenia
- Specialist care as needed for growth and endocrine problems, nutritional management, osteoporosis treatment, etc. (endocrinology, orthopedics, etc.)
- Drug therapy
- Androgens (e.g., oxymetholone) may induce an increase in blood cell counts in some patients (temporary effect; side effects should be considered).
- Growth factors (e.g., G-CSF) may be used only for severe neutropenia, but the risk of malignant transformation of bone marrow cells should be assessed with long-term use.
- Definitive treatment
- Hematopoietic stem cell transplant (HSCT): A definitive treatment for correcting bone marrow failure. The timing and conditioning regimen (intensity of gamma radiation and chemotherapy) should be carefully determined according to the hematopoietic stem cell donor (sibling non-identical donor or alternative donor) and the patient’s condition. Because FA patients are sensitive to DNA damage, there is a tendency to use low-intensity conditioning regimens that take this sensitivity into account.
- Cancer surveillance and treatment
- FA patients have an increased risk of certain solid tumors (particularly head and neck cancer, skin cancer, etc.), so regular oral, skin, and otolaryngology examinations and early screening are recommended.
- If cancer develops, standard treatments (surgery, chemotherapy, and radiation) need to be adjusted because of DNA sensitivity (toxicity from radiation and some chemotherapeutic agents may be increased).
- Reproductive and genetic counseling and prevention
- Genetic testing of family members, carrier testing, and counseling about prenatal diagnosis and embryo testing are recommended.
- When preservation is possible (in adolescent and adult patients), counseling on fertility preservation (sperm and egg preservation) should be considered.
- Lifestyle management and precautions
- Prevention of infection and bleeding (hand hygiene; immediately visit a medical institution in the event of an acute infection)
- Smoking cessation, oral hygiene, skin protection, and regular checkups are recommended to manage cancer risk.
- Minimize radiation exposure (avoid unnecessary imaging tests).
- Counseling and vaccination related to vaccines (e.g., HPV) should be considered in consultation with the attending physician.
Checklist Before an Outpatient Visit (Items to Bring, Records, and Example Questions)
- Items to bring/records
- List of currently used medications and supplements (including dosage and frequency)
- Recent test results (copies of recent CBC, blood chemistry, urinalysis, and bone marrow examination results, if available)
- Records and dates of previous transfusions, infections, surgeries, and transplants
- Results of previous genetic tests and chromosome breakage tests (diepoxybutane/mitomycin C), if available
- Growth charts; for children, developmental assessment records and results of tests related to accompanying malformations (echocardiography, renal ultrasound, etc.)
- Family history records (similar symptoms, hematopoietic disorders, and cancer history)
- Key items the patient (or caregiver) may be asked about during the outpatient visit (it is helpful to organize these in advance)
- Recent frequency and severity of bruising, bleeding, gum bleeding, and nosebleeds
- Recent fever and infection episodes (including whether antibiotics were used)
- Changes in anemia-related symptoms such as fatigue, shortness of breath, and dizziness
- Whether transfusions are needed and the date of the last transfusion
- Changes in growth and development (for children)
- Reproductive plans (pregnancy, plans for pregnancy, or desire for fertility preservation)
Examples of General Questions to Ask the Doctor
- “What are the main side effects of this medication (or treatment), and how should they be managed if they occur?”
- “What is the expected prognosis for me (or the patient) given the current condition? How should long-term follow-up be conducted?”
- “Which lifestyle factors require particular attention, such as infection prevention and cancer prevention?”
- “Is there a genetic risk for family members? Should family testing be performed?”
Examples of Disease-Specific Questions
- “When is hematopoietic stem cell transplantation (HSCT) recommended in my situation, and what are the expected benefits and risks (particularly the risk of secondary cancer)?”
- “If the genetic (FA gene) test result is negative/positive, what testing or prenatal testing options are recommended for family members (siblings and children)?”