Fanconi anemia

Background

  • Fanconi anemia (FA) is the most common inherited bone marrow failure syndrome, characterized by progressive pancytopenia, congenital anomalies, and markedly increased cancer susceptibility.
  • Emergency physicians encounter FA patients presenting with hemorrhagic emergencies, febrile neutropenia, severe anemia, and malignancy complications.
  • Critically, FA patients have extreme sensitivity to DNA-damaging agents — standard-dose chemotherapy and radiation can cause fatal toxicity if FA is undiagnosed.[1] Not the same as Fanconi syndrome (a renal tubular disorder).
  • Autosomal recessive (most common) or X-linked recessive genetic disorder affecting DNA interstrand crosslink (ICL) repair[1]
  • Mutations in at least 22 FA genes (FANCA most common, ~65% of cases)
  • Prevalence approximately 1:350,000 births; carrier frequency ~1:300 in European/US populations[2]
  • Higher carrier frequency in Ashkenazi Jewish, Afrikaner, and Spanish Romani populations
  • Median age of diagnosis: 6-8 years; ~25% of patients have NO congenital anomalies and may not be diagnosed until adulthood[3]
  • 90% develop bone marrow failure by age 40[2]
  • Median mortality age ~20 years (improving with modern transplant techniques)
  • Leading causes of death: bone marrow failure > malignancy (AML/MDS, head/neck squamous cell carcinoma) > complications of transplant

Clinical features

What the EM physician will see

  • FA patients most commonly present to the ED with complications of pancytopenia:

Hemorrhagic emergencies

  • Epistaxis (often recurrent and severe)
  • Mucocutaneous bleeding, petechiae, purpura, ecchymoses
  • GI hemorrhage
  • Intracranial hemorrhage (particularly dangerous; high-impact activities should be avoided in thrombocytopenic patients)[4]
  • Menorrhagia in adolescent/adult females
  • Prolonged bleeding from wounds, dental procedures, or minor trauma

Infectious emergencies

  • Febrile neutropenia — the most dangerous acute presentation; treat as per standard febrile neutropenia protocols
  • Recurrent bacterial infections (pneumonia, skin infections, sinusitis, UTIs)
  • Oral candidiasis, fungal infections (in severe neutropenia)
  • Sepsis

Anemia-related symptoms

  • Fatigue, weakness, dyspnea on exertion
  • Dizziness, syncope, tachycardia
  • Pallor
  • High-output cardiac failure (rare, with very severe chronic anemia)

Congenital anomalies (present in ~75%)

  • Useful for recognizing the undiagnosed FA patient presenting to the ED:
  • Skeletal: absent or hypoplastic thumbs, absent/hypoplastic radii (always with thumb abnormalities), short stature, vertebral anomalies
  • Skin: café au lait spots (>50%), diffuse hyperpigmentation, hypopigmented patches
  • Head: microcephaly (25%)
  • Eyes: microphthalmia, strabismus, epicanthal folds
  • Ears: hearing loss (usually conductive), low-set or malformed ears
  • Renal: structural anomalies (horseshoe kidney, ectopic kidney, absent kidney) — 20%[2]
  • Cardiac: congenital heart defects — 5%
  • GI: tracheoesophageal fistula, esophageal/duodenal atresia, imperforate anus
  • Genitourinary: cryptorchidism, hypospadias, micropenis (males); structural uterine/vaginal anomalies (females)
  • VACTERL-H phenotype (vertebral, anal, cardiac, tracheoesophageal, renal, limb + hydrocephalus) found in ~12%[2]
  • 25% of FA patients have NO physical anomalies — suspect FA in any young patient with unexplained pancytopenia

Malignancy

  • AML/MDS: ~30% lifetime risk; may be the initial presentation of previously undiagnosed FA
  • Head and neck squamous cell carcinoma: greatly increased risk, particularly after stem cell transplant and in patients with graft-versus-host disease
  • Gynecologic malignancy: vulvar and cervical SCC
  • Liver tumors: hepatocellular carcinoma, hepatic adenomas (particularly in patients treated with androgens)
  • Critical EM pitfall: if an FA patient presents with leukemia or a solid tumor and is given standard-dose chemotherapy or radiation, extreme and potentially fatal myelosuppression will result due to impaired DNA repair[1]

Differential diagnosis

Other inherited bone marrow failure syndromes

  • Dyskeratosis congenita
  • Diamond-Blackfan anemia
  • Shwachman-Diamond syndrome
  • Thrombocytopenia-absent radius (TAR) syndrome

Other causes of pancytopenia

  • Aplastic anemia (acquired)
  • Myelodysplastic syndrome
  • Acute leukemia
  • Megaloblastic anemia (B12/folate deficiency)
  • HIV
  • Drug-induced myelosuppression
  • Systemic lupus erythematosus



Anemia

RBC Loss

RBC consumption (Destruction/hemolytic)


Impaired Production (Hypochromic/microcytic)

  • Iron deficiency
  • Anemia of chronic disease
  • Thalassemia
  • Sideroblastic anemia

Aplastic/myelodysplastic (normocytic)

  • Marrow failure
  • Chemicals (e.g. ETOH)
  • Radiation
  • Infection (HIV, parvo)


Megaloblastic (macrocytic)

Coagulopathy

Platelet Related

Factor Related

Evaluation

EM workup (acute presentations)

  • CBC with differential and peripheral smear:
    • Macrocytosis (elevated MCV — often the earliest hematologic abnormality; precedes cytopenias)[2]
    • Elevated fetal hemoglobin (HbF)
    • Thrombocytopenia (usually appears first)
    • Leukopenia/neutropenia
    • Anemia (develops later)
    • Smear: macrocytes, occasional target cells; blast cells if AML transformation
  • Reticulocyte count: low (hypoproliferative anemia)
  • Type and screen — anticipate transfusion needs
  • BMP: electrolytes, renal function (structural renal anomalies are common)
  • LFTs: hepatic adenomas and iron overload from chronic transfusion
  • Coagulation studies: if active bleeding
  • Blood cultures (at least 2 sets from separate sites) — before antibiotics if febrile neutropenia
  • Urinalysis, chest radiograph — as indicated by clinical presentation
  • Lactate, procalcitonin — if sepsis suspected
  • ECG — if congenital heart disease or cardiomyopathy suspected

When to suspect undiagnosed FA in the ED

  • Young patient with unexplained pancytopenia + macrocytosis ± congenital anomalies
  • Patient with unexpected severe toxicity from standard-dose chemotherapy or radiation
  • Early-onset malignancy (AML in a child/young adult; head/neck SCC in a young non-smoker)
  • Diagnosis is confirmed by chromosomal breakage (fragility) test using diepoxybutane (DEB) or mitomycin C — this is not an ED test but should be arranged via hematology consultation[1]

Management

Hemorrhagic emergencies

  • Platelet transfusion:
    • Use single-donor platelets (reduces alloimmunization risk)[3]
    • Leukodepleted (CMV risk reduction)
    • Irradiated (prevents transfusion-associated graft-versus-host disease)
    • Do NOT use blood products from family members — may sensitize the patient and compromise future stem cell transplantation[4]
    • Transfuse for active bleeding or platelets <10,000/μL (or <50,000/μL if surgery/invasive procedure planned)
  • Avoid:
    • NSAIDs and aspirin (impair platelet function)
    • IM injections (hematoma risk)
    • Rectal thermometers, suppositories, enemas (mucosal trauma)
  • Epistaxis: topical hemostatic agents, anterior packing; avoid posterior packing if possible due to mucosal fragility
  • Aminocaproic acid (Amicar) or tranexamic acid: may be used as adjunctive antifibrinolytic therapy for mucosal bleeding[4]

Febrile neutropenia

  • Manage per standard Febrile neutropenia protocols — this is a medical emergency
  • Fever (≥38.3°C single or ≥38.0°C sustained) + ANC <500/μL (or expected to fall below 500/μL)
  • Empiric broad-spectrum antibiotics within 1 hour of presentation (e.g., cefepime, piperacillin-tazobactam, or meropenem per institutional protocol)
  • Blood cultures before antibiotics (do not delay antibiotics for cultures if not immediately obtainable)
  • Low threshold for antifungal coverage if not responding to antibiotics within 48-72 hours
  • G-CSF (filgrastim) may be used for neutropenia-related infectious complications with ANC <500/μL[4]

Anemia

  • Packed RBC transfusion:
    • Leukodepleted, irradiated (same principles as platelets)[3]
    • Do NOT use family member donors
    • Transfusion threshold depends on clinical context; generally for hemoglobin <7 g/dL or symptomatic anemia
  • Monitor for transfusional iron overload in chronically transfused patients — serum ferritin, cardiac and hepatic MRI T2*

Airway considerations

  • Skeletal anomalies (vertebral, mandibular) may make intubation difficult[5]
  • Short stature may require smaller-than-expected equipment
  • Avoid nasal intubation if thrombocytopenic (nasal bleeding risk)
  • Avoid nitrous oxide (suppresses bone marrow via impaired methionine synthetase)[5]

Medication safety

  • Avoid NSAIDs and aspirin
  • Avoid IM injections
  • FA patients receiving androgens (oxymetholone, danazol) for bone marrow stimulation may have: hepatic dysfunction (peliosis hepatis, adenomas), virilization, lipid abnormalities — consider when interpreting labs
  • If cancer is diagnosed or suspected, do NOT initiate standard-dose chemotherapy or radiation in the ED — consult hematology/oncology experienced in FA management; profoundly reduced doses are required[1]

Disposition

  • Febrile neutropenia: admit; ICU if hemodynamically unstable or severely septic
  • Active hemorrhage with severe thrombocytopenia: admit to monitored setting; hematology consultation
  • Severe anemia (Hb <7 g/dL) or symptomatic: admit for transfusion and evaluation
  • New pancytopenia of unknown cause: admit or arrange urgent hematology follow-up; do not discharge without a plan for workup
  • Stable known FA patient with mild cytopenias: may discharge with close hematology follow-up and clear return precautions for fever, bleeding, syncope, or worsening weakness
  • All FA patients: ensure hematology is involved in care and aware of the ED visit
  • Educate patients/families:
    • Return immediately for any fever (even low-grade if neutropenic)
    • Avoid contact sports and high-impact activities (head trauma risk with thrombocytopenia)
    • Avoid NSAIDs
    • Wear medical identification

See Also

External Links

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 Fanconi Anemia. StatPearls. 2024. PMID: 32119428
  2. ↑ 2.0 2.1 2.2 2.3 2.4 Fanconi Anemia. GeneReviews. NCBI. 2026.
  3. ↑ 3.0 3.1 3.2 Fanconi Anemia. Medscape. 2024.
  4. ↑ 4.0 4.1 4.2 4.3 Fanconi Anemia: Guidelines for Diagnosis and Management. 4th ed. Fanconi Anemia Research Fund.
  5. ↑ 5.0 5.1 Anesthetic Management of a Patient With Fanconi Anemia. Anesth Prog. 2019;66(4):214-217. doi:10.2344/anpr-D-18-00057
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