More recently it has become clear that the severity of the condition is highly variable, and there is much genetic variability amongst those affected. See also
AMMECR1
List of hematologic conditions

References
External links

Hereditary Elliptocytosis Image of hereditary elliptocytosis
MedlinePlus Entry
Contraindications
Fluorouracil is contraindicated in patients who are severely debilitated and in patients with bone marrow suppression due to either radiotherapy or chemotherapy. It is likewise contraindicated in pregnant or breastfeeding women. It should also be avoided in patients who do not have malignant illnesses. Adverse effects
Adverse effects by frequency include:

During systemic use
Common (> 1% frequency):
Uncommon (0.1–1% frequency):

Rare (< 0.1% frequency):

Anaphylaxis
Allergic reactions
Fever without signs of infectionDiarrhea is severe and may be dose-limiting and is exacerbated by co-treatment with calcium folinate. Neutropenia tends to peak about 9–14 days after beginning treatment. Thrombocytopenia tends to peak about 7–17 days after the beginning of treatment and tends to recover about 10 days after its peak. Cardiotoxicity is a fairly common side effect, usually manifesting as angina or symptoms associated with coronary artery spasm, but about 0.55% of those receiving the drug will develop life-threatening cardiotoxicity. Life-threatening cardiotoxicity includes: arrhythmias, ventricular tachycardia and cardiac arrest, secondary to transmural ischaemia. During topical use
Common (> 1% frequency):

Uncommon (0.1–1% frequency):

hyper- or hypopigmentation
Scarring

Neurological damage
The United States package insert warns that acute cerebellar syndrome has been observed following injection of fluorouracil and may persist after cessation of treatment. Symptoms include ataxia, nystagmus, and dysmetria. Potential overdose
There is very little difference between the minimum effective dose and maximum tolerated dose of 5-FU, and the drug exhibits marked individual pharmacokinetic variability. Therefore, an identical dose of 5-FU may result in a therapeutic response with acceptable toxicity in some patients and unacceptable and possibly life-threatening toxicity in others.