What are the other Names for this Condition? (Also known as/Synonyms)

• Hb-Zurich

What is Hemoglobin Zurich? (Definition/Background Information)

• Hemoglobin (Hb) Zurich is an inherited blood disorder. People with Hb Zurich have an abnormal form of Hb, a red blood cell (RBC) protein that binds to oxygen in the lungs. This abnormal Hb more readily binds to carbon monoxide (producing carboxyhemoglobin or COHb)
• Normally, the level of COHb is less than 1-2% in adults. People with Hb Zurich tend to have COHb levels above 3%
• The health effects of Hb Zurich tend to be mild compared to other inherited blood cell disorders
• Symptoms usually develop only when the body is stressed due to an infection or fever or when exposed to certain drugs. Symptoms develop as a result of the premature breakdown of RBC (hemolytic anemia)

(Source: Hemoglobin Zurich; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

Who gets Hemoglobin Zurich? (Age and Sex Distribution)

• Hemoglobin Zurich is a rare congenital disorder. The presentation of symptoms may occur at any age, when an individual has an infection or fever
• Both males and females may be affected
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Hemoglobin Zurich? (Predisposing Factors)

The risk factors for Hemoglobin Zurich may include:

• A positive family history 
• Stress to the body due to infection or fever
• Exposure to certain chemicals/drugs, such as antimalarial drugs, aspirin and sulfonamide, among others

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Hemoglobin Zurich? (Etiology)

• Hemoglobin Zurich is caused by an abnormal form of hemoglobin, that binds readily to carbon monoxide, forming carboxyhemoglobin
• Carboxyhemoglobin is a stable form of carbon monoxide in hemoglobin. The presence of this compound does not allow blood to transport oxygen

(Source: Hemoglobin Zurich; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

What are the Signs and Symptoms of Hemoglobin Zurich?

The signs and symptoms of Hemoglobin Zurich may develop under stressful conditions for the body, including infection, exposure to certain chemicals and fever. The signs and symptoms of Hemoglobin Zurich may include:

Hemolytic anemia, which can lead to the following:

• Muscle pain
• Nausea and vomiting
• Shortness of breath
• Rapid breathing

How is Hemoglobin Zurich Diagnosed?

Hemoglobin Zurich is diagnosed on the basis of the following information:

• Complete physical examination
• Thorough medical history evaluation
• Assessment of signs and symptoms
• Laboratory tests, including checking for elevated levels of carboxyhemoglobin in blood (which is less than 1-2% in normal adults)
• Imaging studies
• Biopsy studies, if necessary

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Hemoglobin Zurich?

The complications of Hemoglobin Zurich may include:

• Excessive fatigue that may interfere with daily activities
• Enlarged heart
• Heart failure

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Hemoglobin Zurich Treated?

Individuals with mild hemolytic anemia generally do not require treatment. The treatment for severe cases of hemolytic anemia due to Hemoglobin Zurich may include:

• Blood transfusions
• Medicines
• Plasmapheresis 

In addition, affected individuals may be advised to understand triggers for hemolytic anemia and avoid them.

(Source: Hemoglobin Zurich; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

How can Hemoglobin Zurich be Prevented?

Currently, Hemoglobin Zurich may not be preventable.

• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Understanding the triggers for hemolytic anemia and avoiding them is one method of management of the condition for the prevention of severe hemolytic anemia
• Active research is currently being performed to explore the possibilities for treatment and prevention of such disorders

Regular medical screening at periodic intervals with tests and physical examinations are recommended.

What is the Prognosis of Hemoglobin Zurich? (Outcomes/Resolutions)

• The prognosis of Hemoglobin Zurich is dependent upon the severity of the signs and symptoms and associated complications, if any
• Individuals with mild conditions have better prognosis than those with severe symptoms and complications
• Typically, the prognosis may be assessed on a case-by-case basis

Additional and Relevant Useful Information for Hemoglobin Zurich:

• People with Hemoglobin Zurich should avoid sulfanilamide. Some cases of Hb Zurich behave similarly to glucose-6-phosphate dehydrogenase (G6PD) - in that they are especially sensitive to the oxidation of red blood cells
• These individuals may benefit from avoiding or limiting exposure to G6PD triggers, such as antimalarial drugs, aspirin, nitrofurantoin, nonsteroidal anti-inflammatory drugs (NSAIDs), quinidine, quinine, sulfonamide, fava beans, and mothballs

The following DoveMed website link is a useful resource for additional information:

http://www.dovemed.com/diseases-conditions/rare-disorders/