The only way a person can be infected with hereditary methemoglobinemia is if both of their parents had it. That is why it is called hereditary methemoglobinemia. There are two types of it, type one and type two. Most hereditary cases are type two. (Type one is for cases that are caused my chemicals.)
The most noticeable symptom of hereditary methemoglobinemia is a bluish tint to the skin and mucous membranes. There are also other symptoms. Such as, but not limited to mental retardation, developmental delay, failure to thrive, seizures and other neurologic problems. The person may also have poor growth and weight gain. Many children who inherit this disease die during infancy. Symptoms can range from mild to life threatening. The severity increases as the metHB in the blood increases. If the number of metHB in the blood is less that ten percent, there are usually no symptoms what so ever. But if there is more that fifteen- percent lack of oxygen to the brain may occur. And worst case is if there is more that sixty- percent because then death can occur. The normal person has about two