Stomatocytosis I (overhydrated hereditary stomatocytosis [OHSt]) is a rare condition that begins within the first year of life. OHSt causes red blood cells (RBCs) to become swollen with water. RBCs carry oxygen from the lungs to the rest of the body. Usually, RBCs have a balance of sodium and potassium. When the amount of sodium increases in the cell, potassium needs to leave the cell. In OHSt, too much sodium flows into the RBCs, causing an imbalance. This causes extra water to build up in the cells, and the cells break or become misshapen and unhealthy.
Unhealthy RBCs cannot deliver oxygen from the lungs to the body. This is known as hemolytic anemia. Hemolytic anemia can cause a person to feel grumpy, tired, dizzy, and weak. It can also cause headaches, trouble focusing, pale skin, dry nails, a sore tongue, and a blue color in the whites of the eyes.
OHSt causes iron overload, meaning you absorb too much iron from food. This can cause a person to feel tired and weak and can cause liver disease, darker skin, joint pain, diabetes, reproductive problems, heart disease, and thyroid disease.
People with OHSt may have a large spleen and/or liver. The spleen and liver are two organs in the body that break down old, unhealthy RBCs.
OHSt can be passed down from parent to child. It is inherited in an autosomal dominant pattern; only one mutation from one parent needs to be inherited by a child in order to cause symptoms. A child can also get OHSt randomly meaning the mutation is brand new in the child and not passed down from a parent.
OHSt is diagnosed with blood tests. The treatment for OHSt may include blood transfusions. A person with OHSt will be treated for hemolytic anemia and iron overload. If you or a family member has been diagnosed with OHSt, talk to your doctor about the most current treatment options. Support groups are also good sources of support and information.