Hereditary spherocytosis is a hemolytic anemia caused by an inborn metabolic defect in the red blood cell membrane. It is one of several common congenital hemolytic anemias in children. Most of the disease is autosomal dominant and a few are autosomal recessive. Normal red blood cells have a biconcave disc shape, much like the shape of a large round pancake that we usually eat. However, when there are metabolic abnormalities in the red blood cell membrane, these cells become spherical and these spherical red blood cells are destroyed in the spleen and liver, with the spleen being the main site of destruction of spherical red blood cells. Clinical manifestations Children with this disease usually have three symptoms. Anemia These abnormal spherical red blood cells are destroyed in the spleen and other organs, and when the destroyed red blood cells cannot be replaced in time, anemia occurs, manifesting as pallor and weakness. Jaundice When bilirubin produced by destroyed red blood cells is not treated in a timely manner, jaundice may occur, manifesting as yellowing of the sclera of the eyes, yellowing of the skin tone, yellowing of the urine, etc. Splenomegaly The destruction of red blood cells in the spleen, and other factors, causes splenomegaly, which can be palpable under the left rib cage. Thus, the three symptoms of anemia, jaundice, and splenomegaly are called the triad of hereditary spherocytosis. Clinically, there are two types of children with this disease, depending on the severity of the anemia. Moderate to severe anemia This group of children, often 1 to 2 days after birth (early neonatal period), show severe destruction of red blood cells and varying degrees of anemia, sometimes so severe that blood transfusion is required. Because of the destruction of red blood cells, the bilirubin rises, and the early neonatal period itself is accompanied by jaundice, so these newborns, with severe jaundice, often require blue light, etc., for anti-yellowing treatment. These children often have moderate to severe anemia after the newborn period, and blood transfusions should be started in infancy to correct severe anemia at the right time. Mild to moderate anemia In this group of children, the anemia is mild in the neonatal period and no severe jaundice is present. Parents sometimes ignore it. Sometimes the disease is not detected until late infancy, early childhood, or preschool age. These children are often mildly to moderately anemic and usually do not require blood transfusions. These two groups of children generally grow up with mild to severe jaundice, and children with less severe anemia may have intermittent jaundice. They have progressive enlargement of the spleen with age. However, in newborns that present with more severe anemia and high jaundice, the usual anemia is also more severe and the jaundice is more pronounced, as is the splenomegaly. In addition, in these children, “hemolytic crisis” is sometimes triggered by infection, fatigue or emotional stress during the chronic course of the disease, when anemia and jaundice suddenly increase. In this case, not only the red blood cells and hemoglobin decrease significantly, but also the white blood cells and platelets decrease. Laboratory tests Routine blood tests may show a decrease in red blood cells and hemoglobin. Liver function tests may show an increase in indirect bilirubin. Urinalysis may show positive urinary bilirubin. Other abnormalities are also seen, such as increased reticulocytes, decreased binding bead protein, increased lactate dehydrogenase, and increased free hemoglobin. There are also 2 special tests for this disease, namely the erythrocyte permeability fragility test and microscopic observation of erythrocyte morphology. Most children with this disease have increased erythrocyte permeability fragility. Some spherical red blood cells are visible under the microscope. Diagnosis The current diagnosis of the disease is based on the microscopic observation of more than 10% spherical erythrocytes and the combination of the above clinical manifestations and some laboratory tests, such as the more specific increased erythrocyte permeability fragility. However, in a small number of children, the number of spherical red blood cells is less than 10%, or the morphology of spherical red blood cells is not obvious, which makes the diagnosis of the disease not clear. In clinical practice, such children are sometimes encountered, especially in the infantile stage, with an inconspicuous spherical erythrocyte morphology. However, these children tend to show the spherical erythrocyte morphology gradually as they get older. Genetic testing This is a new test for the disease to find out if the causative gene for the disease is present in the child and to help in the diagnosis of the disease. If the presence of the disease gene is detected, the diagnosis of the disease can be further clarified by combining the clinical manifestations of the patient and laboratory tests that reveal spherical red blood cells >10%. It is also possible to assist in the diagnosis of children with clinical manifestations of the disease and positive laboratory tests, but with a spherical red blood cell count of less than 10%, through the discovery of the disease related causative gene. It is also important to identify whether the disease is common autosomal dominant or rare autosomal recessive when testing the child through genetic testing. In general, if the disease is autosomal dominant, the anemia is not severe and is mostly mild to moderate. In contrast, if the disease is autosomal recessive, the anemia is often severe. Genetic testing for this disease is technically complex and extremely high tech, and it takes about 2 months to produce a report, so testing is usually done at a professional genetic testing facility. Generally, when testing the causative gene of the child, it is recommended to test the related genes of the parents at the same time to clarify the relationship between the abnormal gene of the child and the abnormal gene of the parents. Treatment Once the disease is diagnosed, it is important to prevent and control infections, avoid fatigue, and avoid emotional stress. Take appropriate folic acid supplements. In case of severe anemia, transfusion of red blood cells is appropriate. Splenectomy treatment is effective in autosomal dominant cases. However, splenectomy should be performed after the age of 5 years, because premature splenectomy can reduce the immunity related to the spleen and may lead to serious infections in some infections. However, in cases of recurrent “aplastic crisis” or severe anemia resulting in growth retardation, the age of surgery may be earlier.