Hereditary stomatocytosis (Hereditary stomatocytosis) - Gen SLC4A1.  

Stomatocytosis hereditary is a disorder characterized by the presence of erythrocytes abnormally resembling an oral cavity (stoma) and leading to hemolytic anemia. Affected individuals may have shortness of breath, chest pain and abdominal.

This process is due to mutations in the SLC4A1 gene, located on the long arm of chromosome 17 (17q21.31). This gene encodes a protein known as anion exchanger 1 (AE1). This protein carries anions across cell membranes. Specifically, AE1 chloride ion exchanged with bicarbonate ions. Based on this feature, known as an AE1 exchanger chloride / bicarbonate (HCO3- exchanger / Cl-). The main function of this exchanger is to maintain the correct pH levels in the body.

Two versions of the AE1 protein that differ in size. The shorter version is in the specialized kidney cells, called alpha-interleaved. Renal tubules reabsorb substances that are necessary and eliminate substances that are not necessary in the urine. In cells, the exchange of bicarbonate through the AE1 protein allows the acids to be released and excreted in urine. The longer version of AE1 is in the blood erythrocytes. Besides ions exchange, the AE1 protein binds to other proteins that comprise the cytoskeleton of erythrocytes, helping maintain its structure. In erythrocytes, the AE1 protein can interact with another protein called glycophorin A, which helps to ensure the transfer of AE1 to the correct location of the cell. Glycophorin A is not found in kidney cells.

Mutations in the SLC4A1 gene lead to abnormal protein AE1 allowing positively charged molecules with sodium ions (Na +) and potassium (K +) from leaking outside the cell. As a result, the erythrocytes are unstable and decompose faster than usual, leading to hemolytic anemia and related features.

This disease is inherited as an autosomal dominant, which means that a copy of the altered gene in each cell is sufficient for the disease to be expressed. In most cases, an affected person has a parent with the disease.

Tests in IVAMI: in IVAMI perform detection of mutations associated with hereditary stomatocytosis, by complete PCR amplification of exons SLC4A1 gene, and subsequent sequencing.

Samples recommended: EDTA blood collected for separation of blood leukocytes, or impregnated sample card with dried blood (IVAMI may mail the card to deposit the blood sample).