Hereditary spherocytosis is a condition that affects red blood cells. People with this condition typically experience a shortage of red blood cells (anemia), yellowing of the eyes and skin (jaundice), and an enlarged spleen (splenomegaly). Most newborns with hereditary spherocytosis have severe anemia, although it improves after the first year of life. Splenomegaly can occur anytime from early childhood to adulthood. About half of affected individuals develop hard deposits in the gallbladder called gallstones, which typically occur from late childhood to mid-adulthood.

Mutations in at least five genes cause hereditary spherocytosis. These genes provide instructions for producing proteins that are found on the membranes of red blood cells. These proteins transport molecules into and out of cells, attach to other proteins, and maintain cell structure. Some of these proteins allow for cell flexibility; red blood cells have to be flexible to travel from the large blood vessels (arteries) to the smaller blood vessels (capillaries). The proteins allow the cell to change shape without breaking when passing through narrow capillaries.

Hereditary spherocytosis occurs in 1 in 2,000 individuals of Northern European ancestry. This condition is the most common cause of inherited anemia in that population. The prevalence of hereditary spherocytosis in people of other ethnic backgrounds is unknown, but it is much less common.

In about 75 percent of cases, hereditary spherocytosis is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In some cases, an affected person inherits the mutation from one affected parent. Other cases result from new mutations in the gene and occur in people with no history of the disorder in their family.

Published Date: September 01, 2013
Published By: National Institutes of Health