Hereditary spherocytosis

Overall, individuals with hereditary spherocytosis (HS) who have had their spleen removed showed an improvement in quality of life.^[1].

Complete removal of the spleen (splenectomy) cures almost all patients with hereditary spherocytosis.^[2]  The spleen, however, is important in fighting infection.  Individuals, particularly children, who have had a splenectomy are more likely to contract a serious and possibly life-threatening infection (sepsis).  Most septic infections have been observed in children whose spleens were removed in the first years of life, although older children and adults also are susceptible.^[3]   Subtotal (partial) splenectomy is an effective alternative to total splenectomy; decreasing (but not eliminating) hemolysis (breakdown of red blood cells) and reducing the need for blood transfusions, while maintaining spleen function. ^[2][1] Subtotal splenectomy, however, is not effective in preventing gallstone formation.^[1]
 
Gallbladder removal (cholecystectomy) is a procedure that has been shown to help prevent biliary tract disease and, in some patients with mild HS, helps avoid the need for splenectomy.  Removal of the gallbladder has not been known to cause any long-term adverse effects, aside from occasional diarrhea.^[4]

About 75% of cases of hereditary spherocytosis are inherited in an autosomal dominant manner.^[5] This means that having a change (mutation) in only one copy of the responsible gene in each cell is enough to cause features of the condition. In some cases, an affected person inherits the mutated gene from an affected parent. In other cases, the mutation occurs for the first time in a person with no family history of the condition. This is called a de novo mutation. When a person with a mutation that causes an autosomal dominant condition has children, each child has a 50% (1 in 2) chance to inherit that mutation.

Less commonly, hereditary spherocytosis is inherited in an autosomal recessive manner.^[5] This means that to be affected, a person must have a mutation in both copies of the responsible gene in each cell. Affected people inherit one mutated copy of the gene from each parent, who is referred to as a carrier. Carriers of an autosomal recessive condition typically do not have any signs or symptoms (they are unaffected). When 2 carriers of an autosomal recessive condition have children, each child has a:

• 25% (1 in 4) chance to be affected
• 50% (1 in 2) chance to be an unaffected carrier like each parent
• 25% chance to be unaffected and not be a carrier

In some of the cases that result from new mutations in people with no family history of the condition, the inheritance pattern may be unclear.^[5]