Molecular Genetics of Inherited Red Cell Membrane Disorders

Abstract

Inherited red cell membrane disorders constitute a diverse group of disorders which are characterized by wide clinical and molecular heterogeneity. They are nonimmune hereditary hemolytic anemia, and patients present with variable degrees of pallor, episodic jaundice, splenomegaly, and elevated lactate dehydrogenase (LDH) levels. The underlying cause is the defects either in the organization of membrane structure or membrane transport function arising because of mutations in genes encoding erythrocyte membrane proteins essential for stable structure and function. The commonest disorder is hereditary spherocytosis (HS) followed by relatively uncommon conditions such as hereditary elliptocytosis (HE) and hereditary pyropoikilocytosis (HPP). Disorders of alterations of hydration include hereditary stomatocytosis (HSt) where cation permeability in the red cell membrane is disturbed, leading to overhydrated HSt and hereditary xerocytosis with dehydrated HSt. Extensive biochemical, biophysical, and genetic studies of the red cell membrane in the decades have provided detailed molecular insights into the structural basis for normal red cell membrane function and for altered function in various inherited red cell membrane disorders.