Spectrin mutations in hereditary elliptocytosis and hereditary spherocytosis

Hereditary elliptocytosis (HE), its aggravated form hereditary pyropoikilocytosis (HPP), and hereditary spherocytosis (HS) designate a set of congenital hemolytic syndromes. The responsible mutations lie in several genes encoding proteins of the red cell membrane. In particular, they involve the SPTA1 and SPTB genes that encode erythroid spectrin α- and β-chains, respectively. In situ, spectrin is a α₂β₂ fibrillar tetramer resulting from the head-to-head self-association of two αβ dimers. In HE, the 24 known α-chain mutations lie in the self-association site or its vicinity, whereas the 17 β-chain mutations occur in the self-association site itself (record of November 30, 1995). Allele α^LELY (LELY: Low Expression LYon) is found in ethnic groups remote from one another with a uniform frequency (20–30% of all α-alleles). It allows an expanded expression of any HE α-allele located in trans and results in severe HE or in HPP. In HS, a number of spectrin mutations have been recorded recently. Allele α^LEPRA (LEPRA: Low Expression PRAgue) would occur in a recurrent fashion. © 1996 Wiley-Liss, Inc.