Ankyrin-linked hereditary spherocytosis in an African-American kindred

Am J Hematol. 2008 Oct;83(10):789-94. doi: 10.1002/ajh.21254.

Abstract

Mutations of ankyrin-1 are the most frequent cause of the inherited hemolytic anemia, hereditary spherocytosis (HS), in people of European ancestry. Ankyrin-1, which provides the primary linkage between the erythrocyte membrane skeleton and the plasma membrane, has numerous isoforms generated by alternative splicing, alternate polyadenylation, use of tissue-specific promoters, and alternate NH(2) or COOH-termini. Mutation detection in erythrocyte membrane protein genes, including ankyrin, has been a challenge, primarily due to the large size of these genes, and the apparent frequent occurrence of HS-associated null alleles. Using denaturing high-performance liquid chromatography (DHPLC), we screened the ankyrin gene of the proband of a large, three generation African-American kindred with ankyrin-deficient HS. DHPLC yielded an abnormal chromatogram for exon 1. Examination of the corresponding exon 1 sequence in genomic DNA from the proband revealed heterozygosity for a mutation of the initiator methionine (ATG to ATA Met 1 Ile). Coupled in vitrotranscription/translation studies with rabbit reticulocyte lysates demonstrated that the wild-type ankyrin erythroid cDNA initiates only from the known initiator methionine, indicating that the use of alternate initiator methionine is not a mechanism of isoform diversity in erythroid cells. The mutant ankyrin allele, unlike some initiator methionine mutations that utilize downstream codons for translation initiation, was associated with a null allele. This is the first report describing ankyrin-linked HS in an African-American kindred.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Alleles
  • Ankyrins / deficiency*
  • Ankyrins / genetics
  • Base Sequence
  • Black or African American / genetics*
  • Case-Control Studies
  • Chromatography, High Pressure Liquid
  • Codon
  • DNA Mutational Analysis
  • Exons
  • Family
  • Female
  • Gene Frequency
  • Genetic Testing
  • Heterozygote
  • Humans
  • Male
  • Molecular Sequence Data
  • Mutation
  • Pedigree
  • Siblings
  • Spherocytosis, Hereditary / genetics*

Substances

  • Ankyrins
  • Codon