A second allele of spectrin alpha-gene associated with the alpha... phenotype (allele alpha Ponte de Sor) [letter]
Transcription
A second allele of spectrin alpha-gene associated with the alpha... phenotype (allele alpha Ponte de Sor) [letter]
From www.bloodjournal.org by guest on November 19, 2014. For personal use only. 1994 84: 2056 A second allele of spectrin alpha-gene associated with the alpha I/65 phenotype (allele alpha Ponte de Sor) [letter] L Boulanger, D Dhermy, M Garbarz, C Silva, J Randon, R Wilmotte and J Delaunay Updated information and services can be found at: http://www.bloodjournal.org/content/84/6/2056.citation.full.html Articles on similar topics can be found in the following Blood collections Information about reproducing this article in parts or in its entirety may be found online at: http://www.bloodjournal.org/site/misc/rights.xhtml#repub_requests Information about ordering reprints may be found online at: http://www.bloodjournal.org/site/misc/rights.xhtml#reprints Information about subscriptions and ASH membership may be found online at: http://www.bloodjournal.org/site/subscriptions/index.xhtml Blood (print ISSN 0006-4971, online ISSN 1528-0020), is published weekly by the American Society of Hematology, 2021 L St, NW, Suite 900, Washington DC 20036. Copyright 2011 by The American Society of Hematology; all rights reserved. From www.bloodjournal.org by guest on November 19, 2014. For personal use only. CORRESPONDENCE 2056 Phenotype (Allele aPonle de 1 ASecondAllele of Spedrin a-Gene Associated With the Family SV To the Editor: Many mutations of spectrin a-gene result in hereditary elliptocytosis (HE) and are manifested by various peptide map abnormalities. A given alteration may derive from several mutations located abnormalclose to one another. Inan opposite way, the so-called ity has long been found to be associated only with the duplication of TTG codon 154 (Leu).'.' defining allele a""ply, as hereafter designated. This allele has a mild expression and appears in people from Black Africa. Northern Africa, and Southern Italy. We describe here two unrelated kindreds with a symptomless a"65change. Unexpectedly, the underlying mutation was a distinct and novel change: 151 GGT GAT:Gly Asp. The mutated allele was termed allele a ~ ~P ~mW ~ + Family RN _" It 1 l Fig 1. Partial pedigrees. ( / ) Probands; (M) allele urmnd. =; (0) allele uLELv. -+ Unrelated families SV and RN were Portuguese and French, respectively (Fig I ) . All members were symptomless and disclosed normal red bloodcell indices. Elliptocytosis was observed in individuals SV 11.1 (40%) and RN 1.2 (20%). The methods used in protein chemistry have been described or referred to before.'," Segments of genomic DNA encompassing exon 2, 3, and 4 were amplified by polymerase chain reaction andsequenced directly or after subcloning in plasmid vector PGEM3Z. In some experiments, amplified DNA was digested using BstEll or Fok I. The percentage of spectrin dimers in crude Sp extracts (4°C) was normal in three members of family SV (it was not investigated in family RN). In individuals SV 1.2 and SV 11.1. two-dimensional maps of spectrin disclosed the presence of a spot defining the a''" phenotype (data not shown). Partial amino acid sequencing showed that this fragment arose from an abnormal cleavage after Arg 137, as is observed in the presence ofthe aDup allele, and disclosed the 151 Glu Asp substitution. Nucleotide sequencing (individual SV 11.1 and RN 11.1) displayed the 151 GGT -+ GAT change and ruled out the duplication of TTG codon 154 (Fig 2). Whenever they were looked for, a RsrEll site was abolished and a Fok I site was created due IO the a151 mutation (data not shown). Nucleotide sequences of exons 2 and 3 (individual 11.1) did not show any additional alteration. Quantification of the a V 41-kD fragment" and assessment of exon 40 mutation' established heterozygosity for allele al.l;l.Y , a low expression allele, in four individuals (Fig l). Taken together, two unrelated kindreds displaying the pheno'sl mutation but bore a novel type failed to carry the common anuP mutation at position I5 1 . The latter created the same abnormal trypsin cleavage site after Arg 137. A limited elliptocytosis accompanied the al.lil.Y/aPa,ntC de SOr diplotype, but not the a""""dc '"/a diplotype. The modulation by allele assigned the primary alteration to spectrin a-gene. The normal sequence of exons 2 and 3 ruled out the possibility of any other mutation in the same conformational unit (helices 2 or 3) or in helix I of repeat a2.Finally, the resemblance of I" andthe fact that the picture yielded by alleles aP""" si,' and the latter is held responsible for elliptocytosis led us to consider that the former yields elliptocytosis in a like fashion. + ACKNOWLEDGMENT Supported in part by the "Association Franqaise contre les Myopathies." the "Conseil Scientifique de I'UFR Xavier-Bichat, UniversitC Paris VII," the "Centre National de la Recherche Scientifique," and the "lnstitut Pasteur de Lyon." We thank Dr L. Denoroy (CNRS URA 1195. Lyon, France and Service Central d'Analyse. CNRS, Vernaison, France) for having performed partial amino acid sequencing. Laurent Boulanger Didier Dhermy Michel Garbarz INSERM U409 Faculte X . Bichat Paris, France Candido Silva Lahorarorie de Hernarologia Hospital de Santa Cruz Camaxide, Portugal Jacques Randon Rick Wilmotte Jean Delaunay CNRS LIRA I171 Institut Pasteur de Lyon L.yon. France REFERENCES I . Roux AF, Mode L, Guetarni D, Colonna P, Sahr K, Forget BG, Delaunay J. Godet J: Molecular basis of Spa'"' hereditary elliptocytosis in North Africa: Insertion of a T G triplet between codon 147 and 149 in the a-spectrin gene from five unrelated families. Blood 73:2196.1989 2. Sahr KE. Garbarz M, Dhermy D, Lecomte MC, Boivin P. Agre P, Laughinghouse K, Scarpa A, Coetzer T, Palek J, Marchesi SL, Forget BC: Use of the polymerase chain reaction for the detection and characterization of mutations causing hereditary elliptocytosis, in Cohen CM, Palek J(eds): Cellular and Molecular Biologyof Normal and Abnormal Erythroid Membranes. New York, NY, Wiley-Liss. 1990, p 201 3. Lecomte MC, Gautero H, Garbarz M,BoivinP,Dhermy D: Abnormal tryptic peptide from the spectrin a-chain resulting from a-or P-chain mutations: Two genetically distinct forms of the Spa" variant. Br J Haematol 76:406. 1990 4. Baklouti F, Marechal J, Wilmotte R, Alloisio N. Morle L, Ducluzeau MT. Denoroy L, Mrad A, Ben Aribia MH, Kastally R, Delaunay J: Elliptocytogenic a'"' spectrin Sfax lacks 9 amino acids in helix 3 of repeat 4. Evidence for the activation of a cryptic S' splice site in exon 8 of spectrin a-gene. Blood 79:2464, 1992 5. Wilmotte R, Marechal J, Mode L, Baklouti F, Philippe N. Kastally R, Kotula L, Delaunay J, Alloisio N: Low expression allele al.El.Y of red cell spectrin is associated with mutations in exon 40 polymorphism) andintron 45 andwithpartial exon 46. J Clin Invest 91:2091, 1993 skipping of From www.bloodjournal.org by guest on November 19, 2014. For personal use only. 2057 CORRESPONDENCE 3' Leu Leu Y NORMAL MUTANT " 1 ASP Glu Fig 2. Nucleotidesequencing of part of exon 4 (individual SV 11.1). Leu Q c (3 r C Q T T A T Q C Gin 3' 7 Q G A C C Q A Q T Q 0 T A Q v C 5' Gln C C A Q T Leu ".. . .c - ,.,. .I I A C G T ACGT \ \a Q A LYS Giu ,C" L 5' Leu