Alloalbuminemia in Sweden: structural study and phenotypic distribution of nine albumin variants.
Plasma samples exhibiting alloalbuminemia on electrophoresis at pH 8.6 were requested from clinical laboratories throughout Sweden. Nine variants, each representing a different single point mutation, were found in 100 apparently unrelated Swedes. The overall prevalence of alloalbuminemia was estimated at 1:1700. Mutations were identified by protein-structural analysis followed by allele-specific DNA hybridization to verify the most common types. Slightly retarded (+1) mobility was seen in 80 cases. Of these, 71 had the Arg(-2)----Cys proalbumin variant previously called Malmö I proalbumin. Thirteen examples of the second most frequent type, the substitution Lys313----Asn and a mobility change of -1 charge unit, were found, as well as six cases of Glu570----Lys (albumin B) and a single case of Arg-1----Gln (proalbumin Christchurch). Five previously unreported types of alloalbuminemia were identified: four instances of Glu376----Gln, which is the second known mutation at this site; two examples of Asp550----Ala, the second mutation reported at this site; and one example each of Asp63----Asn, Gln268----Arg, and Asn318----Lys. Other mutations were identified among eight subjects of foreign descent. The high frequency and relatively uniform geographic distribution of the Arg-2----Cys mutation suggest that it may have occurred in a founder individual many generation ago in Sweden.
Carlson
J
J
Department of Clinical Chemistry, University of Lund, Malmö General Hospital, Sweden.
Sakamoto
Y
Y
Laurell
C B
CB
Madison
J
J
Watkins
S
S
Putnam
F W
FW
D000595:Amino Acid Sequence; D001483:Base Sequence; D004586:Electrophoresis; D005787:Gene Frequency; D006801:Humans; D008969:Molecular Sequence Data; D009532:Nickel / Q000378:metabolism; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D011498:Protein Precursors / Q000737:chemistry; D012709:Serum Albumin / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D013548:Sweden
D009838:Oligodeoxyribonucleotides; D011498:Protein Precursors; D012709:Serum Albumin; D009532:Nickel