Hb Strasbourg alpha2beta2 20 (B2) Val leads to Asp: a variant at the same locus as Hb Olympia beta 20 Val leads to Met

Hb Luxembourg [alpha 24(B5) Tyr----His]: a new unstable variant

Hb Luxembourg [alpha 24(B5)Tyr----His] was found in association with mild hemolytic anemia and increased indirect bilirubinemia in a family originating from the Netherlands. The slight instability of this variant may be the consequence of an indirect effect of the substitution on the alpha 1 beta 1 contact since position alpha 24 (B5) is internal and in contact with several residues involved in this interface.

Hemoglobin Miyashiro (beta 23[B5] val substituting for gly) an electrophoretically silent variant discovered by the isopropanol test

A new unstable hemoglobin was discovered in a Japanese boy without any signs of hemolytic disease during screening of patients by the isopropanol test. The abnormal hemoglobin was found in three generations. This slightly unstable hemoglobin could not be separated from Hb A by electrophoresis. All carriers showed an increased whole blood oxygen affinity. Structural studies demonstrated a previously unreported amino acid substitution, beta 23[B5] valine substituting for glycine. This new unstable variant has been named Hb Miyashiro.

The restriction of codon ambiguity on the basis of known variants

The genetic code may be used to formulate the nucleotide sequence of a messenger RNA from the known amino acid sequence of a protein. Unfortunately, the degeneracy of the code means that there will be ambiguity in the nucleotide assignments in a third or more of the positions. A simple procedure is given that utilizes the information of known genetic variants to reduce that ambiguity. Problems associated with silent polymorphism are treated. The human alpha and beta hemoglobins are used to exemplify the technique. A total of 68 nucleotides in the two sequences are thereby made less ambiguous. One reduction leads to a nucleotide inconsistent with the result of the recently published beta hemoglobin sequence.