Hb Sun Prairie or alpha(2)130(H13)Ala----Pro beta 2, a new unstable variant occurring in low quantities.
A severe hemolytic anemia with microcytosis and hypochromia was present in a young adopted Indian patient. Reversed phase high performance liquid chromatographic methodology and heat stability tests detected an unstable alpha chain which was present in 3 to 5% of the total hemoglobin. A larger quantity of the alpha X chain was obtained by preparative reversed phase high performance liquid chromatography. Structural analyses identified an Ala----Pro replacement at position 130 of the alpha chain. The instability of the variant, named Hb Sun Prairie, is comparable to that of Hb Bibba [alpha 136 (H19)Leu----Pro]. Gene mapping failed to detect an alpha-thalassemia deletion (alpha alpha/alpha alpha), while dot-blot analysis of amplified DNA with synthetic probes localized a G----C mutation in codon 130 (resulting in the Ala----Pro mutation) of the alpha 2-globin genes of both chromosomes. These results suggest a homozygosity for the G----C mutation and the condition alpha 2(G----C)alpha 1/alpha 2(G----C)alpha 1 adequately explains the rather severe clinical status of this child, including the marked microcytosis and hypochromia. Unfortunately, family studies to exclude the presence of a large deletion involving all zeta- and alpha-globin genes were not possible.
Harkness
M
M
Department of Pediatrics, University of Wisconsin, Madison 53792.
Harkness
D R
DR
Kutlar
F
F
Kutlar
A
A
Wilson
J B
JB
Webber
B B
BB
Codrington
J F
JF
Huisman
T H
TH
D000595:Amino Acid Sequence; D000745:Anemia, Hemolytic, Congenital / Q000097:blood*; D001483:Base Sequence; D002675:Child, Preschool; D006455:Hemoglobins, Abnormal / Q000032:analysis / Q000737:chemistry* / Q000235:genetics; D006801:Humans; D007194:India; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D015183:Restriction Mapping
D006455:Hemoglobins, Abnormal; C067961:hemoglobin Sun Prairie