Hb Barika [alpha42(C7)Tyr-->His (alpha2)] leads to an alpha+ -Thalassemia-like syndrome.
In human deoxyhemoglobin (deoxyHb), the hydrogen bond between Aspbeta99(G1) and Tyralpha42(C7), located in the alpha1beta2 interface, is crucial for the stability of the T structure. All the variants that could arise from a single point mutation affecting codon beta99 have already been observed, leading always to erythrocytosis. Conversely, up to now, Hb Barika is the only example found in a patient in whom the alpha42 is mutated. From a biochemical point of view, for theoretical reasons, this substitution has already been extensively studied on recombinant hemoglobin (rHb). In the patient, Hb Barika is expressed at a level lower than expected for an alpha2 gene variant and leads to an alpha+-thalassemic-like syndrome.
Préhu
Claude
C
INSERM U654 and Service de Biochimie, Hôpital Henri Mondor AP-HP, Créteil, France.
Riou
Jean
J
Wajcman
Henri
H
D000595:Amino Acid Sequence / Q000235:genetics; D000747:Anemia, Hypochromic / Q000235:genetics*; D001483:Base Sequence; D002675:Child, Preschool; D004252:DNA Mutational Analysis; D005914:Globins / Q000737:chemistry / Q000235:genetics; D006455:Hemoglobins, Abnormal / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D010375:Pedigree; D013329:Structure-Activity Relationship; D017085:alpha-Thalassemia / Q000175:diagnosis / Q000235:genetics*
D006455:Hemoglobins, Abnormal; C519336:hemoglobin Barika; D005914:Globins