Haemoglobin M Saskatoon and haemoglobin M Hyde Park in two Yugoslavian families

Cyanosis, hemolysis, decreased HbA1c and abnormal co-oximetry in a patient with hemoglobin M Saskatoon [HBB:c.190C > T p.His64Tyr]

We describe a first Dutch case of Hb M Saskatoon (HBB:c.190C > T p.His64Tyr) in a 47-year-old female Dutch patient who presented with cyanosis, hemolysis, and abnormal co-oximetry. A mean corpuscular volume (MCV) of 105 fL caused by reticulocytosis (160 × 10⁹/L) and low red blood cell count (3.6 × 10¹²/L) suggested an increased erythrocyte turnover. An HPLC glyco-globin analysis revealed a decreased HbA1c fraction of 12.3 mmol/mmol, HbA0 of 93.3% and an additional unidentified fraction at 1.2 min. DNA sequencing revealed a missense mutation in the HBB gene, (HBB:c.190C > T p.His64Tyr), known as Hb M Saskatoon, a variant which has been previously identified as an unstable hemoglobin variant leading to methemoglobinemia and anemia. In this report, we describe the clinical and remarkable laboratory aspects of our patient with Hb M Saskatoon, and the consequences for treatment and drug use.

DNA sequence analysis proves Hb M-Milwaukee-2 is due to beta-globin gene codon 92 (CAC-->TAC), the presumed mutation of Hb M-Hyde Park and Hb M-Akita

Among the causes of congenital methemoglobinemia, Hb M-Milwaukee-2 was one of the earliest described, in a patient who also had Hb E trait. The structure of Hb M-Milwaukee-2 has been elusive. DNA sequence analysis, as here reported, proves that this hemoglobin variant is due to the mutation CAC-->TAC at codon 92 of the beta-globin gene, corresponding to the substitution of tyrosine for histidine. This mutation is identical with that presumed to be the cause of Hb M-Hyde Park and Hb M-Akita. In addition, the DNA mutation of Hb E, GAG-->AAG at codon 26, was confirmed in this case.

Haemoglobin M-Hyde Park associated with polyagglutinable red blood cells in a South African family

Twelve of 35 members tested in a large ethnically-mixed South African family were found to have both haemoglobin M type Hyde Park and persistent polyagglutinable red blood cells. The characteristics of the polyagglutination have not been recorded previously. The cells of affected family members were not agglutinated by Arachis hypogea, Dolichos biflorus or Salvia sclarea, but were agglutinated weakly by Salvia horminum and BSII (GSII) and reacted strongly with Glycine soja and Sophora japonica lectins. BSI (GSI) lectin agglutinated the group A but not the group O cells. The N and MN cells were agglutinated more strongly than normal by Vicia graminea, other anti-N lectins and human anti-N but the M and MN cells reacted as expected with human anti-M. The name 'Hyde Park' is provisionally suggested for this type of polyagglutination, although it appears unlikely that the evidently complete association between the polyagglutination and the variant haemoglobin is the result of a single genetic mutation. More likely, the connection has a post-genetic origin, perhaps showing that bonds, possibly affected adversely by precocious senescence, normally occur between the haemoglobin and alpha-sialoglycoprotein molecules in red blood cells.