Haemoglobin G Norfolk: alpha 85 (F6) Asp leads to Asn.

The characterisation of haemoglobin G Norfolk (alpha2 85 Asp leads to Asn 2) is described. This variant has been identified in the heterozygous state in three apparently unrelated English families of which two are resident in England and the other in Canada.

Haemoglobin Titusville: alpha94 Asp replaced by Asn. A new haemoglobin with a lowered affinity for oxygen.

A new haemoglobin variant with a decreased oxygen affinity is described, in which the substitution, alpha 94 (G1) Asp replaced by Asn, affects the alpha1beta2 contact alpha1G1-beta2G4. The relevance of this variant to our understanding of the importance of the hydrogen bond between alpha1G1 and beta2G4 in Perutz's model of oxyhaemoglobin A is discussed.

Malignant hyperthermia in pigs: a search for abnormalities in Ca2+ binding proteins.

Malignant hyperthermia occurs in man and pigs as a hereditary disorder notably as a complication of halothane-induced anaesthesia. It involves an abnormality in the metabolism of Ca2+. A search was made for abnormalities of calcium-binding proteins. Troponin C from normal pig muscle was found to differ in 2 of 159 amino acids from rabbit Tn C and 3 from man. No differences between normal and abnormal pig muscle were found. Two-dimensional electrophoresis of red cell calmodulin from normal and abnormal pigs also failed to demonstrate a difference.

Investigation of malignant hyperthermia: analysis of skeletal muscle proteins from normal and halothane sensitive pigs by two dimensional gel electrophoresis.

Two dimensional gel analysis of skeletal muscles from normal pigs and from pigs which were homozygous for halothane sensitivity showed no obvious differences in the patterns of spots attributed to the major contractile proteins and glycolytic enzymes. In muscle from a sensitive pig which died of heat shock under anaesthesia there was a selective loss of glyceraldehyde-3-phosphate dehydrogenase and aldolase, presumably owing to proteolytic activity. The progressive loss of these enzymes under anaesthesia could contribute to the mechanism of heat production by diverting fructose 1,6 diphosphate into a futile cycle.

A drug-induced haemolytic anaemia due to Hb Torino (alpha43(CD1)Phe replaced by Val). second finding in an Italian family.

The unstable haemoglobin, Tb Torino (alpha43(CD1)Phe replaced by Val), has been found for the second time in a family from the Treviso region of Italy. The haemoglobin has a slightly lower oxygen affinity than normal. In both cases, the abnormal haemoglobin is associated with inclusion body anaemia but the course of the disorder in the present case is much less severe than that previously reported. The oxygen affinity of the haemolysate has been measured and been found lower than normal.

Erythraemia due to haemoglobin San Diego.

A 63-year-old man with erythraemia was found to have a high affinity haemoglobin which was subsequently identified as Hb San Diego beta 109 (G11) Val leads to Met, recently described in a Filipino family (Nute et al, 1974). The oxygen affinity of the haemolysates was increased approximately two-fold at pH values between 6.04 and 7.90. The n value was nearly normal (2.5-2.9) in the upper range of saturation (70-95% oxygenation) but was somewhat diminished (1.9-2.1) below this range. In vitro biosynthesis of globin by reticulocytes showed that there was balanced synthesis of alpha and beta chains (alpha:beta ratio = 1).

Futher investigations of the gamma-chaina in a ghanaian adult, homozygous for hereditary perisitence of fetal haemoglobin. Isolation of gamma CB-3 peptides and Ggamma:Agamma ratio determination in human Hb E.

The gamma-chain in a Ghanain homozygous for hereditary persistence of fetal haemoglobin was considered to be of the Ggamma type on the basis of the amino acid analysis of gammaTp XIV (gamma133-144) of the Hb F of this subject [1]. Recently, the sequence of residues gamma134-137 of the gamma-chain of this subject was determined and found to contain some alanine at position gamma136. It is therefore of the Ggamma + Agamma type. A rapid technique for the isolation of gammaCB-3 (gamma134-146) peptides in human fetal haemoglobin for Ggamma:Agamma ratio determination is described.

Haemoglobin Belfast 15 (A12) tryptophan leading to arginine: a new unstable haemoglobin variant.

A new unstable haemoglobin, alpha(2)beta(2)15 Trp--> Arg (Hb Belfast), with increased oxygen affinity has been found during the routine investigation of a long-stay psychiatric patient. It seemed to cause little haematological disorder. The reticulocytes synthesized normal and abnormal beta-chains at the same rate but in the circulating blood Hb Belfast amounted to only 27.5% of the total haemoglobin.

Familial polycythaemia caused by a new haemoglobin variant: Hb Heathrow, beta 103 (G5) phenylalanine leads to leucine.

A new variant of haemoglobin A (Hb A) with a high affinity for oxygen has been found in an English family. Five members are affected and all are polycythaemic. This variant (Hb Heathrow) is the first of this class to be found in this country and has the same electrophoretic mobility as Hb A. It was discovered only by measuring the oxygen affinity of the patients' red cells. This emphasizes the need for measuring the oxygen affinity of haemoglobin in patients with polycythaemia if other clinical and haematological features associated with polycythaemia rubra vera are absent.

Haemoglobin G-Szuhu, beta80 Asn-Lys, in the homozygous state in a patient with abetalipoproteinaemia.

An 11-year-old Jewish girl of Turkish extraction with abetalipoproteinaemia was found to be homozygous for haemoglobin Szuhu (beta80 Asn leads to Lys). Except for the abnormal haemoglobin, no other haematological or biochemical abnormalities were found in her consanguineous parents and one sister. In the propositus, erythrocyte morphology showed the acanthocytosis known to be in association with abetalipoproteinaemia. Increased autohaemolysis was also found, which reverted to normal after treatment with vitamin E. This case represents the first reported association of abetalipoproteinaemia with an abnormal haemoglobin, and the first homozygous Hb G-Szuhu.

Haemoglobin Rahere (beta Lys-Thr): A new high affinity haemoglobin associated with decreased 2, 3-diphosphoglycerate binding and relative polycythaemia.

A new haemoglobin with increased oxygen affinity, beta82 (EF6) lysine leads to threonine (Hb Rahere), was found during the investigation of a patient who was found to have a raised haemoglobin concentration after a routine blood count. The substitution affects one of the 2, 3-diphosphoglycerate binding sites, resulting in an increased affinity for oxygen, but both the haem-haem interaction and the alkaline Bohr effect are normal in the haemolysate. This variant had the same mobility as haemoglobin A on electrophoresis at alkaline pH but was detected by measuring the whole blood oxygen affinity; it could be separated from haemoglobin A, however, by electrophoresis in agar at acid pH. The raised haemoglobin concentration was mainly due to a reduction in plasma volume (a relative polycythaemia) and was associated with a persistently raised white blood count. This case emphasises the need to measure the oxygen affinity of haemoglobin in all patients with absolute or relative polycythaemia when some obvious cause is not evident.