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Hemoglobin Hammersmith, a rare, unstable hemoglobin variant, was diagnosed in a 9-year-old Japanese girl. She presented with the typical manifestations of this disorder, including neonatal hyperbilirubinemia, followed by progressive hepatosplenomegaly, jaundice, and bilirubinuria. Because of severe hemolytic anemia, she received transfusions of red blood cells every 3 to 4 weeks. However, she underwent splenectomy at the age of 4 years and has continued to be in partial remission without requiring further transfusions. DNA sequence analysis of the polymerase chain reaction-amplified beta-globin gene revealed a point mutation (T --> C) in the second nucleotide of the 42nd codon of the beta-globin chain (beta 42(CD1) Phe --> Ser)., ((c) 2005 Wiley-Liss, Inc.)

Based on studies on 610 cases of hereditary red cell membrane disorders, the characteristic features of the incidence of these disorders in the Japanese population are described. These patients were screened by a protocol on red cell morphology (scanning electron microscopy), on red cell membrane proteins (sodium dodecylsulfate polyacrylamide gel electrophoresis, and kinetics of membrane proteins), biophysical studies (ektacytometry, mechanical stability and fluorescence recovery after the photobleaching method), membrane transport (sodium influx and efflux, and anion transport), gene analysis (spectrins, band 4.2 and band 3), surface markers (blood type antigens and sialic acid content), and development and expression of membrane proteins (using a two-phase liquid culture system). Among the molecular abnormalities detected, alpha-spectrin mutation appeared rare (only one family with spectrin alpha I/74), as opposed to two beta-spectrin mutations in Japan out of seven worldwide cases. Two unrelated kindreds with a chromosomal abnormality; that is, del (8) (p11.2-p21.1), were found that involved the possible contribution of ankyrin to the pathogenesis of hereditary spherocytosis. Anomalies of a transmembrane domain of band 3 were detected in two independent kindreds with impaired anion transport. Among 16 HE patients, 13 cases were partially band 4.1 deficient. Complete band 4.2 deficiency of the Nippon type (GCT-->ACT at codon 142 in band 4.2 gene) was observed in 17 cases of 13 unrelated kindreds. Other forms of band 4.2 deficiency without the mutation were also detected in three kindreds. Band 7 deficiency was found in seven cases with hereditary stomatocytosis independent of the presence or absence of cation transport abnormalities. A relatively high incidence of hereditary high red cell membrane phosphatidylcholine hemolytic anemia was disclosed by the analysis of red cell membrane lipids.

We cloned and sequenced the cDNAs for R-type pyruvate kinase (R-PK) from three homozygous PK patients. A point mutation (1151ACG to ATG) identified in the R-PK cDNA of PK Nagasaki was identical with that previously identified in an unrelated family, PK Tokyo. The mutation has also been identified in the PK L gene of a Lebanese family, PK Beirut, by Neubauer et al (Blood 77:1871, 1991). These results suggest either that the point mutation is very old or that the same mutation occurs sporadically in the same hot spot in unrelated families. A point mutation, 1261CAG to AAG, was detected in both PK Fukushima and PK Maebashi; this mutation causes a single amino acid substitution, from Gln421 to Lys, in R-PK. Consequently, the hydrophobicity properties near the mutated site are drastically changed. A silent mutation (1705AGG to CGG) was also identified in those variants. The screening of these three point mutations showed only the silent mutation in a normal individual as well as in individuals with PK variants. These results indicate that the multiplicity of the mutant PK allele is smaller than expected, and that the silent mutation is a polymorphic change commonly distributed in the Japanese population.

A Japanese family of congenital high red cell membrane phosphatidylcholine hemolytic anemia (HPCHA) is reported. The propositus was a 48-year-old woman, who had been followed up as hemolytic anemia of unknown origin and undergone splenectomy. She showed no improvement after splenectomy. She also had primary biliary cirrhosis, of which a diagnosis was made based on laboratory data and liver biopsy. Red cell morphology demonstrated stomatocytosis with erythroid hyperplasia in the bone marrow. Abnormal hemoglobins and the red cell enzyme activities were not demonstrated. A marked abnormality was noted in red cell membrane lipids, specifically the elevation of phosphatidylcholine (PC) and free cholesterol (FC), despite of normal plasma lipids and lecithin cholesterol acyltransferase activity. Sodium transport, both influx and efflux, was increased. Therefore, the diagnosis of HPCHA was confirmed. The three additional cases were found in her pedigree. The data on the red cells of her mother and elder sister were similar to hers with respect to the red cell lipids and sodium transport. The propositus and her mother showed no improvement of anemia or icterus after splenectomy. There are only three reports of the family with HPCHA in the world.

This is the first case of two siblings with congenital dyserythrobpoietic anemia (CDA) type I to be reported from a Japanese family. Both of these cases showed characteristic morphological aberration of erythroid precursors, ineffective erythropoiesis, and negative acidified serum test. The ultrastructural study of erythroblasts also revealed characteristics quite compatible with CDA type I.

A 16-year-old Mexican male of Japanese ancestry was found to have a new glucose-6-phosphate dehydrogenase (G-6-PD) deficient variant, named Gd(-) Tepic after the birthplace of the maternal grandmother. A younger brother was also affected and the two sisters were heterozygous. The mother, an obligatory heterozygote, did not show the abnormal variant and the possible explanation of this phenomenon is discussed. From the clinical standpoint, the propositus has had three mild hemolytic episodes while his siblings are so far asymptomatic.