Frequencies and phenotypic consequences of association of α- and ß-thalassemia alleles with sickle-cell disease in Bahrain.

INTRODUCTION: Bahrain has high prevalence rates of sickle cell and thalassemia in the population. This study reports the frequencies and phenotypic characteristics of α- and/or ß-thalassemia associated with sickle-cell disease (SCD) in a tertiary care hospital. METHODS: Adult SCD patients (n = 200) were screened for the common α- and ß-thalassemia alleles prevalent in the region using molecular techniques. Results of CBC, hemoglobin analysis, and average annual frequencies of severe pain episodes and numbers of transfused red cell units were documented. RESULTS: Patients were grouped on the basis of molecular studies as sickle-cell anemia (SS, n = 131), SS/α-thalassemia with three normal genes (n = 27), SS/α-thalassemia with two normal genes (n = 11), sickle-ß-thalassemia (Sß, n = 23), and Sß with co-inherited α-thalassemia (n = 8). Identified α-thalassemia determinants were -α3.7 (n = 52), -α4.2 (n = 4), αT-Saudi α (n = 1), and αHph α (n = 1). All ß-thalassemia alleles were ß0 defects. Sickle-thalassemia association resulted in higher hemoglobin, hematocrit, and erythrocyte counts with reduced MCV and reticulocytes. Significant clinical associations were as follows: increased severe pain frequency with α-thalassemia (three-gene group); red cell transfusion with ß-thalassemia alleles and female gender. CONCLUSION: One-third of patients with SCD co-inherited α- and/or ß-thalassemia alleles and these associations explained some of the observed phenotypic variability. A low prevalence of nondeletion α-thalassemia alleles was observed in these patients. The most significant disease amelioration occurred in SCD associated with two α-thalassemia alleles.

Hemoglobinopathies and glucose-6-phosphate dehydrogenase deficiency in hospital births in Bahrain.

In view of the high prevalence of clinical cases of sickle cell anemia, hemoglobin-H-disease and glucose-6-phosphate dehydrogenase deficiency in the archipelago of the State of Bahrain, a cord blood screening study was undertaken over a 15 month period (October 1984 to December 1985) to determine the gene frequency of these diseases. All the state hospitals participated in this study and a total of 10,327 cord blood samples obtained from babies born to Bahraini parents were analyzed. These presented over 80% of all neonates born in the country during the study period. The phenotypes detected included: AF, AF-Barts, SFA and SFA-Barts. Homozygous sickle cell disease was detected in 2.1%, and in 11.2%, the sickle cell trait was present. The incidence of alpha-thalassemia gene based on elevated Bart's hemoglobin was 24.3% in these neonates. The incidence of G6PD-deficiency was as high as 20.9%. Availability of these statistics has enabled the authorities in the Ministry of Health in collaboration with the National Hereditary Anemia Society to plan a comprehensive health care program for patients with hereditary diseases and their families.

Hereditary high-adenosine triphosphate syndrome: study of a new variant.

A new variant of hereditary hemolytic anemia in a family due to high adenosine triphosphate (ATP) is reported. The increase in ATP levels varied from 83 to 105% in the family members. Low 2,3-diphosphoglycerate levels and low 2,3-diphosphoglyceromutase activity were observed in three family members, with normal glucose-6-phosphate dehydrogenase and pyruvate kinase activity.

Associated red cell enzyme deficiencies and their significance in a case of congenital enzymopenic methemoglobinemia.

Examination of the red cell enzyme profile in a case of congenital methemoglobinemia has shown associated deficiencies of glutathione reductase (GR) and glutathione peroxidase (GSHPx) in addition to NADH-methemoglobin reductase deficiency. Contrary to expectations, GR and GSHPx deficiencies do not seem to have contributed to the methemoglobinemia in this case. The lack of symptoms in spite of a high methemoglobin (Hi) level (35%) appears to be due to the restriction of Hi to a small percentage of red cells.

Distribution of subtypes of hepatitis B surface antigen in Western India.

HBsAg subtype distribution of 105 positive samples showed 91.4% as ay type. The ay was predominant in different disease conditions, healthy carriers and posttransfusion hepatitis. The prevalence of ay in the Bombay sample is in contrast to the predominance of ad reported from North India. These findings may suggest multifocal infection in different regions of India.

Genetic studies among the endogamous groups of Lohanas of North and West India.

Four groups of Lohanas, belonging to the Gujarati, Sindhi and Punjabi were studied for various genetic markers. Lohanas have higher B than A and low Rh(D) negative (1.65-4.64%). The Hp1 gene ranges from 0.1557 to 0.2639; Gm1 is lower (0.34-0.55) than in other populations in Southern India. G-6-PD deficiency was prevalent in 3-8%. All the four groups have a high incidence of the thalassaemia trait and possess Hb-D. Hb, J, and L were also observed in two groups. Data was analysed for intergroup differences.

New laboratory method to detect hepatitis-B (Australia) antigen based on 'anomalous' lactate dehydrogenase isoenzyme.

A laboratory method for the indirect detection of hepatitis-B antigen (HB8Ag) based on the presence of 'anomalous' LDH isoenzyme by disc electrophoresis has been developed. The method is specific and highly sensitive when compared with existing methods.