Clinical and hematological features of beta(+)-thalassemia (IVS-1 nt 5, G-C mutation) in Thai patients.

Seventy-eight patients with IVS-1 nt 5, G-C, which is the common mutation of beta+-thalassemia found in the southern part of Thailand, were studied to determine whether it is possible to predict phenotypic severity from genetic factors. The clinical phenotype of homozygotes for IVS-1 nt 5, G-C and compound heterozygotes for IVS-1 nt 5, G-C and beta(0) - or beta(+)-thalassemia were variable and could not be accurately predicted. The associations between concomittant alpha-thalassemia or Hb CS or the presence of XmnI-Ggamma polymorphism and a mild clinical phenotype are not apparent, indicating the involvement of other ameliorating determinants or genetic modifications.

Acquired platelet dysfunction with eosinophilia in children in the south of Thailand.

One hundred and sixty-eight children aged 13 months to 12.6 years with acquired platelet dysfunction with eosinophilia (APDE) were studied. The male to female ratio was 1.15:1. All of the children were in good health and no history of any drug ingestion was detected. All of the children had widespread spontaneous bruising on the extremities, body and face off and on. Severe bleeding symptoms were detected in 8% of these patients. The number of platelets in these children was within the normal range but the platelet morphology was abnormal in all of them. Eosinophilia was detected in 86% of these children. Prolonged bleeding time was detected in 53% of these patients. Abnormal platelet adhesiveness was found in 33% of cases. Abnormal platelet aggregation induced by collagen was the most sensitive test in these patients. Abnormal ADP release from the platelets was detected in these patients by the absence of a second wave of aggregation during stimulation of PRP by ADP or epinephrine. Abnormal or no ATP secretion from the platelets during stimulation by ADP, epinephrine or collagen was detected in these patients. Ristocetin-induced platelet aggregation was normal in these children. Decreased or absence of platelet dense granules by TEM study was detected in some patients. These changes in platelet functions and morphology may be due to acquired storage pool deficiency of the platelet. Parasitic infection was detected in 56% of these children. About 83% of these children with APDE had serum total IgE higher than 100 IU/ml. There was no correlation between the number of eosinophils and serum total IgE and the severity of bleeding symptoms. The majority of children with APDE did not receive any treatment except those who had severe bleeding symptoms which required platelet concentrate to stop bleeding. In more than 90% of the patients, the bruising or ecchymosis disappeared within 6 months and the abnormal platelet functions returned to normal within 4 months. Recurrence of these bleeding syndromes was detected in 7% of the children.

Clinical and hematologic features of beta0-thalassemia (frameshift 41/42 mutation) in Thai patients.

BACKGROUND AND OBJECTIVES: Frameshift 41/42 mutation is the most common mutation of beta0-thalassemia found in Thailand. We studied clinical and hematologic features in 84 patients and relatives with frameshift 41/42 to determine whether it is possible to predict phenotypic severity from genetic factors. DESIGN AND METHODS: The clinical phenotypes and hematologic data of Thai patients with frameshift 41/42 were studied. Alpha-thalassemia, Hb Constant Spring (HbCS) genes and the presence of Xmnl-Ggamma polymorphism were studied in patients who had mild symptoms. RESULTS: Homozygotes for frameshift 41/42 and compound heterozygotes for frameshift 41/42 and beta0-thalassemia produced severe symptoms and have a thalassemia major phenotype. Combination of frameshift 41/42 and beta0-thalassemia or Hb E produced mild to moderate symptoms with thalassemia intermedia phenotype and severe symptoms with thalassemia major phenotype. The co-inheritance of beta-thalassemia or HbCS gene or the presence of Xmnl-Ggamma polymorphism was not associated with mild disease in patients with frameshift 41/42 and HbE. INTERPRETATION AND CONCLUSIONS: The clinical phenotype of homozygotes for frameshift 41/42 and compound heterozygotes for frameshift 41/42 and beta0-thalassemia could be used to predict a severe phenotype with thalassemia major. However, the clinical phenotype of compound heterozygotes of frameshift 41/42 and beta0-thalassemia or Hb E were variable and could not be accurately predicted. Associations between concomitant alpha-thalassemia or HbCS of the presence of Xmnl-Ggamma polymorphism and a mild clinical phenotype are not apparent, indicating the involvement of other ameliorating determinants or genetic modifications.

Clinical and hematological features of codon 17, A-T mutation of beta-thalassemia in Thai patients.

Forty-one patients with codon 17, A-T mutation of beta-thalassemia, which is commonly found in Thailand, were studied to determine whether it is possible to predict phenotypic severity from genetic factors. The clinical phenotype of homozygotes for codon 17, A-T and compound heterozygotes for codon 17, A-T and beta+-thalassemia may be used to predict a severe phenotype with TM. However, the clinical phenotype of compound heterozygotes for codon 17, A-T and beta+-thalassemia or Hb E were variable and could not be accurately predicted. The association of alpha-thalassemia2 and milder disease was and was not evident in patients with codon 17, A-T and Hb E. The association between Hb CS gene or the presence of XmnI-Ggamma polymorphism and a mild clinical phenotype is not apparent, indicating the involvement of other ameliorating determinants or genetic modifications.