Common origin of a rare beta-globin initiation codon mutation (ATG-->AGG) in Asians.

In this report, we describe two Thai siblings presenting with mild hypochromic microcytic anaemia and splenomegaly since 2(1/2) years of age. However, both patients were otherwise well with normal weight and height development and did not require transfusion during the 6-year follow-up period. Haematological and haemoglobin analyses were consistent with the clinical diagnosis of Hb E/beta-thalassaemia disease. To provide proper genetic counselling for this family, a definitive diagnosis of beta-thalassaemia was achieved using molecular analysis. We identified a rare initiation codon mutation (ATG-->AGG) of the beta-globin gene in combination with the Hb E mutation (codon 26: GAG-->AAG). The initiation codon mutation has previously been reported in several East Asian populations but has never been found in Southeast Asia and in combination with Hb E before. The haplotype analysis revealed a common origin of this mutation in the Asian population (5': - + - + + - +: 3', type IV with framework 3 according to Orkin S, et al.). Although this rare mutation abolished the beta-globin expression and was considered as beta(0)-thalassaemia, the relatively mild phenotype in our patients may be attributed to a strong association between this mutation and the -158 (G)gamma (C-->T) polymorphism, an XmnI cleavage site (+), resulting in a high propensity of postnatal gamma-globin expression and ameliorating the clinical phenotypes.

Linear growth in homozygous beta-thalassemia and beta-thalassemia/hemoglobin E patients under different treatment regimens.

The effects on linear growth and development among thalassemic patients under different treatment regimens were compared. Twelve homozygous beta-thalassemia (homozygous beta-thal) and 36 beta-thalassemia/Hb E (beta-thal/Hb E) were studied longitudinally between 1977 and 1998. Eighteen cases (10 homozygous beta-thal and 8 beta-thal/Hb E) received hypertransfusion with iron chelation by desferrioxamine. Another 30 cases (2 homozygous beta-thal and 28 beta-thal/Hb E) were given a low transfusion (depending on their clinical requirement). Their heights were measured serially and are presented as a standard deviation score (SDS). There was no significant difference in initial basic hematological data and ferritin levels between either group. However, the hypertransfused group, seemed to be clinically more severely affected than the other group as evidenced by early age at initial transfusion, the early onset of anemia and diagnosis and also their large acquired iron load after a period of transfusion. The average height SDS of the hypertransfused patients was within the 50th percentile +/- 1 SD during the first decade of life in both sexes and both genotypes. Whereas, in patients who were transfused infrequently, the SDS was always below the -1 SD and decreased gradually. In severe beta-thal/Hb E cases, their growth SDS showed no difference from those with homozygous beta-thal. Normal linear growth in those with homozygous beta thal and severe beta-thal/Hb E was only seen in the group that underwent hypertransfusion and this regimen contributed to normal growth during the first ten years of life. However, adequate iron chelation and hormonal treatment in these patients were also required in order to achieve normal adult height.

Successful bone marrow transplantation in a child with red blood cell pyruvate kinase deficiency.

We report the first successful use of BMT for the treatment of RBC pyruvate kinase (PK) deficiency in a boy who developed neonatal jaundice and severe transfusion-dependent hemolytic anemia a few months after birth. He received a BMT at the age of 5 from an HLA-identical sister who has normal PK activity after conditioning with busulfan and cyclophosphamide. The post-transplant course was uneventful. At present, 3 years after transplant, he is 8 years old and has a normal hemoglobin level and normal RBC PK activity without evidence of hemolysis. DNA analysis has confirmed full engraftment.

Purification of human hemopoietic stem cells for transplantation in Thailand.

Stem cell transplantation (SCT) has become the therapy of choice for many hematologic and immunologic disorders. At present, only 25% of patients have suitable HLA-identical donors. In an attempt to increase the donor pool for SCT in Thailand and Southeast Asia, we developed a program whereby parents and mismatched siblings can be used as donors. In this preliminary study, after granulocyte-colony-stimulating factor (G-CSF) was given to adult donors, peripheral blood stem cells (PBSC) were collected and CD34+ cells purified using a CliniMACS immunomagnetic device (Miltenyi Biotec, Germany). In seven experiments, purified CD34+ cells could be obtained from G-CSF-stimulated PBSC in large numbers (1.71 +/- 0.19 x 10(8)), with high purity (93 +/- 2.4%) and excellent recovery (64.28% - 85.62%). Immune reactive T and NK cells were adequately depleted to less than 0.2%. The purification procedure can be completed within 3 hours. In conclusion, a clinical stem cell purification program using this novel device is now established in Thailand and for the first time in Southeast Asia. This should allow further development of advanced SCT therapy including haploidentical and mismatched CD34+ SCT for patients' lacking HLA-identical donors in this region.

Compound heterozygosity for one novel and one recurrent mutation in a Thai patient with severe protein S deficiency.

Homozygous or compound heterozygous protein S (PS) deficiency is a very rare disorder in the anticoagulant system, that can lead to life-threatening thrombotic complications shortly after birth. This report describes the results of the genetic analysis of the PROS 1 genes in a Thai girl patient. She was reported in 1990 as the first case with homozygous PS deficiency and neonatal purpura fulminans. In the present report, we identified the mutations in this patient by direct sequencing of PCR products representing all 15 exons of the PROS 1 gene and their flanking intronic regions. The patient turned out to be compound heterozygous for two null mutations. One allele contained a novel sequence variation, an A-insertion in an A5-tract covering codon 146 and 147, that results in a frameshift and a stop codon (TAA) at position 155. The other allele contained a nonsense mutation in exon 12 by a transition at codon 410 CGA (Arg) to TGA (stop). Cosegregation of PS deficiency with these two genetic defects was observed in her family.

Gaucher's disease;thirty-two years experience at Siriraj Hospital.

Gaucher's disease, a lysosomal disorder, is not a common disease in Thailand. During the period 1966-1998 we saw 20 patients with Gaucher's disease at the Department of Pediatrics. Siriraj Hospital. The patients came from different regions of the country but mostly from the central part of Thailand. There were 8 males and 12 females from 13 families of Thai, Thai-Chinese, Thai-Laos and Chinese-Chinese in origin. A history of consanguinity was present in 2 families. The age of onset was 2 months-4 years and the age when they were diagnosed was 4 months-15 years. The most common clinical features included splenomegaly, hepatomegaly, growth retardation, pallor, bleeding disorders and neurological abnormalities. The diagnosis was made by the clinical manifestations, hematologic complications and demonstration of Gaucher cells in the bone marrow and/or other tissues. In one family, the diagnosis was confirmed by evaluation of glucocerebrosidase activities in skin fibroblasts. The management of these patients was symptomatic ie packed red cell and platelet transfusion, splenectomy and other supportive measures. Most patients died of bleeding or infection at an early age.

Glucose-6-phosphate dehydrogenase deficiency in Thailand; its significance in the newborn.

The prevalence of G6PD deficiency in Thai males ranges from 3-18% depending upon the geographic region. G6PD "Mahidol" (163 Gly --> Ser) is the most common variant found in the Thai population. Almost all affected Thai individuals are not anemic and are asymptomatic. Severe acute intravascular hemolysis is occasionally seen, for instance, in those cases who have a viral infection, bacterial infection or have been exposed to chemicals or drugs. In Thailand, diagnosis of G6PD deficiency is usually made only in symptomatic cases. Neonatal screening of G6PD deficiency is not practiced nationwide, though studies have been done in several institutes. The assessment of G6PD activity in the newborn is mostly in order to find out the cause of neonatal jaundice. In our experience and that of others. G6PD deficient newborns are more prone to develop neonatal jaundice which is, on its own, no more severe than jaundice from other causes. Kernicterus due to G6PD deficiency, though still seen, is now very rare. Awareness of the hazard of hyperbilirubinemia, whatever the cause, along with active management is needed to prevent the occurrence of kernicterus. Neonatal screening is useful to detect abnormalities in the newborn. Weighing of the cost and benefit of neonatal screening should be made and the families of patients should be offered proper education and counseling to help them understand their babies' condition.

Prevalence of HB E from cord blood samples and after one year follow-up.

Hemoglobin (Hb) E is the most prevalent hemoglobinopathy in Southeast Asia. The prevalence of this condition varies from 9-60% of the population in different regions of Thailand and has the highest prevalence the northeast of the country. Neonatal diagnosis of Hb E can be made by detecting the Hb band in cord blood samples at the Hb A2 position using starch gel and cellulose acetate electrophoresis. Our study, performed in Bangkok, in the central part of Thailand, resealed that 182 out of 1,015 cord blood samples (17.9%) contained Hb E in amounts of between 1.9 and 10.0%. The cases who had Hb A, F and E with or without Hb Bart's were initially included in the study. These cases were suspected to have the Hb E trait. One hundred and seven cases (58.89%) were available for follow up and in all of these, Hb E could be detected throughout the study. A sharp increase in the amount of Hb E was observed at the 3 months follow-up appointment. One year follow-up could be made in 72 cases (39.6%) when the percentage of Hb E was around 25%. We conclude that measurement of Hb E in cord blood an easily accessible, simple, practical and sensitive procedure which can be used to study the Hb E hemoglobinopathy which is widely distributed in Thailand and Southeast Asia.

Novel AE1 mutations in recessive distal renal tubular acidosis. Loss-of-function is rescued by glycophorin A.

The AE1 gene encodes band 3 Cl-/HCO3- exchangers that are expressed both in the erythrocyte and in the acid-secreting, type A intercalated cells of the kidney. Kidney AE1 contributes to urinary acidification by providing the major exit route for HCO3- across the basolateral membrane. Several AE1 mutations cosegregate with dominantly transmitted nonsyndromic renal tubular acidosis (dRTA). However, the modest degree of in vitro hypofunction exhibited by these dRTA-associated mutations fails to explain the disease phenotype in light of the normal urinary acidification associated with the complete loss-of-function exhibited by AE1 mutations linked to dominant spherocytosis. We report here novel AE1 mutations linked to a recessive syndrome of dRTA and hemolytic anemia in which red cell anion transport is normal. Both affected individuals were triply homozygous for two benign mutations M31T and K56E and for the loss-of-function mutation, G701D. AE1 G701D loss-of-function was accompanied by impaired trafficking to the Xenopus oocyte surface. Coexpression with AE1 G701D of the erythroid AE1 chaperonin, glycophorin A, rescued both AE1-mediated Cl- transport and AE1 surface expression in oocytes. The genetic and functional data both suggest that the homozygous AE1 G701D mutation causes recessively transmitted dRTA in this kindred with apparently normal erythroid anion transport.

Malignant lymphoma in Thailand: changes in the frequency of malignant lymphoma determined from a histopathologic and immunophenotypic analysis of 425 cases at Siriraj Hospital.

BACKGROUND: Analysis of malignant lymphoma in a single institution at different periods of time can determine the changing status of the disease in the region. METHODS: To compare with the large series of 1095 lymphoma cases reported between 1957-1971 at Siriraj Hospital, the largest hospital in Thailand, a similar study was performed through histopathologic evaluation of 425 lymphoma cases diagnosed consecutively at the same institution between August 1993 and October 1995. Phenotypic analysis was performed by paraffin section-immunoperoxidase studies. RESULTS: A striking increase in lymphoma cases was noted from 73 cases/year in the first series to 189 cases/year in the second series (an increase of 158.9%). Lymphoma occurred in all age groups, with a peak incidence at the seventh decade of life. The male to female ratio decreased from 2:1 in 1957-1971 to 1.3:1 in the more recent series. The incidence of Hodgkin's disease (HD) was found to have decreased from 28.9% to 8.5%. There were 36 cases (8.5%) of HD and 389 cases (91.5%) of non-Hodgkin's lymphoma (NHL) reported in the second series. The subtypes of HD included 16 cases of mixed cellularity, 13 cases of nodular sclerosis, 6 cases of lymphocyte depletion, and 1 case of lymphocyte predominance. According to the Working Formulation, the 389 NHL cases included low grade (14.1%), intermediate grade (57.3%), high grade (11.3%), and miscellaneous groups (17.2%). They were classified as small lymphocytic (9.5%), follicular (11.1%), diffuse (50.9%), immunoblastic (4.1%), small noncleaved (4.4%), lymphoblastic (2.8%), anaplastic large cell (9.0%), mycosis fungoides (1.8%), hairy cell leukemia (0.3%), true histiocytic (0.5%), and extramedullary plasmacytoma (1.0%). The immunophenotypes of the 359 NHL cases available for paraffin section-immunoperoxidase studies were B-cell (71.0%), T-cell (24.5%), histiocyte (0.6%), and undetermined phenotypes (3.9%). CONCLUSIONS: The incidence of malignant lymphoma is increasing in Thailand, with a high frequency of intermediate to high grade NHL of B-cell phenotype reported.

Renal tubular function in beta-thalassemia.

Studies of the renal involvement in thalassemic syndromes have been varied and few. This study was designed to define the renal abnormalities associated with beta-thalassemia and to correlate the renal findings with clinical parameters. One hundred and four beta-thalassemic children with various disease severity were studied. The patients were divided into three groups: 48 with severe anemia [hematocrit (Hct) < 25%], 31 on a hypertransfusion program and desferrioxamine treatment, and 25 with moderate anemia (Hct > 25%). The results were compared with 15 normal children. Significantly higher levels of proteinuria and low molecular weight proteinuria were found in all patients compared with normal children. Aminoaciduria was detected in one-third of patients. Thalassemic patients had significantly lower morning urine osmolarity, higher urine N-acetyl-beta-D-glucoseminidase and malondialdehyde (MDA, an indicator of lipid peroxidation). Patients with severe anemia had significantly higher low-molecular weight proteinuria and MDA, and lower urine osmolarity than those with moderate anemia. Our data confirmed the high frequency of renal abnormalities in beta-thalassemia patients and indicated some degree of proximal tubular dysfunction. Severity of the abnormalities correlated with the degree of anemia and were least severe in patients on hypertransfusion and desferrioxamine therapy. This suggested that the damage might be caused by anemia and increased oxidation induced by excess iron deposits.

Bone marrow, peripheral blood and cord blood stem cell transplantation in children: ten years' experience at Siriraj Hospital.

Stem cell transplantations were performed in 69 children at Siriraj Hospital over a ten year period. The source of stem cells was bone marrow (60), peripheral blood (3), or cord blood (6). The diseases treated included 35 thalassemias, 11 Burkitt's lymphoma, five non-Hodgkin's lymphoma, five aplastic anemia, eight acute leukemia, and one each of neuroblastoma, severe combined immunodeficiency, Wiskott-Aldrich syndrome, myelodysplastic syndrome, and pyruvate kinase deficiency. The success rate of stem cell transplantation in Thai children varied according to the underlying diseases of the patients, ranging from 50% in acute leukemia to 100% in aplastic anemia. The outcome of stem cell transplantation in 35 thalassemic children revealed 23 (79.4%) were cured, whereas three (10.3%) remain alive with disease and the other three (10.3%) died. The incidence of graft-versus-host disease was low hen compared with that of Western countries. It is concluded that bone marrow, peripheral blood and cord blood stem cell transplantation will be the treatment of choice and will be widely used in the future to cure many hematologic and malignant disorders in children.

Molecular basis of hereditary methaemoglobinaemia, types I and II: two novel mutations in the NADH-cytochrome b5 reductase gene.

Hereditary methaemoglobinaemia, caused by deficiency of NADH-cytochrome b5 reductase (b5R), has been classified into two types, an erythrocyte (type I) and a generalized (type II). We analysed the b5R gene of two Thai patients and found two novel mutations. The patient with type II was homozygous for a C-to-T substitution in codon 8 3 that changes Arg (CGA) to a stop codon (TGA), resulting in a truncated b5R without the catalytic portion. The patient with type I was homozygous for a C-to-T substitution in codon 178 causing replacement of Ala (GCG) with Val (GTG). To characterize effects of this missense mutation, we investigated enzymatic properties of mutant b5R (Ala 178 Val). Although the mutant enzyme showed normal catalytic activity, less stability and different spectra were observed. These results suggest that this substitution influenced enzyme stability due to the slight change of structure. In conclusion, the nonsense mutation led to type II because of malfunction of the truncated protein. On the other hand, the missense mutation caused type I, due to degradation of the unstable mutant enzyme with normal activities in patient's erythrocytes, because of the lack of compensation by new protein synthesis during the long life-span of erythrocytes.

Pyruvate kinase deficiency in an alpha-thalassemia family: first case report in Thailand.

In Thailand, the most common cause of chronic hemolytic anemia is thalassemia hemoglobinopathy. We report here a 10-year-old girl with pyruvate kinase (PK) deficiency who was initially diagnosed to have Hb H disease, like her sister. The patient had a history of neonatal jaundice which required blood exchange transfusion twice and phototherapy. She became anemic and regular blood transfusion was required since the age of 2 1/2 months. She was very anemic compared to her sister and was transfusion dependent. Besides, she never had red cell inclusion bodies, thus re-evaluation was performed. The diagnosis of red cell pyruvate kinase deficiency and the exclusion of Hb H disease was achieved after cessation of blood transfusion for 3 months. The family study also confirmed the diagnosis. The patient is now on high transfusion and iron chelation. She is doing well with mild splenomegaly.

Difference in pattern of erythropoietin response between beta-thalassemia/hemoglobin E children and adults.

Thalassemia is one of the most common genetic disorders in Thailand. The thalassemic patients have many pathophysiologic changes secondary to chronic anemia. During these last few years there have been many trials to cure or improve the anemic condition in thalassemia by using various agents, including erythropoietin (EPO). Thus it is very important to understand the EPO response to different degree of anemia in the thalassemic patients. In this study we evaluated the EPO status in 53 beta-thalassemia/HbE patients, from 4-61 years old, by enzyme-linked immunosorbent assay. The results showed that the levels of EPO in beta-thalassemia/HbE patients were much higher than in normal control subjects: mean +/- SE = 527 +/- 183.20 and 3.45 +/- 0.47 mIU/ml respectively. The reverse correlation between the levels of EPO and hematocrit (r = -0.704) was also observed. There was also a tendency to have higher levels of EPO in beta-thal/HbE children than in adults, although this was statistically insignificant. The observed versus predicted levels of EPO (log O/P ratio) showed that most patients had good EPO response to the degree of anemia. However, inappropriate decrease of EPO response was observed in 8/40 adult patients. The EPO levels in these patients were not correlated with any physical or laboratory studies, including kidney function. We thus propose that if EPO is to be considered as one of the alternative treatment to the thalassemic patients, in the future, it may benefit only the patients with low EPO levels.

Successful treatment of cytophagic histiocytic panniculitis by cyclosporin A: a case report.

This is a report of a case, 7 1/2 year-old-boy having chronic febrile and recurrent crops of painful subcutaneous nodules on lower extremities, which had previously been diagnosed as Weber-Christian disease, which progressed to have cytophagic histiocytic activity in the skin, bone marrow with abnormal liver function and hemorrhagic diathesis. He was subsequently treated with corticosteroid without good response. After he was diagnosed as having cytophagic histiocytic panniculitis, cyclosporin A was administered intravenously in an initial dosage of 1 mg/kg/day and in oral maintenance dose of 10 mg/kg/day with a successful response and the patient completely recovered within 6 months with mild hypertension as an adverse effect.