Genotype and phenotype of haemophilia A in Thai patients.

To study genotype and phenotype correlation of haemophilia A in Thai patients, molecular defects of the factor VIII (FVIII) gene were examined and their correlation with clinical phenotypes were evaluated. The molecular pathologies of FVIII in Thai patients were found to be heterogeneous. The most common mutation was FVIII intron 22 inversion accounting for about 30% of the severe cases while gene deletion was rare. Sixteen point mutations were identified, comprising two nonsense mutations (R-5X and R1966X), five missense mutations (T233I, D542Y, G1850V, W2229S and G2325C), five nucleotide deletions (1145delT, 1187-8delACAC, 1191-4delA, 1458delGA and 1534delA), three nucleotide insertions (1439-41insA, 1934insTA and 2245insACTA) and one splicing defect (IVS15+1G>T). Nine mutations (T233I, D542Y, 1145delT, 1458delGA, 1534delA, 1934insTA, W2229S, 2245insACTA and G2325C) were novel, firstly identified in Thai patients. The genotypes were found to correlate with clinical phenotypes in a majority of cases. However, in five patients the molecular defects did not correlate with clinical severity and FVIII:C level. Cellular and molecular mechanisms were proposed to be responsible in amelioration of clinical severity caused by deleterious mutations. Carrier detection by direct mutation analysis was also demonstrated.

Penicilliosis-associated hemophagocytic syndrome in a human immunodeficiency virus-infected child: the first case report in children.

Infection-associated hemophagocytic syndrome (IAHS) has been found in many systemic infectious conditions with a high mortality rate. Disseminated Penicillium marneffei infection is a common opportunistic condition among HIV-infected patients in many regions in Southeast Asia. We report the first case of IAHS caused by penicilliosis in an HIV-infected child who presented with cytopenias and recovered promptly after antifungal and intravenous immunoglobulin therapy.

Mutation causing exon 15 skipping and partial exon 16 deletion in factor VIII transcript, and a method for direct mutation detection.

A splicing defect with 201 nucleotide deletion in the factor VIII transcript due to IVS15 + 1G > T mutation inactivating this donor splice site and activating a cryptic acceptor splice site in exon 16 was identified in a severe haemophilia A patient. Allele specific amplification (ASA) method was successfully developed for direct detection of this mutation.

Neonatal alloimmune thrombocytopenia due to anti-Nak(a).

BACKGROUND: The accurate diagnosis of neonatal alloimmune thrombocytopenia is essential in the effective treatment of potentially serious bleeding in neonates. CASE REPORT: Reported here is a case of a full-term female baby who was delivered by vacuum extraction from a gravida 1 para 1 healthy mother. She presented with generalized petechiae and bilateral cephalhematoma, which she had had since birth. At 7 hours of life, she had an upper gastrointestinal hemorrhage and was found to have severe anemia and marked thrombo-cytopenia. Coagulation screening tests were normal. The diagnosis of neonatal alloimmune thrombocytopenia was suspected, and maternal serum was collected for further study. The baby was treated with a single dose of hydrocortisone (10 mg/kg) and IVIG (400 mg/kg) while waiting for irradiated platelets from her mother. After 30 mL of a transfusion of maternal platelets, the baby's platelet count rose dramatically, from 15,000 to 162,000 per microL, and it remained stable at that level. She was discharged on the 10th hospital day in good condition. During the follow-up period of 8 months, her growth and development were satisfactorily normal, as well as her platelet count. A high-titered platelet antibody was detected in the maternal serum by use of a solid phase platelet adherence technique. RESULTS: The specificity of the platelet antibody was identified as anti-Nak(a) by the mixed passive hemagglutination test method. CONCLUSION: These findings suggested a diagnosis of NAIT caused by anti-Nak(a).

Determination of haemophilia A carrier status by mutation analysis.

A reliable method for determination of carrier status and genetic counselling is required for effective control of haemophilia. Linkage analysis is currently the most widely used method for this purpose; however, in cases where there is no prior family history and/or unavailability of informative polymorphic markers it is less applicable. Detection of a mutation characterized in each family may be an alternative method for determination of the carrier status. In this study, linkage analysis using four polymorphic DNA markers, and direct mutation analysis were compared to determine the carrier status in six unrelated Thai haemophilia A families, two with a family history and four without. In the two families with a family history of haemophilia A, the carrier and noncarrier statuses could readily be determined in eight females by either linkage or direct mutation analysis. In the four families without a family history, the polymorphic DNA markers for linkage analysis were informative in two families and uninformative in the other two. The carrier status could be excluded in all four female siblings of the patients in the former. However, the specific FVIII gene mutation was not observed in the mother of one patient, who should have carried the mutation. In the remaining two families with uninformative polymorphic DNA markers, the carrier and noncarrier statuses of four female members could only be determined by direct mutation analysis. Therefore, direct mutation analysis could circumvent the limitations of linkage analysis in the determination of haemophilia A carrier status in families without a previous history or informative polymorphic markers.

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.

Frameshift mutations with severe and moderate clinical phenotypes in Thai hemophilia A patients.

Six frameshift mutations in exon 14 of the factor VIII gene were identified in Thai hemophilia A patients. Although all these mutations created premature stop codons and expected to cause severe disease, the molecular defects and clinical severity were in discrepancy in some patients. Four mutations (delT3490, delACAC3618-21, delGA4429-30, and delA4658) were found in the patients with the severe clinical phenotype while two (delA3629-37 and insA4372-9) were observed in the patients who had moderate severity, with FVIII:C of 4.2 and 2.8%. The frameshift mutations in these two patients were due to deletion and insertion of an 'A' nucleotide in the stretches of 9As and 8As in codons 1191-4 and 1439-41, respectively. This indicates that deletion or insertion in the stretches of poly A nucleotides in exon 14 of the factor VIII gene is a likely cause of the moderate clinical severity in some cases of Thai hemophilia A patients.

Successful prophylaxis of intracranial hemorrhage in infants with severe congenital factor VII deficiency.

During the period 1984-1992, 2 severe cases (1 male, 1 female) of congenital F VII deficiency with intracranial hemorrhage (ICH) were referred to the Department of Pediatrics, Siriraj Hospital Bangkok, Thailand at the ages of 1 and 3 months old. They both responded very well to fresh frozen plasma (FFP) transfusion therapy. Subsequently, both had repeated episodes of ICH (repeated ICH) 5 and 6 times, despite the 10-14 days of replacement therapy for each episode and eventually died at the ages of 11 and 13 months. Since September 1996, another 2 severe cases (2 females) of congenital F VII deficiency who had ICH within their first month of life were referred to us. In order to prevent repeated ICH, we started a prophylactic regime after the second episode of ICH, by giving FFP 10 ml/kg twice a week. The average duration of follow up was 21 months (at 8 and 34 months). All of them (aged 14, and 38 months old) are doing well at this time and free from repeated ICH. From this observation, if there is FFP available, this regime is an effective way to prevent repeated ICH in infants with severe congenital Factor VII deficiency.

What is the sudden death syndrome in Southeast Asian males?

Sudden unexplained death syndrome describes the death of apparently healthy individuals--usually young men--in whom postmortem examination does not reveal the cause of death. The victims are in apparently good health and usually die at night while sleeping. They die within minutes after the onset of agonal respiration. Patients who have been resuscitated were found to have ventricular fibrillation and inducible polymorphic ventricular tachycardia in the electrophysiologic laboratory. This syndrome has been most frequently described in young Southeast Asian men. In this review, the epidemiology, clinical and electrophysiologic manifestations, pathology and risk factors, prognosis, and treatments for sudden unexplained death syndrome are described.

Mutations of the factor VIII gene in thai hemophilia A patients.

Hemophilia A is a common X-linked bleeding disorder caused by mutations in the coagulation factor VIII gene. The entire coding and essential sequences of the factor VIII gene were generated by a combination of genomic DNA amplification and long reverse transcription-polymerase chain reaction (long RT-PCR) using factor VIII transcripts prepared from lymphocytes. Mutations were then screened by non-radioactive single strand conformation polymorphism (SSCP) analysis and characterized by DNA sequencing. We have identified six potentially pathogenic mutations in the factor VIII gene in Thai hemophilia A patients, including two nonsense mutations (R-5X and R1966X), three missense mutations (D542Y, G1850V, and G2325C), and a 4-bp insertion (ACTA) at codon 2245. Three of these mutations (D542Y, G2325C, and 4-bp insertion) have never been previously reported, and the ins2245 is the first example of such insertion probably causing factor VIII elongation. R1966X, D542Y, G1850V, and 4-bp insertion were associated with a severe hemophiliac phenotype whereas R-5X and G2325C were observed in moderately affected patients. Mutations in the factor VIII gene in Thai hemophilia A patients are likely to be heterogeneous. This study represents the first attempt to further the understanding of the molecular basis of hemophilia A in Thai.

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.

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.

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.

Arrhythmogenic marker for the sudden unexplained death syndrome in Thai men.

BACKGROUND: Between 1981 and 1988, the Centers for Disease Control and Prevention reported a very high incidence of sudden death among young male Southeast Asians who died unexpectedly during sleep. The pattern of death has long been prevalent in Southeast Asia. We carried out a study to identify the clinical markers for patients at high risk of developing sudden unexplained death syndrome (SUDS) and long-term outcomes. METHODS AND RESULTS: We studied 27 Thai men (mean age, 39.7+/-11 years) referred because they had cardiac arrest due to ventricular fibrillation, usually occurring at night while asleep (n=17), or were suspected to have had symptoms similar to the clinical presentation of SUDS (n=10). We performed cardiac testing, including EPS and cardiac catheterization. The patients were then followed at approximately 3-month intervals; our primary end points were death, ventricular fibrillation, or cardiac arrest. A distinct ECG abnormality divided our patients who had no structural heart disease (except 3 patients with mild left ventricular hypertrophy) into two groups: group 1 (n=16) patients had right bundle-branch block and ST-segment elevation in V1 through V3, and group 2 (n=11) had a normal ECG. Group 1 patients had well-defined electrophysiological abnormalities: group 1 had an abnormally prolonged His-Purkinje conduction time (HV interval, 63+/-11 versus 49+/-6 ms; P=.007). Group 1 had a higher incidence of inducible ventricular fibrillation (93% for group 1 versus 11% for group 2; P=.0002) and a positive signal-averaged ECG (92% for group 1 versus 11% for group 2; P=.002), which was associated with a higher incidence of ventricular fibrillation or death (P=.047). The life-table analysis showed that the group 1 patients had a much greater risk of dying suddenly (P=.05). CONCLUSIONS: Right bundle-branch block and precordial injury pattern in V1 through V3 is common in SUDS patients and represents an arrhythmogenic marker that identifies patients who face an inordinate risk of ventricular fibrillation or sudden death.

Itraconazole for treatment of oral candidosis in pediatric cancer patients.

Oral candidosis commonly occurs in malignancy children undergoing antineoplastic chemotherapy. Inadequate response to antifungal treatment leads to a risk of disseminated infection. The aim of this study is to evaluate the efficacy and side effects of itraconazole on treatment of oral candidosis. Fourteen children with malignancy undergoing chemotherapy received itraconazole 100-200 mg/day for 10 days to treat oral candidosis. The severity of disease was defined as mild and moderate depending on the number of lesions and symptoms. Oropharyngeal lesions and symptoms were recorded initially and daily. Blood chemistries were done on day 0, day 10 and day 16. The overall response rate was 87.5 per cent. The mild group (4 cases) had a response rate of 100 per cent which had lesions and symptoms resolved on day 2 and day 1.5 +/- 0.7 respectively. The moderate group (10 cases) had 8 responders (80%) whose lesions and symptoms resolved on day 6 +/- 2.5 and day 4.1 +/- 2.3 respectively. Side effects and abnormal blood chemistry values. were not seen.

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.