Response to Prolonged Duration of Therapeutic Dose Oral Iron Therapy in a Girl With Novel TMPRSS6 Gene Variants: A Case Report and Review Literature.

Iron-refractory iron deficiency anemia (IRIDA) is an autosomal recessive disorder caused by mutations in the TMPRSS6 gene, which impair iron homeostasis. We reported a 4-year-old girl who presented with a 1-year history of iron deficiency anemia. Her hemoglobin level increased from 6.5 g/dL to 12.6 g/dL with a prolonged duration of therapeutic dose oral iron therapy (5 mg/kg/d), and the level remained quite stable during the therapy. Genetic analysis of the TMPRSS6 gene revealed compound heterozygotes of 2 novel pathogenic variants: c.811C> T (NM_153609.3) in exon 7 (NP_705837: p.R271Ter) and c.1254C> G in exon 11 (p.Y418Ter). The results highlight the significance of genetic investigation and long-term iron therapy in iron-refractory iron deficiency anemia patients.

Screening for ELANE, HAX1 and GFI1 gene mutations in children with neutropenia and clinical characterization of two novel mutations in ELANE gene.

BACKGROUND: Congenital neutropenia is a rare disease. Recurrent infections since young age are the presentation. The most common mutation causing severe congenital neutropenia (SCN) and cyclic neutropenia (CyN) is the ELANE gene. The objectives of this study were to screen the three common genetic mutations of ELANE, HAX1 and GFI1 in children with chronic neutropenia and to describe the clinical characteristics of children who had the mutations. METHODS: Infants having ANC < 1,000/cu mm or children aged > 1 year having ANC < 1,500/cu mm at least 3 times in 3 months were enrolled in the study. Patients who had acquired neutropenia due to infection, immune deficiency, or drugs were excluded. The ELANE gene was first studied; and if mutations were not identified, the HAX1 and GFI1 genes were further examined. RESULTS: A total of 60 patients were enrolled in the study. The median (range) age, ratio of female to male, ANC, and last follow-up age were 9.2 (0.5-45.2) months, 1:1.2, 248 (0-1,101) /cu mm, and 19.9 (3.5-202.3) months, respectively. Infections were noted in 67.3% of all patients. ELANE gene mutation was found in only four patients (6.7%), and the rest (56 patients) showed no mutations in the HAX1 and GFI1 genes. In patients without mutations, 66.0% had normal ANC during the follow-up, with a median (range) age for normal ANC of 19.8 (4.0-60.0) months. Two novel mutations p. Ala79del (c.234_236del) and p. Val197GlufsTer18 (c.589_590insAGGCCGGC) were identified, and they respectively cause SCN and CyN. Patients with the two novel mutations presented with several episodes of infection, including pneumonia, sepsis, abscess, otitis media, and gum infection. CONCLUSION: The genetic screening for ELANE, HAX1, and GFI1 gene mutations in 60 patients with chronic neutropenia could identify four patients (6.7%) with ELANE gene mutation and two novel mutations, p. Ala79del in exon 3 and p. Val197GlufsTer18 in exon 4 causing SCN; and CyN, respectively.

Whole-exome sequencing uncovered genetic diagnosis of severe inherited haemolytic anaemia: Correlation with clinical phenotypes.

Next-generation sequencing has shed light on the diagnosis of previously unsolved cases of inherited haemolytic anaemia (IHA). We employed whole-exome sequencing to explore the molecular diagnostic spectrum of 21 unrelated Thai paediatric patients with non-thalassemic IHA, presenting hydrops fetalis and/or becoming transfusion-dependent for 1 year or more or throughout their lifespan. Anaemia was detected prenatally, within the first month and the fifth year of life in three, 12 and six patients respectively. Molecular diagnosis obtained from all patients revealed SPTB as the most frequently mutated gene (four reported, three novel), found in 31 of 42 studied alleles. The other two mutated genes identified were ANK1 (three novel) and KLF1 (two reported). Four recurring mutations within exon 29/30 (NM_001024858.2) accounted for the vast majority (90%) of mutated SPTB alleles, biallelic inheritance of which resulted in the most severe phenotypes: hydrops fetalis and life-long transfusion dependency. Dominant ANK1 (n = 3) and SPTB (n = 2) mutations and biallelic class 2 KLF1 mutations (n = 1) led to a shorter period of transfusion dependency. Our study demonstrated that mutated SPTB causing red-cell membranopathy is likely the most common cause of severe non-thalassemic IHA among Thai patients. This urges carrier screening in the population to prevent subsequent, severely affected births.

The Effect of Blood Transfusion on Growth of Patients with Hb E/ß-Thalassemia.

A retrospective evaluation of growth in 112 patients (68 males, 44 females) with Hb E (HBB: c.79G>A)/ß-thalassemia (ß-thal), classified as 88 transfusion-dependent thalassemia (TDT) and 24 non transfusion-dependent thalassemia (NTDT), is reported. Patients with TDT have received regular transfusions of red blood cells (RBCs) 15 mL/kg every 4 weeks to maintain pre transfusion hemoglobin (Hb) levels of at least 9.0 g/dL and were categorized according to age at initiation of regular RBC transfusion as subgroup 1, <4 years; subgroup 2, 4-10 years, and subgroup 3, >10 years. Iron chelation was initiated at the mean age of 7 years. The results revealed that patients in subgroups 1 and 2, receiving RBC transfusions at a young age (2.9 and 6.9 years, respectively), had normal prepubertal growth at enrollment and last follow-up. Patients in subgroup 3, with the lowest initial height Z-score of -2.10, were able to achieve comparable final adult height as those in subgroups 1 and 2. The mean final height of 21 males and 13 females with TDT at the ages of 18.9 and 18.7 years was 168.1 and 157.7 cm, respectively, which did not significantly differ from their midparental height and those with NTDT. Early initiation of optimal transfusion and iron chelation promoted normal prepubertal growth. However, delayed initiation of transfusion at age 12 years impaired prepubertal growth but they could achieve normal final adult height.

Genotypes and phenotypes of protein S deficiency in Thai children with thromboembolism.

The prevalence of protein S (PS) deficiency in Asian patients with venous thromboembolism is around 8-30%, higher than that in Caucasian populations. The present study reports the genotypes (including one novel mutation) and phenotypes of children with PS deficiency at a tertiary care institute. A total of six patients were included, three with arterial ischemic stroke, two with cerebral venous sinus thrombosis, and one with deep vein thrombosis. PS mutations were identified in four patients: p.R355C, p.G336D, p.E67A, and p.N188KfsX9. p.N188KfsX9 is a novel mutation with less than 20% PS activity noted in heterozygotes.

Combined chelation therapy with daily oral deferiprone and twice-weekly subcutaneous infusion of desferrioxamine in children with ß-thalassemia: 3-year experience.

OBJECTIVE: To study the efficacy of combined treatment with oral and subcutaneous iron chelators. MATERIAL AND METHODS: 50-100 mg/kg/day of oral deferiprone (DFP) combined with 40 mg/kg/dose s.c. desferrioxamine (DFO) twice weekly were given to transfusion-dependent ß-thalassemia children. RESULTS: Enrolled patients (9 with ß-thalassemia major and 33 with ß-thalassemia hemoglobin E), ranging from 3 to 18 years in age, were divided into 3 groups; group 1 ferritin ≥1,000-2,500 ng/ml (n = 10), group 2 ferritin >2,500-4,000 ng/ml (n = 23) and group 3 ferritin >4,000 ng/ml (n = 9). Of the 42 patients, 28 reached the 36-month follow-up. Ten patients whose ferritin declined <15% while receiving 100 mg/kg/day of DFP were considered nonresponders. The median age and previous transfusion duration before enrollment were significantly higher in nonresponders than responders (p = 0.04 and 0.003, respectively). The responders exhibited a significant fall in median ferritin levels from 2,954.6 to 936.6 ng/ml (p < 0.001). Time to a significant decrease in serum ferritin among responders was 6 months. In 13 patients, 16 episodes of adverse events occurred: hemophagocytosis with cytopenia (n = 1), neutropenia (n = 2), thrombocytopenia (n = 2), elevated alanine aminotransferase (n = 5), elevated serum creatinine (n = 1), proteinuria (n = 1) and gastrointestinal discomfort (n = 4). CONCLUSION: Combination therapy with daily oral DFP and subcutaneous DFO twice weekly is a safe and effective alternative to chelation monotherapy in ß-thalassemia children.

Global fibrinolytic activity, PAI-1 level, and 4G/5G polymorphism in Thai children with arterial ischemic stroke.

BACKGROUND: Prolonged euglobulin clot lysis time (ECLT) and increased level of plasminogen activator inhibitor-1 (PAI-1) were reported to be risk factors of arterial ischemic stroke (AIS) by some studies; however, these findings were not supported by other studies. The objective of this study was to determine the association of ECLT, PAI-1 level, and polymorphisms of 4G and 5G of PAI-1 gene to the development of AIS in Thai children. METHODS: This study included patients aged 1-18 years old. Diagnosis of AIS was confirmed by imaging study. The control group was age- and sex-matched healthy subjects. Demographic data were recorded, and blood was tested for ECLT, PAI-1 level, lipid profiles, fasting blood sugar (FBS), and 4G and 5G polymorphisms of PAI-1 gene. RESULTS: There were 70 subjects participating in this study, consisting of 30 patients and 40 controls. Demographic data, lipid profiles, and FBS were similar between the 2 groups. Furthermore, ECLT and PAI-1 level did not differ between patient and control groups; however, both showed significant correlation (r = .352, P = .006). The 4G/5G polymorphism was the most common genotype in both patient and control groups (69.0% vs. 80.0%). However, 4G and 5G polymorphisms of PAI-1 gene did not correlate with PAI-1 level in this study (P = .797). CONCLUSIONS: The PAI-1 level and 4G/5G polymorphism may not be a risk factor of AIS in this population. It was also found that the 4G/5G polymorphism was the most common PAI-1 genotype in this study.

New mathematical formula for differentiating thalassemia trait and iron deficiency anemia in thalassemia prevalent area: a study in healthy school-age children.

Iron deficiency anemia (IDA) and thalassemias are common diseases especially in the Mediterranean, Middle East and Asian regions. Both conditions show the same clinical findings of hypochromic and microcytic red blood cells. Although previous studies have devised mathematical formulae to differentiate between these two conditions, the prevalence of alpha- and beta-thalassemias among the affected populations may undermine the accuracy of these formulae. This study generated a new formula that was able to differentiate IDA and thalassemia traits and to determine the incidence rates of IDA and thalassemia traits. A total of 345 healthy Thai children with a mean age (+/- SD) of 11.3 (+/- 1.7) years were enrolled. Complete blood count, iron status, hemoglobin typing and DNA for alpha-1 thalassemia identification were investigated. Discriminant analysis was used to create a new mathematical formula containing significant variables to differentiate between IDA and thalassemia traits. The new formula of (1.5 Hb-0.05 MCV >14) had a receiver operator characteristic curve of 0.92 in differentiating thalassemia traits from IDA, with sensitivity and specificity of 84.6 and 87.5%, respectively. The incidence of IDA and thalassemia traits in the study group was 12% and 32%, respectively. This formula should be useful as a screening tool to differentiate between these two conditions.

Activation of a cryptic splice site in a potentially lethal coagulation defect accounts for a functional protein variant.

Changes at the invariable donor splice site +1 guanine, relatively frequent in human genetic disease, are predicted to abrogate correct splicing, and thus are classified as null mutations. However, their ability to direct residual expression, which might have pathophysiological implications in several diseases, has been poorly investigated. As a model to address this issue, we studied the IVS6+1G>T mutation found in patients with severe deficiency of the protease triggering coagulation, factor VII (FVII), whose absence is considered lethal. In expression studies, the IVS6+1G>T induced exon 6 skipping and frame-shift, and prevented synthesis of correct FVII transcripts detectable by radioactive/fluorescent labelling or real-time RT-PCR. Intriguingly, the mutation induced the activation of a cryptic donor splice site in exon 6 and production of an in-frame 30bp deleted transcript (8 ± 2%). Expression of this cDNA variant, lacking 10 residues in the activation domain, resulted in secretion of trace amounts (0.2 ± 0.04%) of protein with appreciable specific activity (48 ± 16% of wt-FVII). Altogether these data indicate that the IVS6+1G>T mutation is compatible with the synthesis of functional FVII molecules (~0.01% of normal, 1pM), which could trigger coagulation. The low but detectable thrombin generation (352 ± 55nM) measured in plasma from an IVS6+1G>T homozygote was consistent with a minimal initiation of the enzymatic cascade. In conclusion, we provide experimental clues for traces of FVII expression, which might have reverted an otherwise perinatally lethal genetic condition.

Acquired hypoprothrombinemia inducing bleeding in a girl with transient antiphospholipid antibody: case report.

BACKGROUND: Congenital or acquired prothrombin deficiency is a rare condition. CASE REPORT: A 2-year-7-month old Thai girl presented with ecchymosis, bleeding at both thighs and right ear lobe after a self-limited viral infection. RESULTS: The investigations revealed prolonged APTT and PT, prothrombin level 6% and positive anticardiolipin antibody 26.2 IU/mL. The 1:1 mixture of her plasma and normal plasma could not normalize her APTT and PT. The inhibitor to prothrombin determined by Bethesda method was 0.62 BU. She was responsive to 20 ml/kg of FFP transfusion, followed by 10 ml/kg at an interval of 12 h for three days and daily 500 units of prothrombin complex concentrate administration for three days. At two-week follow-up, she had no bleeding symptom, coagulation tests were normal, prothrombin level was normalized at 94%, no inhibitor to prothrombin was detected, and anticardiolipin antibody became negative. The additional DNA analysis of her prothrombin gene revealed nine different polymorphisms for which seven had been found in patients with congenital prothrombin deficiency and two were novel (4096T-->C, 4097T-->C). These single nucleotide polymorphisms are not the disease-causing mutations. In addition, neither known mutations inducing congenital prothrombin deficiency were identified. CONCLUSION: The acquired hypoprothrombinemia was concluded as the cause of bleeding in this reported patient. It might be caused by the transient low titer of antiphospholipid antibody, which was responsive to replacement therapy of FFP and prothrombin complex concentrate.

The Association Between HLA Class II Alleles and the Occurrence of Factor VIII Inhibitor in Thai Patients with Hemophilia A.

OBJECTIVE: This study aimed to investigate the association between HLA class II alleles and the occurrence of FVIIIinhibitor in Thai hemophilia A patients. MATERIAL AND METHODS: The distribution of HLA-DRB1 alleles and DQB1 alleles in 57 Thai hemophilia A patientsand 36 blood donors as controls was determined using the PCR sequence-specific primer (PCR-SSP) method, and theassociation between the occurrence of factor VIII (FVIII) inhibitor and the presence of certain HLA class II alleles wasinvestigated. RESULTS: The frequency of HLA-DRB1*15 was higher in the hemophilia A patients with and without FVIII inhibitor,whereas that of DRB1*14, DRB1*07, and DQB1*02 was lower in the hemophilia A patients with FVIII inhibitor, ascompared to controls. Interestingly, only the frequency of DRB1*15 was significantly higher in the patients with inhibitorthan in the controls (P = 0.021). Moreover, the frequency of DRB1*15 in the patients with inhibitor was higher than inthose without inhibitor (P = 0.198). CONCLUSION: The study's findings show that the DRB1*15 allele might have contributed to the occurrence of inhibitorin the Thai hemophilia A patients; however, additional research using larger samples and high-resolution DRB1 typingis warranted.

Prominent Mutation of Intron 22 Inversion in Sporadic Hemophilia: Is It Worth the Antenatal Screening?

Background: Adequate replacement for patients with hemophilia is costly, especially in countries with limited resources. Objective: Factor VIII gene mutations among Thai patients with hemophilia A were analyzed for the most common mutation. The cost-effectiveness of finding one female without family history of hemophilia possessing the most common factor VIII mutation was compared with the cost of treating one patient with hemophilia. Methods: In all, 109 unrelated patients with hemophilia A, defined as sporadic cases (n=58) and hereditary cases (n=51), were enrolled for genotypic analysis. Results: Intron 22 inversion was prominently found in 34 sporadic (58.6%) and 27 hereditary (51.9%) cases. The screening for intron 22 inversion among females without family history of hemophilia at antenatal care has been optionally suggested. A female with a positive result will undergo further prenatal diagnosis of hemophilia in her male offspring. On the contrary, a female with a negative test result remains at risk to have a hemophiliac son caused by other factor VIII gene mutations not included in the screening but the risk is not as high as intron 22 inversion. Although the screening of factor VIII mutation among females without family history of hemophilia is against the current practice, it has been initiated due to the inadequate treatment provided to patients with hemophilia in countries with limited resources. The study calculated approximately one female with intron 22 inversion would exist among 17,064 females without family history of hemophilia. The cost of screening (194,870 USD) was much less than that of treating one patient with hemophilia from birth to 40 years of age by the current regimen (378,000 USD). Conclusion: Implementing antenatal screening of intron 22 inversion among females without family history of hemophilia is optionally suggested, especially in economically less-developed countries with inadequate treatment service for patients with hemophilia.

Three-Decade Successive Establishment of Care for Women/Girls from Families with Haemophilia.

Objective: The study aimed to report a 3-decade successive establishment of care for women/girls from families with haemophilia. Methods: A retrospective analysis was conducted on 462 women/girls from 243 families from 1987 to 2021. Results: Combining phenotypic analysis of coagulation factor and genotypic analysis of either linkage analysis or mutation detection confirmed the status of all obligate haemophilia carriers (A118, B19). For potential carrier, 159 proven carriers (A130, B29) and 146 noncarrier status (A126, B20) were diagnosed except 20 potential carriers (A16, B4). Only 54 prenatal diagnoses were requested resulting in normal males (n = 21), males with haemophilia A (n = 12) and females with either normal or carrier status (n = 21). Additionally, 40 women/girls with haemophilia carrier received a diagnosis of severe haemophilia A with Turner's syndrome (n = 2) and mild haemophilia (A31, B7). The skewed X-chromosome inactivation of the nonmutant factor VIII/IX carrying X-chromosome of 8% (2/25) was found in mild haemophilia. Factor concentrate and desmopressin are prescribed for these affected women/girls. The response of women/girls with either haemophilia carrier or haemophilia was amazement with their religious beliefs and cultural acceptance. Conclusion: Appropriate care for women/girls from families with haemophilia concerning diagnosis and management of haemophilia and carrier has been successively established.

Laboratory predictors of dengue shock syndrome during the febrile stage.

The clinical manifestations of dengue hemorrhagic fever (DHF) consist of three successive stages: febrile, toxic and convalescent. The toxic stage is the critical period, which may manifestas circulatory disturbance or even profound shock in some patients. We attempted to determine predictors for the risk of dengue shock syndrome (DSS) during the febrile stage. One hundred one children with acute febrile illness were enrolled in the study, with a mean age of 11 years old. The diagnosis included dengue fever (DF) 21 cases, DHF grade I 30 cases, DHF grade II 33 cases, DHF grades III and IV 10 cases; children with other febrile illnesses (OFI) 7 cases were used as controls. Complete blood counts, coagulation tests, von Willebrand factor antigens (VWF:Ag) and ristocetin cofactor activity (VWF:Rcof) were determined daily during hospitalization and 2-4 weeks after discharge from the hospital. The results revealed any one of the following abnormal laboratory findings during the febrile stage served as a predictor for risk of DSS: increase in hematocrit > 25%, a platelet count < 40,000/microl, an activated partial thromboplastin time >44 seconds, a prothrombin time >14 seconds, a thrombin time >16 seconds or a VWF:Ag or VWF:Rcof > 210%. The relative risk ranged from 4.8 to 10.9. Simple laboratory investigations with complete blood count, coagulation test or the more sophisticated von Willebrand factor, are helpful in predicting the risk for DSS during the febrile stage.

PROC Promoter Single Nucleotide Polymorphisms Associated With Low Protein C Activity But Not Increased Risk of Thromboembolism in Pediatric Population.

Protein C (PC) deficiency, caused by mutations of the PROC gene, is a common inherited risk factor of thromboembolism (TE) among Thai people. This study aimed to investigate the association of 3 single nucleotide polymorphisms (SNPs; -1654 C/T, -1641 A/G, -1461A/T) at the PROC promoter region with PC activity and the risk of developing TE. A total of 216 patient s with TE, diagnosed at aged 0 to 20 years, and 102 healthy adults were enrolled. The SNPs were identified by Sanger sequencing. Protein C activity was measured using an automated functional clotting assay. Linear and logistic regression analyses were used to determine the association of SNPs with PC activity and the risk of TE. Patients and controls with homozygous TAA (119.6% ± 26.1%) and CGT haplotypes (102.7% ± 22.6%) had significantly lower PC activity than those with a homozygous CAA haplotype (140.4% ± 44.9%); P = .027 and .016, respectively. However, none of these haplotypes increased the risk of TE. This study suggested that the 3 PROC promoter SNPs were shown to be associated with lower PC activity but did not increase the risk of TE.

A novel mutation of cystathionine beta-synthase gene in a Thai boy with homocystinuria.

The authors reported a 14-year-old boy who presented with multiple organs thrombosis and subluxation of lens. His diagnosis of homocystinuria was delayed owing to the unrecognition of the disease resulting in significant morbidity. The mutation analysis showed one novel mutation that can explain the high level of plasma homocysteine.

Generation of a human induced pluripotent stem cell line (MUi010-A) from skin fibroblast of patient carrying a c.2104C>T mutation in MYH9 gene.

Mutations in MYH9 gene is one of the major causes of inherited thrombocytopenia resulted from nonfunctional myosin-9 protein. We have generated a human induced pluripotent stem cell line MUi010-A from skin fibroblasts of a patient who had a point mutation c.2104C>T (p.R702C) in the exon 16 of MYH9 gene using a non-integrative reprogramming method. The MUi010-A exhibited embryonic stem cell-like characteristics with consistent pluripotent markers expression, was capable of all three embryonic germ layers differentiation, and had a normal karyotype.