Search tips
Search criteria

Results 1-4 (4)

Clipboard (0)

Select a Filter Below

Year of Publication
Document Types
1.  Screening of SLC25A13 mutation in the Thai population 
AIM: To determine the prevalence of SLC25A13 mutations in the Thai population.
METHODS: A total of 1537 subjects representing the Thai population were screened for a novel pathologic allele p.Met1? (c.2T > C) and six previously known common SLC25A13 mutations: [I] (c.851_854delGTAT), [II] (g.IVS11 + 1G > A), [III] (c.1638_1660dup), [IV] (p.S225X), [V] (IVS13 + 1G > A), and [XIX] (g.IVS16ins3kb) using a newly developed TaqMan and established HybProbe assay, respectively. Sanger sequencing was employed for specimens showing an aberrant peak to confirm the targeted mutation as well as the unknown aberrant peaks detected. Frequencies of the mutations identified were compared in each region. Carrier frequency and disease prevalence of citrin deficiency caused by SCL25A13 mutations were estimated.
RESULTS: p.Met1? was identified in the heterozygous state in 85 individuals, giving a carrier frequency of 1/18, which suggests possible selective advantage of this variant. The question of p.Met1? homozygote lethality remains unanswered which may serve as an explanation as to why this homozygote has yet to be identified in patients/controls even with high allele frequency. The p.Met1? mutation has rarely been studied in populations other than Thai and Chinese; therefore, may have been overlooked. Development of the TaqMan assay in the present study would allow a simple, rapid, and cost-effective method for mass screening. Heterozygous mutations: [XIX] and [I] were identified in 17 individuals, giving a carrier rate of 1/90 and a calculated homozygote rate of 1/33000. Two novel variants, g.IVS11 + 17C > G and c.1311C > T, of unknown clinical significance were identified at low frequency.
CONCLUSION: This study highlighted the current underestimation of citrin deficiency and suggests the possible selective advantage of the p.Met1? allele.
PMCID: PMC3837273  PMID: 24282362
Aspartate-glutamate carrier; Isoform 2; Citrin deficiency; Type II citrullinemia; Neonatal intrahepatic cholestasis caused by citrin deficiency; SLC25A13
2.  Neonatal intrahepatic cholestasis caused by citrin deficiency: prevalence and SLC25A13 mutations among thai infants 
BMC Gastroenterology  2012;12:141.
The most common causes of cholestatic jaundice are biliary atresia and idiopathic neonatal hepatitis (INH). Specific disorders underlying INH, such as various infectious and metabolic causes, including neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) especially, in East Asian populations are increasingly being identified. Since most NICCD infants recovered from liver disease by 1 year of age, they often are misdiagnosed with INH, leading to difficulty in determining the true prevalence of NICCD. Mutation(s) of human SLC25A13 gene encoding a mitochondrial aspartate/glutamate carrier isoform 2 (AGC2), can lead to AGC2 deficiency, resulting in NICCD and an adult-onset fatal disease namely citrullinemia type II (CTLN2). To study the prevalence of NICCD and SLC25A13 mutations in Thai infants, and to compare manifestations of NICCD and non-NICCD, infants with idiopathic cholestatic jaundice or INH were enrolled. Clinical and biochemical data were reviewed. Urine organic acid and plasma amino acids profiles were analyzed. PCR-sequencing of all 18 exons of SLC25A13 and gap PCR for the mutations IVS16ins3kb and Ex16+74_IVS17-32del516 were performed. mRNA were analyzed in selected cases with possible splicing error.
Five out of 39 (12.8%) unrelated infants enrolled in the study were found to have NICCD, of which three had homozygous 851del4 (GTATdel) and two compound heterozygous 851del4/IVS16ins3kb and 851del4/1638ins23, respectively. Two missense mutations (p.M1? and p.R605Q) of unknown functional significance were identified. At the initial presentation, NICCD patients had higher levels of alkaline phosphatase (ALP) and alpha-fetoprotein (AFP) and lower level of alanine aminotransferase (ALT) than those in non-NICCD patients (p< 0.05). NICCD patients showed higher citrulline level and threonine/serine ratio than non-NICCD infants (p< 0.05). Fatty liver was found in 2 NICCD patients. Jaundice resolved in all NICCD and in 87.5% of non-NICCD infants at the median age of 9.5 and 4.0 months, respectively.
NICCD should be considered in infants with idiopathic cholestasis. The preliminary estimated prevalence of NICCD was calculated to be 1/48,228 with carrier rate of 1/110 among Thai infants. However, this number may be underestimated and required further analysis with mutation screening in larger control population to establish the true prevalence of NICCD and AGC2 deficiency.
PMCID: PMC3483206  PMID: 23067347
AGC2 deficiency; Cholestatic jaundice; Idiopathic neonatal hepatitis; Infantile cholestasis; NICCD; Prevalence
3.  Haplotypes of IL12B promoter polymorphisms condition susceptibility to severe malaria and functional changes in cytokine levels in Thai adults 
Immunogenetics  2010;62(6):345-356.
Polymorphic variability in immune response genes, such as IL12B, encoding the IL-12p40 subunit is associated with susceptibility to severe malaria in African populations. Since the role of genetic variation in conditioning severe malaria in Thai adults is largely unexplored, the functional association between IL12B polymorphisms [i.e., IL12Bpro (rs17860508), and IL12B 3’ UTR T/G (rs3212227)], severe malaria, and cytokine production was examined in patients with Plasmodium falciparum infections (n=355) recruited from malaria endemic areas along the Thai-Myanmar border in northwest Thailand. Circulating IL-12p40 (p=0.049) and IFN-γ (p=0.051) were elevated in patients with severe malaria, while only IL-12p40 was significantly higher in severe malaria patients with hyperparasitaemia (p=0.046). Carriage of the IL12Bpro1.1 genotype was associated with enhanced severity of malaria (OR, 2.34; 95% CI, 0.94–5.81; p=0.066) and hyperparasitaemia (OR, 3.42; 95% CI, 1.17–9.87; p=0.025) relative to the IL12Bpro2.2 genotype (wild type). Individuals with the IL12Bpro1.1 genotype also had the lowest IL-12p40 (p=0.002) and the highest IFN-γ (p=0.004) levels. Construction of haplotypes revealed that carriage of the IL12Bpro-2/3’ UTR-T haplotype was associated with protection against severe malaria (OR, 0.51; 95% CI, 0.29–0.90; p=0.020) and reduced circulating IFN-γ (p=0.06). Thus, genotypic and haplotypic variation at IL12Bpro and IL12B 3’ UTR in this population influences susceptibility to severe malaria and functional changes in circulating IL-12p40 and IFN-γ levels. Results presented here suggest that protection against severe malaria in Thai adults is associated with genotypic variants that condition enhanced IL-12p40 and reduced IFN-γ levels.
PMCID: PMC3057425  PMID: 20387064
IL12B; P. falciparum; severe malaria; single nucleotide polymorphism; haplotype
4.  Carnitine levels and cardiac functions in children with solid malignancies receiving doxorubicin therapy 
Previous studies demonstrated l-carnitine decreasing doxorubicin-induced cardiotoxicity. Our objectives were to study carnitine levels and cardiac functions in children treated with doxorubicin and the effect of short-term l-carnitine supplements.
Materials and Methods:
Serial carnitine levels and cardiac functions were obtained in children with newly diagnosed solid malignancies before doxorubicin, after cumulative doses of ≥150 mg/m2 and ≥300 mg/m2, respectively. Oral l-carnitine 100 mg/kg/day for 3 days were given to the children treated with doxorubicin at cumulative doses of ≥150 mg/m2 and ≥300 mg/m2. Carnitine levels and cardiac functions were also obtained in those children before and after short-term oral l-carnitine at each cumulative dose of doxorubicin.
Five children (3 females), median age of 9.1 years (range 1.5–13 years) with newly diagnosed solid malignancies were enrolled in the study. Free carnitine (FC) tended to decrease while acyl-carnitine (AC) increased making AC/FC ratio increased after cumulative dose of ≥150 and ≥300 mg/m2 but the statistics was not significant. Left ventricular (LV) systolic function was not significantly changed. Interestingly, LV global function (LV myocardial performance index) was significantly increased after 150 mg/m2 (median 0.39, 0.27–0.51) and 300 mg/2 (median 0.46, 0.27–0.50) when compared to baseline (median 0.28, 0.14–0.48) (P=0.05). Carnitine levels and cardiac functions were not significantly changed after oral l-carnitine supplement at cumulative dose of ≥150 mg/m2 (n=6) and ≥300 mg/m2 (n=9).
Carnitine levels tended to decrease after doxorubicin treatment. LV global dysfunction was documented early after doxorubicin. However, short-term l-carnitine supplement did not improve cardiac function.
PMCID: PMC3124989  PMID: 21731215
Anthracycline; cardiac function; cardiac toxicity; children

Results 1-4 (4)