Biomedical subjects

Kaoru Nishiyama

Publications and source records attributed to Kaoru Nishiyama.

6 recordsLinked to original sources

PubMed2004

C677T mutation in the MTHFR gene was not found in patients with frontoethmoidal encephalocele in East Java, Indonesia.

BACKGROUND: Frontoethmoidal encephalocele (FEE) is a neural tube defect (NTD) characterized by a congenital bone defect in the anterior cranium and herniation of the intracranial mass through the defect. The C677T mutation in the 5,10-methylenetetrahydrofolate reductase gene (MTHFR) has been reported as a genetic risk factor for spina bifida. However, the role of the MTHFR in the pathogenesis of FEE remains to be clarified. METHODS: A hospital-based survey of FEE patients who were referred to the Department of Neurosurgery and Plastic Surgery, Malang General Hospital, East Java, Indonesia was conducted. Genetic screening of MTHFR substitutions in 13 patients and eight mothers from 11 affected families were performed using a combination of polymerase chain reaction (PCR), denaturing high-performance liquid chromatography (DHPLC), and direct sequencing. RESULTS: In total, 130 patients with FEE among 138 NTD patients (94.2%) were identified. The ratios of cranial encephalomeningocele to spinal meningocele (32 : 1) and of FEE to occipital encephalomeningocele (32 : 1) were higher than those in other populations. Five substitutions were detected in the MTHFR: C121T, C677T, C1060T, A1298C, and G1793A. No significant differences were found in the frequency of each nucleotide substitution between patients or mothers and controls. In addition, none of the subjects in this study were homozygous for T at nucleotide position 677. CONCLUSION: FEE is the most common form of NTD in East Java, Indonesia. Genetic analysis of 11 affected families suggests that the MTHFR gene is not associated with the development of FEE, although the number of FEE families analyzed in this study was very limited.

Adult↗

PubMed2003

High prevalence of Southeast Asian ovalocytosis in Malays with distal renal tubular acidosis.

Southeast Asian ovalocytosis (SAO) is a red blood cell abnormality common in malaria-endemic regions and caused by a 27 nt deletion of the band 3 protein gene. Since band 3 protein, also known as anion exchanger 1, is expressed in renal distal tubules, the incidence of SAO was examined in distal renal tubular acidosis (dRTA) in Malays in Kelantan, Malaysia. Twenty-two patients with dRTA and 50 healthy volunteers were examined for complication of SAO by both morphological and genetic analyses. SAO was identified in 18 of the 22 dRTA patients (81.8%), but only two of the 50 controls (4%). The incidence of SAO was significantly high in those with dRTA (p<0.001), indicating a dysfunctional role for band 3 protein/anion exchanger 1 in the development of dRTA.

Acidosis, Renal Tubular↗

PubMed2003

Screening for glucose-6-phosphate dehydrogenase deficiency using a modified formazan method: a pilot study on Filipino male newborns.

BACKGROUND: Glucose-6-phosphate dehydrogenase (G6PD) deficiency has increased prevalence rates in tropical Africa, tropical and subtropical Asia and some parts of the Mediterranean. Earlier studies on G6PD deficiency in the Philippines have shown prevalence rates of 4.5% to 25.7%. METHODS: In the present study, 3278 male newborns were screened for G6PD deficiency using the modified formazan method, a simple screening procedure affordable in the setting of a developing country. Subjects with positive screening results were recalled for confirmatory testing using a commercial assay kit for quantitative enzyme determination. RESULTS: Of the 3278 boys studied, 186 revealed positive screening results. Of the 186, 65 boys had confirmatory testing. Of these 65 boys, 45 were confirmed to have G6PD deficiency and 20 had normal results. This study reveals an incidence of G6PD deficiency of 3.9% among male Filipinos. CONCLUSIONS: This study recommends the inclusion of G6PD deficiency in the panel of disorders for newborn screening among Filipino newborns.

Formazans↗

PubMed2003

Glucose-6-phosphate dehydrogenase deficiency: molecular heterogeneity in southeast Asian countries.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is common in malaria endemic regions and is estimated to affect more than 400 million people worldwide. Deficient subjects are mostly asymptomatic but clinical manifestations range from neonatal jaundice due to acute hemolytic anemia to chronic non-spherocytic hemolytic anemia. To date, biochemical parameters allowed more than 400 different G6PD variants to be distinguished thereby suggesting a vast genetic heterogeneity. So far, only a small portion of this heterogeneity has been confirmed at the DNA level with the identification of about 90 different point mutations in the G6PD coding sequence. To determine the molecular background of G6PD deficiency in Southeast Asian countries, we conducted molecular analyses of G6PD patients from the Philippines, Malaysia, Singapore, Vietnam and Indonesia. The most prevalent mutation identified differs from country to country, thus suggesting independent mutational events of the G6PD gene.

Asia, Southeastern↗

PubMed2002

Molecular heterogeneity of glucose-6-phosphate dehydrogenase deficiency in Malays in Malaysia.

Multiplex polymerase chain reaction (PCR) using multiple tandem forward primers and a common reverse primer (MPTP) was recently established as a comprehensive screening method for mutations in X-linked recessive diseases. In the work reported here, MPTP was used to scan for mutations of the glucose-6-phosphate dehydrogenase (G6PD) gene. Mutations in exons 3,4,5,6,7,9, 11, and 12 of the G6PD gene were screened by MPTP in 93 unrelated Malaysian patients with G6PD deficiency. Of the 93 patients, 80 (86%) had identified mutations. Although all of these were missense mutations, identified nucleotide changes were heterogeneous, with 9 mutations involving various parts of the exons. These 9 mutations were G-to-A nucleotide changes at nucleotide 871 of the G6PD gene (G871A), corresponding to G6PD Viangchan, G6PD Mediterranean (C563T), G6PD Vanua Lava (T383C), G6PD Coimbra (C592T), G6PD Kaiping (G1388A), G6PD Orissa (C131G), G6PD Mahidol (G487A), G6PD Canton (G1376T), and G6PD Chatham (G1003A). Our results document heterogeneous mutations of the G6PD gene in the Malaysian population.

DNA Mutational Analysis↗

PubMedDate not supplied

Molecular heterogeneity of glucose-6-phosphate dehydrogenase (G6PD) variants in the south of Thailand and identification of a novel variant (G6PD Songklanagarind).

Two hundred and twenty-five G6PD-deficient subjects in Songklanagarind Hospital in the south of Thailand comprising 210 males and 15 females were studied. Neonatal jaundice was detected in 85% of these patients. Acute hemolysis related to infection was detected in 17.3% of the G6PD-deficient subjects. Drug-induced acute hemolysis was detected in 1.8% and favism was observed in 3.6% of G6PD-deficient patients. The molecular analysis was performed on 134 G6PD-deficient individuals by a combination of PCR-RFLP, multiplex polymerase chain reaction by multiple tandem forward primers and a common reverse primer assay (MPTP) and DNA sequencing to characterize the mutations of the samples with abnormal MPTP bands. We found 10 different missense G6PD mutations and the three most common variants were G6PD Viangchan 871,G-->A (31.3%), G6PD Kaiping 1388,G-->A (20.1%) and G6PD Mahidol 487,G-->A (17.2%) followed by G6PD Canton 1376,G-->T (9.7%), G6PD Union 1360,C-->T (2.2%), G6PD Gaohe 95,A-->G (1.5%), G6PD Quing Yuan 392,G-->T (0.7%), G6PD Mediterranean 563,C-->T (0.7%), G6PD Songklanagarind 196,T-->A (0.7%), silent mutation 1311,C-->T (6.7%), and uncharacterized variant (9%). A novel missense mutation at codon 196, TTC-->ATC in exon 4 of the G6PD gene predicting a single amino acid substitution, Phe66Ile was identified and we designated this novel class II variant as G6PD Songklanagarind. The G6PD variants among the Thais in the southern part are heterogeneous and G6PD Viangchan, Kaiping, Mahidol, and Canton variants account for about 78% of the cases. Our findings provide some evidence that G6PD Viangchan and Mahidol are common Southeast Asian variants and support the theory of genetic drifts throughout Southeast Asia.

Female↗