Three Japanese families with Van der Woude syndrome (VWS) were screened for mutations in the interferon regulatory factor 6 gene (IRF6) by sequencing its entire coding region. Two novel missense ...mutations, R45Q in exon 3 and P396S in exon 9, were identified in families 1 and 2, respectively. In family 3, no causative base change was found by the sequencing analysis, but a deletion involving exons 4-9 was suggested by multiplex PCR analysis. To confirm the deletion and to determine its 5'- and 3'-boundaries, we amplified a DNA fragment containing a heterozygous polymorphic site in exon 2 by using a 5'-upstream forward PCR primer and eight different reverse primers located 3'-downstream of exon 2. The amplified product was subjected to nested PCR to generate a DNA fragment containing the polymorphic site. When a reverse primer located within the deletion was used for the first PCR amplification, only the nondeletion allele was detected after the second PCR. Repeated analyses with eight different reverse primers allowed us to map the boundaries of the deletion, and subsequently a heterozygous 17,162-bp deletion involving exons 4-9 was identified. Since IRF6 mutations in a significant portion of VWS patients remain undetected by conventional sequencing analysis, it may be important to search for a large deletion in those patients. Our simple methods to identify deletions and to determine the boundaries of a deletion would facilitate the identification of such patients.
Glycine encephalopathy (GE) (non-ketotic hyperglycinemia) is an autosomal recessive neurometabolic disease caused by defective activity of the glycine cleavage system. Clinically, patients present ...usually in the neonatal period with hypotonia, encephalopathy, hiccups and breath arrests with or without overt seizures. GE is considered rare, but its incidence is relatively high in several geographical areas around the world. We report a novel mutation causing GE in six extended Arab families, all from a small suburban village (population 5,000). A methionine to threonine change in the initiation codon of the glycine decarboxylase gene led to markedly reduced glycine decarboxylase mRNA levels and abolished glycine cleavage system activity.
Objectives/Hypothesis: Recent developments in molecular genetics have opened a new era in genetic analysis accompanied by new concepts concerning genetic disorders. Although 30 genes responsible for ...nonsyndromic deafness have been discovered as of March 27, 2003, the connexin 26 gene (GJB2) is commonly found in cases of deafness of unknown origins. The GJB2 contains a predicted open reading frame of 785 base pairs, which makes it relatively easy to detect mutations. Accordingly, mutation analysis of GJB2 should be suitable for the screening of congenital deafness.
Study Design: Prospective study.
Methods: IsoCode Stix is a useful device to isolate DNA from small samples of blood, which can be delivered from remote areas. To apply the detection of common mutations of GJB2 to hearing screening, DNA was extracted from several droplets of blood applied to the IsoCode device, and an allele‐specific amplification method with real‐time quantitative polymerase chain reaction was performed using GeneAmp 7700 with SYBR Green I dye.
Results: DNA extracted from IsoCode was purified within 45 minutes, which was sufficient to detect the full sequence of GJB2. Four types of common GJB2 mutations were reliably detected within 2.5 hours.
Conclusion: IsoCode and real‐time quantitative polymerase chain reaction will be promising tools for newborn screening of deafness genes in the future in DNA‐based deafness screening, allowing early diagnosis of deafness and prompt training for language development.
A NbTi split magnet directly cooled by a cryocooler Masuyama, S.; Yamamoto, H.; Matsubara, Y.
IEEE transactions on applied superconductivity,
03/1993, Letnik:
3, Številka:
1
Journal Article, Conference Proceeding
Recenzirano
A novel system consisting of a NbTi coil directly cooled by a G-M cryocooler was successfully constructed. The quench was simulated, focusing on the role of the copper bobbin as the secondary coil. ...Under the optimum conditions, a maximum field of 6.3 T was achieved. It was demonstrated that the critical current can be attained in the temperature range 6 approximately 9 K. After a quench the increment of the coil temperature was less than 50 K and safe operation of the system was demonstrated. The results indicate good possibilities for realization of a split magnet which produces a very high field.< >
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