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ID 83489
著者
Chen, Shuli Department of Pediatrics, The University of Tokushima School of Medicine
イトウ, ミチノリ Department of Pediatrics, The University of Tokushima School of Medicine
サイジョウ, タカヒコ Department of Pediatrics, The University of Tokushima School of Medicine
ナイトウ, エツオ Department of Pediatrics, The University of Tokushima School of Medicine
黒田, 泰弘 Department of Pediatrics, The University of Tokushima School of Medicine 徳島大学 教育研究者総覧
キーワード
cystathionineβ-Synthase Deficiency
homocystinuria
mutation analysis
neonatal mass screening
資料タイプ
学術雑誌論文
抄録
Two mutations in the cystathionine β-synthase (CBS) gene were found in two Japanese siblings with pyridoxine non-responsive homocystinuria who had different methionine levels in their blood during the neonatal period. Both patients were com-pound heterozygotes of two mutant alleles:one had an A-to-G transition at nucleotide194 (A194G) that caused a histidine-to-arginine substitution at position 65 of the protein (H65R), while the other had a G-to-A transition at nucleotide346 (G346A) which resulted in a glycine-to-arginine substitution at position 116 of the protein (G116R). The two mutant proteins were separately expressed in Escherichia coli, and they completely lacked catalytic activity.
Despite their identical genotypes and almost equal protein intake, these siblings showed different levels of blood methionine during the neonatal period, suggesting that the level of methionine in blood is determined not only by the defect in the CBS gene and protein intake, but also by the activity of other enzymes involved in methionine and homocysteine metabolism, especially during the neonatal period. Therefore, high-risk newborns who have siblings with homocystinuria, even if the level of methionine in their blood is normal in a neonatal mass screening, should be followed up and diagnosed by an assay of enzyme activity or a gene analysis so that treatment can be begun as soon as possible to prevent the development of clinical symptoms. In addition, a new, more sensi-tive method for the mass screening of CBS deficiency in neonates should be developed.
掲載誌名
The journal of medical investigation : JMI
ISSN
13431420
cat書誌ID
AA11166929
46
3-4
開始ページ
186
終了ページ
191
並び順
186
発行日
1999
備考
フルテキストファイル
言語
eng
部局
医学系