Kluijtmans L A, Blom H J, Boers G H, van Oost B A, Trijbels F J, van den Heuvel L P
Department of Paediatrics, University Hospital Nijmegen, The Netherlands.
Hum Genet. 1995 Aug;96(2):249-50. doi: 10.1007/BF00207394.
Direct sequencing of the coding region of the cystathionine beta-synthase (CBS) gene in two homocystinuric patients revealed the presence of two novel missense mutations. The first mutation, a 1111G-->A transition, resulted in the substitution of the evolutionary conserved valine-371 by a methionine residue (V371M) and created a new NlaIII restriction site. The second mutation, a G-->A transition at base-pair 494, resulted in an amino acid change from cysteine to tyrosine (C165Y) and abolished a BsoFI restriction site. Both mutations were found in a compound heterozygous state with the previously described 833T-->C transition.
对两名同型胱氨酸尿症患者的胱硫醚β-合酶（CBS）基因编码区进行直接测序，发现存在两个新的错义突变。第一个突变是1111G→A转换，导致进化保守的缬氨酸-371被甲硫氨酸残基取代（V371M），并产生了一个新的NlaIII限制性酶切位点。第二个突变是494位碱基对处的G→A转换，导致氨基酸从半胱氨酸变为酪氨酸（C165Y），并消除了一个BsoFI限制性酶切位点。这两个突变均以复合杂合状态与先前描述的833T→C转换同时存在。
