GC-CI-MS-SIM方法诊断新生儿苯丙酮尿症

苯丙酮尿症 (PKU)的发病原因是患者苯丙氨酸羟化酶的缺陷 ,从而导致体内苯丙氨酸 (Phe)不能正常代谢为酪氨酸 (Tyr) ,前者在体内大量堆积并氧化为有害的苯丙酮酸 .PKU是目前筛查范围最广的氨基酸代谢遗传疾病 ,全世界每年约有一千万婴儿接受 PKU筛查 ;在中国 PKU也是卫生部要求重点筛查的病种1] .目前常规筛查方法是细菌抑制法 (BIA) ,它的特点是费用低、速度慢、容易产生假阳性 ;Chace等 2 ,3] 报道了 MS- MS方法筛查新生儿 PKU.曲峻等 4 ] 发展了 Chace的方法 ,采用 HPLC与MS- MS联用方法 (LC- MS- MS)筛查新生儿 PK…

Newborn Screening of Phenylketonuria by GC-CI-MS-SIM

The application of MS in newborn screening is one of the most important branches of MS′s current clinical application.In this paper we first reported a new method of newborn screening for Phenylketonuria (PKU) by GC-CI-MS-SIM,which was relatively cheap,fast,sensitive and accurate.In this method Phenylalanine (Phe) and Tyrosine (Tyr) were extracted from dry blood spots with 0.1％ mol/L HCl-methanol.The protein in the extraction was gotten rid of by centrifugor.Phe and Tyr were reacted with 3.0 mol/L HCl-butanol,then the products Phe and Tyr butyl esters were reacted with trifluoroacetic anhydride.The final derivations from Phe and Tyr,alanine,3-phenyl-N(trifluoroacetyl)-,butyl este and L-tyrosine,N(trifluoroacetyl)-,butyl ester,trifl were analyzed by GCCI-MS-SIM.The contents of the two amino acids in blood samples were determined by calculating the areas of their final derivations with exterior standard.Finally,the molar ratios of Phe to Tyr in blood sample were calculated as the basis of PKU diagnosis.Because chemical ionization and selective ion measurement were used in this method,the limits of detection for Phe and Tyr were low and the sensitivity was excellent.About 30 blood samples were analyzed by this method,and the results prove that this method could successfully discriminate between normal infants and PKU positive ones.The price of instrument GC-MS is cheaper than that of MS-MS.Therefore it was capable for large-scale screening in developing countries.