[Analysis of newborn screening for galactosemia and genotype-phenotype of confirmed galatosemia cases].

Objective: To investigate the prevalence of galactosemia(GAL), and the characteristics of genotype and phenotype of newborns who were confirmed with GAL in newborn screening in Zhejiang province. Method: The number of all live births, newborn screened infants and all clinical data of confirmed newborns with GAL from October 2013 to March 2015 were retrospectively analyzed by reviewing the data of Zhejiang Province screening center database. And the characteristics of genes and the clinical data of GAL cases who were confirmed by correlative gene test and enzyme activity measurement were analyzed. Result: The prevalence of GAL in Zhejiang province was 1/189 857. Among them, there was 1 case confirmed with GAL typeⅠ (prevalence, 1/759 428), with mutations of c. 904+ 1G>T and c. 687G>A, the enzyme activity of galactose-1-phosphate uridyltransferase (GALT) was 56.4% of controls. And there was 1 case of GAL typeⅡ(prevalence, 1/759 428), with mutations of c. 85G>T and c. 502G>A. There were 2 cases confirmed with GAL type Ⅲ(prevalence, 1/379 714), with mutations of c. 505C>T, c. 452G>A, c. 280G>A and c. 925G>A, the enzyme activity of UDP-galactose-4'-epimerase (GALE) were 42% and 38% of controls, respectively. All cases had different abnormal biochemical marks of liver function, and 1 case had combined hyperlactacidemia or hyperammonemia or increase of multiple kinds of amino acids, respectively. The newborn of GAL type Ⅱ had phacoscotasmus before treatment. All the cases were fed with lactose free milk powder, and all the abnormal parameters were improved during following up. Conclusion: The disease of GAL is rare in Zhejiang province, and its genotype distribution is scattered with comparatively mind clinical manifestations, and the cases with early treatment with lactose free milk powder have good prognosis. All cases needed to be treated and followed up for a life-long time. It is recommended that the high risk cases with GAL should be screened as soon as possible.目的： 探讨新生儿半乳糖血症(GAL)患病率、GAL基因谱分布及其临床表型。 方法： 利用浙江省筛查中心数据库，统计2013年10月—2015年3月GAL筛查期间所有活产婴儿、新生儿筛查人数，回顾性研究经基因/酶活性检测确诊的GAL病例所有临床资料，分析基因分布及临床特点。 结果： GAL患病率1/189 857。其中GALⅠ型1例(患病率1/759 428)，基因型为c.904＋1G>T、c.687G>A，GALT酶活性为正常对照的56.4%；GALⅡ型1例(患病率1/759 428)，基因型为c.85G>T、c.502G>A；GALⅢ型2例(患病率1/379 714)，基因型分别为：c.505C>T、c.452G>A及c.280G>A、c.925G>A，GALE酶活性分别为正常对照的42%、38%。所有病例均有不同程度肝功能改变；其中合并高乳酸、高血氨、多种氨基酸增高各1例；GALⅡ型患儿治疗前出现晶状体混浊。所有患儿均需无乳糖奶粉喂养，随访中异常指标均改善，生长发育正常。 结论： GAL在浙江省罕见；其基因型分布分散；临床表现多为轻症型。早期治疗预后良好，需终身随访。建议临床高危病例早期行GAL筛查。.