California Department of Public Health, Genetic Disease Laboratory Branch, Genetic Disease Screening Program, 850 Marina Bay Parkway, Richmond, CA 94804, USA.
California Department of Public Health, Genetic Disease Laboratory Branch, Genetic Disease Screening Program, 850 Marina Bay Parkway, Richmond, CA 94804, USA.
Clin Chim Acta. 2014 Sep 25;436:298-302. doi: 10.1016/j.cca.2014.06.011. Epub 2014 Jun 25.
The California newborn screening program uses newborns' dried blood spots (DBS) to screen for more than 45 genetic disorders. Deficiency of galactose-1-phosphate uridyl transferase (GALT) is one of the metabolic genetic disorders screened using newborn DBS. During follow-up tests, common mutations of the GALT gene have been identified using whole blood samples. To avoid the stress of drawing an additional blood sample from newborns who are identified as presumptive positive for galactosemia, we developed a method to test common mutations in the GALT gene using blood spots.
This method involves DNA extraction from DBS, followed by polymerase chain reaction (PCR), and single nucleotide extension (SNE). SNE products were detected by capillary electrophoresis.
In a double-blind study, GALT gene common mutations/variants: IVS2-2A>G, p.S135L, p.T138M, p.Q188R, p.L195P, p.Y209C, p.L218L, p.K285N, and p.N314D were detected in seventy-three DBS which had previously been screened and confirmed as positive in the California Newborn Screening Program. Mutations found using blood spots gave 100% concordance with mutations from previously genotyped whole blood samples.
This blood spot method decreases the genomic test turnaround time of GALT screened positive patients and potentially reduces emotional stress on families required to provide an additional blood draw.
加利福尼亚州新生儿筛查计划使用新生儿干血斑（DBS）筛查超过 45 种遗传疾病。半乳糖-1-磷酸尿苷转移酶（GALT）缺乏症是使用新生儿 DBS 筛查的代谢遗传疾病之一。在随访测试中，已经使用全血样本鉴定了 GALT 基因的常见突变。为了避免对被鉴定为疑似半乳糖血症的新生儿额外抽取血液样本的压力，我们开发了一种使用血斑测试 GALT 基因常见突变的方法。
该方法涉及从 DBS 中提取 DNA，然后进行聚合酶链反应（PCR）和单核苷酸延伸（SNE）。通过毛细管电泳检测 SNE 产物。
在一项双盲研究中，加利福尼亚州新生儿筛查计划先前筛查并确认阳性的 73 个 DBS 中检测到 GALT 基因常见突变/变体：IVS2-2A>G、p.S135L、p.T138M、p.Q188R、p.L195P、p.Y209C、p.L218L、p.K285N 和 p.N314D。使用血斑发现的突变与先前基因分型的全血样本中的突变完全一致。
这种血斑方法缩短了 GALT 筛查阳性患者的基因组测试周转时间，并可能减轻家庭提供额外血液样本的情绪压力。
