Campagnoli Monica, Rosipal Stefan, Debreová Marianna, Rosipal Rastislav, Sala Alberto, Romano Assunta, Labò Sara, Galliano Monica, Minchiotti Lorenzo
Department of Biochemistry "A.Castellan", University of Pavia, viale Taramelli 3B, 27100 Pavia, Italy.
Clin Chim Acta. 2006 Mar;365(1-2):188-93. doi: 10.1016/j.cca.2005.08.016. Epub 2005 Sep 22.
Analbuminemia is a rare autosomal recessive disorder manifested by the absence, or severe reduction, of circulating serum albumin. Here we report three new cases of hereditary analbuminemia, fortuitously detected in three Slovak Romany children, members of the same family, and define the molecular defect that causes the analbuminemic trait.
Total DNA, extracted from peripheral blood samples from six members of the family, was PCR-amplified using oligonucleotide primers designed to amplify the 14 exons of the human albumin gene and the flanking intron regions. The products were screened for mutations by single-strand conformation polymorphism (SSCP) and heteroduplex analyses (HA). HA allowed the identification of the abnormal fragment, which was then sequenced.
In the 3 patients the analbuminemic trait was caused by the same mutation, an AT deletion at nucleotides 2430-31, the 91 th and 92 th bases of exon 3. This defect, previously identified as Kayseri mutation, produces a frameshift leading to a premature stop, two codons downstream. The predicted translation product would consist of 54 amino acid residues. The parents were found to be heterozygous for the mutation.
Our results confirm that the combination of SSCP and HA represents a powerful tool to study the molecular defects causing analbuminemia in humans.
无白蛋白血症是一种罕见的常染色体隐性疾病,表现为循环血清白蛋白缺失或严重减少。在此,我们报告在同一家族的三名斯洛伐克罗姆儿童中偶然发现的三例遗传性无白蛋白血症新病例,并确定导致无白蛋白血症性状的分子缺陷。
从该家族六名成员的外周血样本中提取的总DNA,使用设计用于扩增人白蛋白基因的14个外显子及其侧翼内含子区域的寡核苷酸引物进行PCR扩增。通过单链构象多态性(SSCP)和异源双链分析(HA)筛选产物中的突变。HA可鉴定异常片段,然后对其进行测序。
在这3名患者中,无白蛋白血症性状由相同突变引起,即第3外显子第91和92位碱基处2430 - 31位核苷酸的AT缺失。此缺陷先前被鉴定为开塞利突变,会产生移码,导致在下游两个密码子处提前终止。预测的翻译产物将由54个氨基酸残基组成。发现父母为该突变的杂合子。
我们的结果证实,SSCP和HA的组合是研究导致人类无白蛋白血症的分子缺陷的有力工具。