■在这里,我们报告了两个不相关家族中的两个罕见的α-珠蛋白链变体:HbValdeMarne[α133(H16)Ser>Arg(AGC>CGC);HBA2:c.400A>C]和Hb东莞[α52(HBE6)Ser>Cys(TCT>TGT);c.158C>G]。值得注意的是,HBA2:c.400A>C是α2基因第三个外显子中一个未报道的新变异体,首次提出了简单杂合的不稳定Hb东莞血液学特征。
■通过使用毛细管电泳(CE)进行Hb分析。使用悬浮阵列系统检测到23个常见突变。通过DNA测序鉴定突变。
■CE结果显示,在家族1的两个成员中,在区域8处出现一个异常峰,与HbA分离不完全。DNA测序证实存在HbValdeMarne[α133(H16)Ser>Arg(AGC>CGC);HBA2:c.400A>C]。家族2的五个成员在11区表现出异常峰,DNA测序证实了Hb东莞的存在[α52(E6)Ser>Cys(TCT>TGT);HBA1:c.158C>G]。
■HBA2:C.400A>C的发现扩展了α-珠蛋白变体的现有谱。单纯杂合型Hb东莞携带者一般无明显临床症状。这项研究中的信息将帮助临床医生了解筛查,Hb变异的分子诊断及临床意义。
UNASSIGNED: Here we report two rare α-globin chain variants in two unrelated families: Hb Val de Marne [α133(H16) Ser > Arg (AGC > CGC); HBA2: c.400A > C] and Hb Dongguan [α52(E6) Ser > Cys (TCT > TGT); HBA1: c.158C > G]. Notably, HBA2: c.400A > C is an unreported new variant in the third exon of the α2 gene, and simple heterozygous unstable Hb Dongguan haematological characteristics are proposed for the first time.
UNASSIGNED: Hb analysis was performed by using capillary electrophoresis (CE). Twenty-three common mutations were detected using a suspension array system. Mutations were identified by DNA sequencing.
UNASSIGNED: The CE results showed an abnormal peak with incomplete separation from Hb A at zone 8 in two members of Family 1. DNA sequencing confirmed the presence of Hb Val de Marne [α133(H16) Ser > Arg (AGC > CGC); HBA2: c.400A > C]. Five members of Family 2 exhibited an abnormal peak at zone 11, and DNA sequencing confirmed the presence of Hb Dongguan [α52(E6) Ser > Cys (TCT > TGT); HBA1: c.158C > G].
UNASSIGNED: The discovery of HBA2: C.400A > C expands the existing spectrum of α-globin variants. The carriers of simple heterozygous Hb Dongguan generally do not have obvious clinical symptoms. The information in this study will help clinicians understand the screening, molecular diagnosis and clinical significance of Hb variants.