Rapid detection of -alpha 4.2 deletion of alpha-thalassemia-2 by polymerase chain reaction.
We sequenced part of the X boxes of alpha-thalassemia-1 of Southeast Asia type (- -SEA) with -alpha 4.2, -alpha 3.7, -alpha G-Taichung, and alpha CS alpha. We found the X box of -alpha 3.7 belonged to the X box of alpha 2 globin gene and the X box of alpha CS alpha contained X boxes of both alpha 1 and alpha 2 globin gene, whereas the X box of -alpha 4.2 and -alpha G-Taichung was a hybrid of X boxes of alpha 2 and alpha 1 globin gene. We also found there are two types of -alpha 4.2 deletion; type 1 is a common type of -alpha 4.2 deletion and type 2 is linkage to -alpha G-Taichung. We used a combination of two methods, the amplification refractory mutation system (ARMS) and the amplified created restriction sites (ACRS), to amplify the hybrids of X boxes specifically. The upstream primer for X box of alpha 2 globin gene was designed following the standard ARMS procedure to amplify the X segment of the alpha-globin gene. The downstream primer was designed according to the ACRS method to check the specificity of PCR products. Using this approach, we can diagnose the different types of -alpha 4.2 deletion. This kind of approach can also be used to amplify the specific region from the cluster of highly homologous genes.
Chang
J G
JG
Department of Molecular Medicine and Clinical Pathology, Taipei Municipal Jen-Ai Hospital, Taiwan.
Liu
T C
TC
Chiou
S S
SS
Chen
J T
JT
Chen
T P
TP
Lin
C P
CP
D001483:Base Sequence; D004247:DNA / Q000032:analysis / Q000235:genetics; D017353:Gene Deletion; D005914:Globins / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D016133:Polymerase Chain Reaction; D017085:alpha-Thalassemia / Q000235:genetics*
D005914:Globins; D004247:DNA