AccuCopy quantification combined with pre-amplification of long-distance PCR for fast analysis of intron 22 inversion in haemophilia A.
BACKGROUND
To develop a digitalized intron 22 inversion (Inv22) detection in patients with severe haemophilia A.


METHODS
The design included two tests: A genotyping test included two multiplex pre-amplification of LD-PCR (PLP) with two combinations of five primers to amplify wild-type and chimeric int22h alleles; a carrier mosaicism test was similar to the genotyping test except only amplification of chimeric int22h alleles by removing one primer from each of two combinations. AccuCopy detection was used to quantify PLP products.


RESULTS
PLP product patterns in the genotyping test allowed identifying all known Inv22. Quantitative patterns accurately represented the product patterns. The results of 164 samples detected by the genotyping test were consistent with those obtained by LD-PCR detection. Limit of detection (LOD) of the carrier mosaicism test was at least 2% of heterozygous cells with Inv22. Performing the test in two obligate mothers with negative Inv22 from two sporadic pedigrees mosaic rates of blood and hair root of the mother from pedigree 1 were 8.3% and >20%, respectively and negative results were obtained in pedigree 2.


CONCLUSIONS
AccuCopy quantification combined with PLP (AQ-PLP) method was confirmed to be rapid and reliable for genotyping Inv22 and highly sensitive to carrier mosaicism detection.
Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
Qianlan
Q
Ding
Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
Xi
X
Wu
Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
Yeling
Y
Lu
State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Shanghai, China.
Changming
C
Chen
Genesky Diagnostics (Suzhou) Inc., Suzhou, Jiangshu, China.
Rui
R
Shen
Genesky Diagnostics (Suzhou) Inc., Suzhou, Jiangshu, China.
Xi
X
Zhang
Genesky Diagnostics (Suzhou) Inc., Suzhou, Jiangshu, China. Electronic address: zhengwenj@geneskies.com.
Zhengwen
Z
Jiang
Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China. Electronic address: wangxuefeng6336@hotmail.com.
Xuefeng
X
Wang
D007446:Chromosome Inversion / Q000235:genetics*; D005260:Female; D005838:Genotype; D006467:Hemophilia A / Q000175:diagnosis / Q000235:genetics*; D006801:Humans; D007438:Introns / Q000235:genetics*; D008297:Male; D016133:Polymerase Chain Reaction
Factor VIII; Haemophilia A; Intron 22 inversion; Mosaicism