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Updated: Jan 26, 2026

FISH for Pre-implantation Genetic Diagnosis
Published on: February 23, 2011
[Molecular genetic diagnosis of a carrier with rare α-thalassemia mutations]
Qiang Ma1, Qingsong Liu2, Yan Cai2
1Department of Clinical Laboratory of the Affiliated Hospital, Translational Medicine Research Center, Department of Laboratory Medicine, North Sichuan Medical College, Nanchong, Sichuan 637000, China.
Objective:
To explore the cause of inconsistent genotypes for an α-thalassemia carrier by using two commercial genotyping kits.
Methods:
GAP-PCR and PCR-reverse dot blotting (PCR-RDB) were employed to determine the genotype of the carrier, while Sanger sequencing was used to verify the results.
Results:
Sequencing analysis demonstrated that the subject has carried a α1 globin gene with a 3.7 kb heterozygous deletion. In addition, two novel mutations, IVS-II-55(T>G) and IVS-II-119(G>TCGGCCC), were found in intron 2 of α2 globin gene.
Conclusion:
The two mutations located in the binding regions of PCR primers have caused failure of PCR amplification and misreading of the genotype. Combination of clinical and hematological phenotypes is indispensible to infer the genotype of carriers for accurate diagnosis.
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