Mutation screening and prenatal diagnosis of a pedigree with Glanzmann's thrombasthenia

Abstract

Mutation screening was performed in a pedigree of Glanzmann's thrombasthenia (GT) and prenatal diagnosis was performed. In this study, reverse transcription-PCR-sequencing and PCR-sequencing, as well as restriction fragment length polymorphism(RFLP) and A/T-cloned-sequencing, were used to screen the ITGA2B and ITGB3 mutation in a pedigree with Glanzmann's thrombasthenia in the RNA and DNA level. Prenatal diagnosis was performed for this pedigree. Deletion of 99 bps was found in the cDNA of the patient in the pedigree, leading to deletion of 33 codons (from codon 160 to 192). After genomic analysis, the patient was found to be a compound heterozygote of c.374C to G mutation and intron 4(IVS-4) + 5 G to C mutation. The two mutations were inherited from the parents. IVS-4 + 5 G to C mutation was a point mutation in the splice site, while c.374C to G mutation was out of the splice site. But both of them resulted in the same splice pattern in RNA. The two mutations were novel mutations which have not been reported in Human Gene Mutation Database (HGMD) and the mutation data base of Glanzmann's thrombasthenia. The results of ITGB3 gene screening is normal in the proband and his parents. Two novel mutation, c.374C to G and IVS-4 + 5 G to C were found in this study, which might be the cause of GT in the pedigree.