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Published on: October 20, 2019
Fetal rhd genotyping from maternal plasma in a population with a highly diverse ethnic background
Isabela Nelly Machado1, Lilian Castilho, Jordão Pellegrino
1Departamento de Tocoginecologia da Universidade Estadual de Campinas e Hemocentro Unicamp, Universidade Estadual de Campinas, Campinas, SP. imachado@fcm.unicamp.br
Objective:
To establish the performance of conventional PCR as a noninvasive method for fetal genotyping, by free fetal DNA analysis of distinct RHD regions from maternal plasma, in a population of a diverse ethnic origin.
Methods:
We conducted a validity of the diagnostic test by analyzing 81 plasma samples from RhD-negative Brazilian pregnant women, from 4 to 41 gestational weeks. We tested for exon 10 and intron 4 gene regions by allele specific-PCR. Fetal RHD genotyping by PCR on maternal plasma was compared to serologic RhD typing in the neonatal period.
Results:
Samples were obtained as follows: 15 in the 1st, 37 in the 2nd and 29 in the 3rd trimester. General accuracy was 97.3%, sensitivity of 98.3% and specificity of 93.8%.
Conclusions:
Conventional PCR is an accurate method for fetal RHD genotyping on maternal plasma, even in a population of mixed ethnic origin.
