Same‐day prenatal diagnosis of common chromosomal aneuploidies using microfluidics‐fluorescence in situ hybridization

Abstract

Rapid molecular prenatal diagnostic methods, such as fluorescence in situ hybridization (FISH), quantitative fluorescence-PCR, and multiplex ligation-dependent probe amplification, can detect common fetal aneuploidies within 24 to 48 h. However, specific diagnosis or aneuploidy exclusion should be ideally available within the same day as fetal sampling to alleviate parental anxiety. Microfluidic technologies integrate different steps into a microchip, saving time and costs. We have developed a cost-effective, same-day prenatal diagnostic FISH assay using microfluidics. Amniotic fluids (1-4 mL from 40 pregnant women at 15-22 weeks of gestation) were fixed with Carnoy's before loading into the microchannels of a microfluidic FISH-integrated nanostructured device. The glass slides were coated with nanostructured titanium dioxide to facilitate cell adhesion. Pretreatment and hybridization were performed within the microchannels. Fifty nuclei were counted by two independent analysts, and all results were validated with their respective karyotypes. Of the 40 samples, we found three cases of fetal aneuploidies (trisomies 13, 18, and 21), whereas the remaining 37 cases were normal. Results were concordant with their karyotypes and ready to be released within 3 h of sample receipt. Microfluidic FISH, using 20-fold less than the recommended amount of probe, is a cost-effective method to diagnose common fetal aneuploidies within the same day of fetal sampling.

Evaluation of Microfluidics-FISH method in prenatal diagnosis

“…In our study Microfluidics-FISH proved to be an accurate and cost-effective rapid testing method of common aneuploidies, what is also consistent with results published by Yo et al [8]. Chromosomal aberrations, existing in 20% of investigated samples, have been identified correctly by all methods in all but one case, in which fetus was diagnosed with sSMC.…”

“…The same problem was encountered in aforementioned study by Yo et al [8]. In such cases, a higher concentration of pellet was needed and loading process had to be repeated.…”

Rapid Diagnosis of Aneuploidy Using Segmental Duplication Quantitative Fluorescent PCR

“…This method avoids the need to culture cells and reduces the time required for diagnosis. However, this technique is relatively labor intensive and requires technical expertise, requirements that prevent the efficient processing of a large number of samples in clinical diagnostic settings [20],[21]. These drawbacks have encouraged the development of more rapid and efficient methods for the detection of fetal chromosomal aneuploidies.…”

FlashFISH™: a novel technique for rapid diagnosis of aneuploidies in dysmorphic neonates

“…However, these methods are unable to produce results within the same day of sample collection due to technical limitations. FlashFISH ™ is a FISH-based technique that combines microfluidics to enable the detection of common chromosomal aneuploidies within hours of sample receipt [8]. We described our experience in the use of FlashFISH ™ in six newborns with clinically suspected genetic syndromes.…”

“…Carnoy's fixative (3:1 methanol:glacial acetic acid) was added and the fixed MNCs were washed twice with Carnoy's fixative before loading into the microfluidic FISH-integrated nanostructured device (microFIND ® slides, Tethis S.p.A, Milan, Italy) [9]. FlashFISH ™ was performed and microscopic enumeration of signals was as previously described [8].…”