Prenatal and pediatric
testing | Absolute Q

Identify genetic mutations faster with digital PCR

Overview

Rare genetic conditions have a distressing impact on pediatric healthcare from difficult-to-diagnose inherited diseases to transplant rejection during treatment. To improve patient outcomes, causative and prognostic genetic indicators need to be identified quickly and reliably.

Digital PCR (dPCR) provides a sensitive and quantitative approach to detecting gene deletions, copy number variations (CNVs), single nucleotide polymorphisms (SNPs), and more. Because of its sensitivity, dPCR can detect specific target loci at very low concentrations, making this technique particularly suitable for applications in cell-free fetal DNA (cffDNA) and graft-derived cell-free DNA (gcfDNA). 

Combinati’s Absolute Q dPCR platform offers unparalleled multiplexing, testing speed, and ease of use delivering improved outcomes for reproductive health and genetic disease.

Determine severity of Spinal Muscular Atrophy in 90 minutes

Spinal muscular atrophy (SMA), a recessive neuromuscular disorder, causes severe atrophy and is the leading genetic cause of infant death after cystic fibrosis. SMA is caused by loss of the SMN1 gene, but disease severity differs based on copy number of the closely-related SMN2 gene. dPCR can detect a wide range of SMN1 and SMN2 copy numbers more accurately than other quantitative PCR techniques, providing important prognostic information. Combinati’s 4-color multiplexing capabilities allow for simultaneous testing of SMN1 and SMN2 with an 90-minute turnaround time, streamlining SMA testing for research applications.

 Download: SMA app note

Quantitatively measure allelic activity in acute lymphoblastic leukemia

Preferential allelic imbalance (PAI) causes disease-associated SNPs to be preferentially retained and may be associated with disease severity in acute lymphoblastic leukemia (ALL), the most common childhood cancer. Allelic skew, in which a disease-associated allele is expressed more strongly, can also influence phenotypes of ALL and other cancers. Tumor PAI can be detected by Sanger sequencing and SNP genotyping but neither technique is quantitative. Allelic skew can be measured by RNA sequencing, but the amplification step involved in library preparation can severely bias the results. Both PAI and allelic skew could be quantitatively detected using Combinati’s Absolute Q dPCR platform. Because all of the steps necessary for dPCR are integrated into a single instrument, one technician could perform tests for PAI and allelic skew without additional training.

Conduct non-invasive prenatal testing for multiple diseases at once

Prenatal testing can be used to screen for chromosomal disorders, such as downs syndrome and fragile X syndrome, as well as for diseases caused by more subtle genetic mutations, such as hemophilia and muscular dystrophy. Traditional screening approaches require the withdraw of amniotic fluid or extraction of placental cells. cffDNA can be sampled non-invasively, but the assays traditionally used to test cffDNA—massively parallel sequencing and microarrays—are expensive and time consuming. In the last few years, several publications have demonstrated that dPCR can be reliably used for non-invasive screening of cffDNA. Combinati’s Absolute Q dPCR platform, which has four optical channels, could thus be used for non-invasive prenatal testing of up to four different genetic diseases simultaneously.

Predict/detect transplant rejection before it escalates

Childhood leukemia patients are often prescribed bone marrow grafts. Rejection of these grafts can have life-threatening repercussions. In order to decrease the likelihood of rejection, transplant patients are often also prescribed immunosuppressive drugs.

The detection of graft-derived cfDNA in the plasma, which is excreted by necrotic or apoptotic cells, can be used to monitor the effects of immunosuppressive drugs as well as transplant rejection.  Combinati’s multiplexed approach to digital PCR, paired with a rapid testing turnaround time, makes the Absolute Q an ideal platform for studying graft integrity and rejection response.