Richard Rava of Verinata Health and colleagues announced the first successful noninvasive technique for determining chromosomal defects in unborn children from their mother’s blood in the Jan. 10, 2013, issue of The American Journal of Human Genetics.
Massively parallel sequencing (MPS) of fetal DNA in the mother's blood offers a safer alternative for the detection of chromosomal abnormalities across the fetal genome.
Rava’s research proves that MPS is just as accurate at detecting chromosomal abnormalities in the fetus as metaphase karyotypes or chromosome microarray but has the advantage of not requiring any intrusion on the amniotic sac or removal of placental blood. Chromosome microarray provides a higher level of genetic information than metaphase karyotypes.
All three methods can be used to detect abnormalities associated with developmental delay, intellectual disability, congenital defects, and autism.
MPS provides a safer alternative particularly for women who may be prone to miscarriage.
MPS is portable. The procedure only requires a blood draw from the mother and the ability to maintain the integrity of the sample in transport to a facility that can perform the analysis. This advantage makes MPS a suitable alternative to metaphase karyotypes or chromosome microarray techniques in countries where the equipment is not readily available or accessible.
The research was reviewed at the Eureka Alert website the date of publication.
Details of accompanying photograph.
This clinical sample has a karyotype with a small deletion in chromosome 7 (blue circle). Another small deletion is detected in chromosome 8 (red circle). Expanded regions show z7j and z8j 1 Mb and 100 kb bin data. The figure shows a 1 Mb deletion at bin number 150 Mb on Chr 7 (A). At higher resolution (B), this deletion is found to be 300 kb long, in the region from 150.3 Mb to 150.6 Mb of Chr 7. Note: The putative copy-number gain seen in Chr 7 at bin number 156 in the 1 Mb data is not seen in the same region in the 100 kb data. The figure also shows a 2 Mb deletion on Chr 8 (A) covering bins 46 Mb and 47 Mb. At higher resolution (B), this resolves into a 900 kb deletion, covering the region from 46.9 Mb to 47.7 Mb of Chr 8.
Credit: American Journal of Human Genetics, Srinivasan et al. Figure 4. Usage Restrictions: Credit Required