Methods of prenatal screening for trisomy 21

Abstract

Methods for prenatal screening for trisomy 21 employ examination of the fronto-maxillary facial (FMF) angle of a fetus. In one embodiment, the methods comprise obtaining a two or three dimensional image of a fetal face, measuring the FMFbone angle on the image, and comparing the measured FMFbone angle with an FMFbone angle characteristic of chromosomally normal fetuses, wherein a measured FMFbone angle greater than the FMFbone angle characteristic of chromosomally normal fetuses provides an indication of an increased likelihood of the occurrence of trisomy 21 in the fetus. In another embodiment, the methods comprise obtaining a two or three dimensional image of a fetal face, measuring the FMFskin angle on the image, and comparing the measured FMFskin angle with an FMFskin angle characteristic of chromosomally normal fetuses, wherein a measured FMFskin angle greater than the FMFskin angle characteristic of chromosomally normal fetuses provides an indication of an increased likelihood of the occurrence of trisomy 21 in the fetus. In additional embodiments, both FMFbone angle and FMFskin angle are measured and compared with values characteristic of chromosomally normal fetuses.

Dependencies are inferred from the claim text.