| 摘要 |
A method for detecting foetal chromosomal aneuploidy for a chromosome of interest from a maternal sample (e.g. cell free DNA from plasma) comprises obtaining sequence information for both foetal and maternal DNA from the maternal sample, determining the number of sequence tags for the chromosome of interest and for a specific reference chromosome (or a relevant segment thereof), using said numbers of sequence tags to calculate a first normalised chromosome value against the first reference chromosome or chromosome segment (i.e. a ratio) to determine the presence, absence or no result for foetal aneuploidy. Preferably the normalised values are compared against a threshold value and statistically tested. Four or more aneuploidies such as trisomies T21, T18, T13 or monosomy X may be tested for simultaneously; alternatively, partial aneuploidies may be detected. |
