A Double Marker Test is a blood test used to check for chromosomal abnormalities in a developing foetus.
Human beings have 23 pairs of chromosomes (one from the father and one from the mother to make up a pair). Each pair is labelled as chromosome 1, chromosome 2, chromosome 3 and so on through chromosome 23.
Any fewer or extra chromosomes lead to genetic abnormalities in the progeny:
Down’s syndrome is a genetic abnormality wherein there’s an extra copy of chromosome 21.
An extra copy of chromosome 18 causes Edward’s syndrome.
An extra copy of chromosome 13 causes Patau’s syndrome.
A Double Marker Test helps detect Down’s syndrome, Edward’s syndrome and Patau’s syndrome in a developing foetus.