Partial mole withblive foetus

D/D
1. Partial mole: triploidy
2. Twin gest one healthy and other complete mole
3. Placental mesenchymal dysplasia
4. Chorioangioma

Biochemical genetics

GC/MS
Principle:
Separates components in a mixture (by GC) and do molecular analysis by mass spectroscopy (by MS)

mixture will separate into individual substances when heated. The heated gases are carried through a column with an inert gas (such as helium). As the separated substances emerge from the column opening, they flow into the MS. Mass spectrometry identifies compounds by the mass of the analyte molecule. A library of known mass spectra, covering several thousand compounds, is stored on a computer.