The genetic component occurs because of the combined effect of mutated genes. The environmental factor is the lack of vitamins particularly folate during early pregnancy.
Checkpoints in a cell cycle are meant for the regulation for the proliferation of the cells. These checkpoints are basically present in the G1 and S phase of the cell cycle. The role of these checkpoints is to check for any DNA damage or other problem in the cell before proceeding in to the cell cycle. The reason behind this is to either correct the DNA damage or if it cannot be repaired to move the cell towards apoptosis. The tumor suppressor genes code for proteins which are involved in the repair of the damaged DNA in the cell cycle and initiation of apoptosis if the damaged DNA cannot be repaired to prevent the formation of abnormal cells. The proto-oncogenes act by stimulating the cell cycle by the formation of transcriptions factors which are responsible for the function of genes and by forming signal transducers which are responsible for the stimulus responsible for the initiation of the cell cycle.
Signal transduction is involved in the passing of signals to the nucleus of the cell for essential processes which include replication and transcription. Signal transduction occurs by the binding of a molecule to a receptor which may be located on the cell membrane or within the cell. This molecule carries signals and activates the receptor and brings about changes in the cell by sending signals which may lead to transcription. Increased signal transduction can result from mutations in genes that code for systems involved in carrying out signal transduction. This can lead to cancer because if signal transduction increases, the cells replicate and transcribe at a higher rate and are not under the normal regulatory control.
Children suffering from Down syndrome have very high chances of developing leukemia. Also patients who have leukemia along with Down syndrome have a