It is known that the de novo mutation rate among men and women is not the same and as paternal age increases so does the de novo mutation rate. Kong et al performed genome wide sequencing in 78 trios, among which there were 5 three-generation families. With this design they were able to calculate the average de novo mutation rate at 1.20â€‰Ã—â€‰10âˆ’8 per nucleotide per generation, and accurately count and attribute de novo mutations to each of the parents. More specifically they show that the maternal de novo rate stays stable or increases slightly while the paternal mutations are predicted to increase by 2 every year (if a linear fit is applied) or double every 16.5â€‰years (exponential fit). More data from men who fathered children at old age will be needed in order to verify which model is correct.
Periklis Makrythanasis, MD, PhD