When to Conceive? Ask Father Time.

Many inherited diseases involve mutations in genes that are present in every parental cell and are passed via that parent's sperm or egg to the child. But how often does a de novo mutation occur only in a germ cell, with the result that the mutation is passed to the child but is absent in the parent's nongerm cells? And can such mutations lead to disease? Using rapid gene sequencing technology (JW Gen Med Dec 30 2005), researchers in Iceland sequenced the genomes of parent-child trios in 78 families in which children had autism, schizophrenia, or other illnesses, and in 1900 healthy controls. Comparing gene sequences in children and their parents allowed identification of all de novo mutations.

The number of de novo mutations in a child depe…