As readers of these pages know, I always react when people, in discussing obesity, dismiss genetics as a cause with the statement to the effect, ‘our genes just don’t change.’ On other pages, I recite evidence that this just isn’t true. Our genes do change. I also notice that you never hear a genetics expert make this claim. And for a good reason, our knowledge of genetics changes every week.
Now comes a new study using genomic databases from Iceland. The study of 78 trios of mother, father and child, looking for mutations in the child’s genes which were not present in either parent and therefore must have arisen spontaneously in the egg, sperm or embryo. Fathers passed on nearly four times as many new mutations as mothers, 55 v. 14. The older the father, the greater the number of mutations. Most of the mutations may be harmless but some are linked to conditions like autism and schizophrenia. NatureNews:Fathers bequeath more mutations as they age
Maternal obesity and metabolic conditions have been linked to autism in their offspring PubMed: Maternal Metabolic Conditions and risk of autism. Likewise, schizophrenia has been linked to obesity, diabetes and inflammation PubMed: Schizophrenia, metabolic syndrrome and inflammation
Bottom line: while the increasing age of the father may be relevant for autism research, the point for obesity genetics may be that both mothers and fathers pass on spontaneous mutations to their child. Our genes are changing.