Human Genetic Survey Identifies 148 Different Genetic Loci Impacting Cognition
Some people have normally higher cognitive functioning than many others. These individual differences are rather persistent across the entire life span from after childhood onwards. People with greater measured overall cognitive functioning have a tendency to survive longer and be deprived.
Maintaining overall cognitive functioning is an important element of aging. The people variance in this medically- and – socially-important trait has genetic and environmental aetiologies. The specifics of the genetic gifts are, as-yet, badly known.
Now, a brand new survey by researchers based at Johns Hopkins University, says that there are 43,162 genes, of which 21,306 are protein-coding genes and 21,856 are noncoding genes.
Through the means of combining cognitive and genetic data from the CHARGE and COGENT consortia, and UK Biobank, they found 148 genome-wide significant independent loci associated with general cognitive function.
“Our total gene count,” noted the study, “corresponds to the total number of distinct chromosomal intervals, or loci, that encode either proteins or noncoding RNAs; in addition, we report the total number of gene variants, which includes all alternative transcripts expressed at each locus.” After assembling sequences from 9,795 RNA sequencing experiments, collected from 31 h
uman tissues and hundreds of subjects as part of the Genotype-Tissue Expression (GTEx) project, Dr. Salzberg’s team counted a total of 323,824 transcripts, for an average of 7.5 transcripts per gene.“Our expanded gene list includes 4,998 novel genes (1,178 coding and 3,819 noncoding) and 97,511 novel splice variants of protein-coding genes as compared to the most recent human gene catalogs,” the bioRxiv article indicated.
“We detected over 30 million additional transcripts at more than 650,000 sites, nearly all of which are likely to be nonfunctional, revealing a heretofore unappreciated amount of transcriptional noise in human cells.”
The team additionally detected significant genetic overlap between general cognitive function, reaction time, and many health variables including eyesight, hypertension, and longevity. In conclusion, the team says, they identified novel genetic loci and pathways contributing to the heritability of general cognitive function.
“Although [this catalog] represents only a modest increase in the number of protein-coding genes (1,178, or 5.5% out of 21,306 total),” the article’s authors noted, “it more than doubles the number of splice variants and other isoforms of these genes, to 267,476.” The authors added that their findings suggest that the cell is a fairly inefficient machine, one that transcribes more DNA into RNA than it needs.
“Based on the results described here,” the authors concluded, “it appears that nearly 99% of the transcriptional variety produced in human cells has no apparent function, although most of these variants appear at such low levels that they cumulatively account for only 32% of transcriptional volume.”
