Human functional genetic studies are biased against the medically most relevant primate-specific genes.
BACKGROUND
Many functional, structural and evolutionary features of human genes have been observed to correlate with expression breadth and/or gene age. Here, we systematically explore these correlations.


RESULTS
Gene age and expression breadth are strongly correlated, but contribute independently to the variation of functional, structural and evolutionary features, even when we take account of variation in mRNA expression level. Human genes without orthologs in distant species ('young' genes) tend to be tissue-specific in their expression. As computational inference of gene function often relies on the existence of homologs in other species, and experimental characterization is facilitated by broad and high expression, young, tissue-specific human genes are often the least characterized. At the same time, young genes are most likely to be medically relevant.


CONCLUSIONS
Our results indicate that functional characterization of human genes is biased against young, tissue-specific genes that are mostly medically relevant. The biases should not be taken lightly because they may pose serious obstacles to our understanding of the molecular basis of human diseases. Future studies should thus be designed to specifically explore the properties of primate-specific genes.
Hao
Lili
L
CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, 100029 Beijing, China.
Ge
Xiaomeng
X
Wan
Haolei
H
Hu
Songnian
S
Lercher
Martin J
MJ
Yu
Jun
J
Chen
Wei-Hua
WH
D000375:Aging; D000818:Animals; D035843:Biomedical Research / Q000592:standards*; D015870:Gene Expression / Q000235:genetics*; D015894:Genome, Human / Q000235:genetics*; D006801:Humans; D011323:Primates / Q000235:genetics*; D011506:Proteins / Q000235:genetics*
D011506:Proteins