Recent Episodes
Left Handers Rule
Sometimes I feel like an alien. Why? I am very left-handed. I can’t do anything with my right hand. While this can give me the upper hand (ha!) in tennis, the reality is most of the world is backwards to me. Same for one of my children who had to learn the downsides of being a south paw.
Scientists have learned a few things about left handers. Your chances of being left-handed go up if one of your parents is, but you’re still more likely to be a righty. Only a quarter of left-handed children have left-handed parents. And only 10 percent of people in the world are lefties. Just 1 percent is ambidextrous, meaning they can use both hands. Which hand you favor is a complex trait involving genes and the environment. Twin studies suggest only a quarter of handedness is genetic while the rest comes from a child’s surroundings.
One of those genes may have been found by a new study using the UK Biobank, which contains a large set of genomic data for biomedical research. They compared 300,000 right handers with 30,000 left handers.
They found that a rare variant of the TUBB4B gene was three times more present in left handers, but not all of them had it. Other genes may be involved, but we also already know that factors outside genetics have a larger influence. They vary greatly including testosterone levels in the womb, low birth weight, societal pressures, right hand tools along with many other impacts.
As a left-hander I get to say this – despite some disadvantages, left-handers Rule!
More Information
This Specific Gene Could Be the Reason You’re Left-Handed
Scientists identified a rare genetic variant coding for a protein that may be partially responsible for left-handedness.
Genes play a very small role in determining left-handedness, research finds
NPR's Ayesha Rascoe speaks with Clyde Francks, a geneticist in the Netherlands, about the latest research into what makes people left or right-handed.
Exome-wide analysis implicates rare protein-altering variants in human handedness
Handedness is a manifestation of brain hemispheric specialization. Left-handedness occurs at increased rates in neurodevelopmental disorders. Genome-wide association studies have identified common genetic effects on handedness or brain asymmetry, which mostly involve variants outside protein-coding regions and may affect gene expression. Implicated genes include several that encode tubulins (microtubule components) or microtubule-associated proteins. Here we examine whether left-handedness is also influenced by rare coding variants (frequencies ≤ 1%), using exome data from 38,043 left-handed and 313,271 right-handed individuals from the UK Biobank.
