Traits: the small, specific things your file can say about you
The genuinely fun category — and, as it happens, the one containing some of the most solid single-gene findings in the whole report. Traits are where genetics is easiest to verify against your own experience.
What are DNA traits?
Everyday characteristics that turn substantially on one or a few well-understood variants: whether you digest lactose as an adult, whether alcohol makes you flush, how quickly you clear caffeine, whether coriander tastes of soap. They are the readings you can check against your own life, which is part of the appeal.
That checkability is also the best sanity test available for a service like this. If a report tells you that you are unlikely to flush from alcohol and you turn red after half a glass, you have learned something useful about the report.
Which traits can be read from a raw DNA file?
Thirteen in the full report, eight of them listed below: lactose tolerance, alcohol flush, caffeine metabolism, bitter taste sensitivity, coriander aversion, earwax type, photic sneeze and body-clock preference. Most rest on named, well-replicated variants, which is unusually strong ground for consumer genetics — and unusually easy to check against your own life.
| What we look at | Markers |
|---|---|
| Lactose tolerance | MCM6 / LCT |
| Alcohol flush | ALDH2 |
| Caffeine metabolism | CYP1A2 |
| Bitter taste | TAS2R38 |
| Cilantro aversion | OR6A2 |
| Earwax type | ABCC11 |
| Photic sneeze | — |
| Body clock | — |
Five further traits are covered in the report and not shown here. The eight above are the ones we put on the site, because they are the ones people can check against their own experience.
How reliable are DNA trait results?
It varies sharply, and the variation is worth knowing. Alcohol flush from ALDH2 and lactose tolerance from MCM6 are close to definitive. Body-clock preference and photic sneeze draw on many small effects and are much weaker. The same report contains both, so we mark which is which.
A trait resting on one variant with a large effect can be read confidently. A trait resting on dozens of variants with tiny effects can only ever be a tendency, and any service presenting the two with equal confidence is telling you something about the service.
The other categories
- Medicines How inherited differences change the way people process common medicines, which genes a consumer DNA file covers, and the two that it cannot read reliably at all.
- Family planning What being a carrier means, which recessive conditions a consumer DNA file covers, and why a clear result is not an all-clear.
- Nutrition Which nutrition and wellness markers a consumer DNA file covers, how strong the evidence behind them is, and why a blood test still beats a genotype.
- Fitness What a consumer DNA file can suggest about power versus endurance, response to training, injury predisposition and recovery — and the limits of all four.
- Ancestry How an ancestry breakdown is computed from a consumer DNA file, what mtDNA and Y haplogroups add, and why two services reading the same file disagree.