Traits Prediction - Information

Traits Predictions menu

The trait prediction menu page shows the available traits and your predictions. We ask that you first answer a short survey before viewing your prediction.
Additional traits will be added periodically.

Traits Prediction Report Example

A report page for each trait contains three main sections.
First, your predicted score based on the uploaded genotype file and published research:

Second, a report of how the genetic variants of the genotype file are involved in determining the predicted score.

Third, a table with detailed information about the most significant genetic variants from the genotype file.

Read below for explanations about each section.

Frequently Asked Questions

In the menu page, what does the Please Complete Survey message mean? (top)
Before you view your results, we ask that you fill a survey that will allow us to conduct further research. As the questions may be related to your genetic prediction results, the survey must be completed before seeing your report so that responses are not biased.
In the menu page, what does Confidence mean? (top)
This is the variance explained by the SNPs included in our analysis, and can be interpreted as the fraction of your prediction that is determined by the genetic variants that have been discovered. Because almost all human traits are determined by a combination of our genomes and environment, the prediction only takes into account the genomic component, and your trait may further be determined by your environment. Additionally, in almost all complex traits a large fraction of genetic variants thought to contribute an effect have yet to be identified, so these predictions represent only our best guess based on current genomic knowledge.
For more technical information see the Fraction of Variance Unexplained Wikipedia Page .
In the menu page, what does the Survey Submitted column mean? (top)
We have a short survey attached to each trait that will appear when you first enter a report. The results of these surveys will help us validate our genetic predictions.
In the trait report, why are columns in the table empty? (top)
These columns are empty if they are not reported in the research paper on which our scores are based. They are not based on your score directly.
In the trait report, how do I interpret the effect sizes histogram? (top)

BLUE bars represent the maximum potential effect.
If the BLUE bar extends to the right of the 0.0 line, the SNP has potential to increase the predicted score.
If the BLUE bar extends to the left of the 0.0 line, the SNP has potential to decrease the predicted score.
If the BLUE bar extends to both sides, the SNP has potential to both increase and decrease the predicted score.
Information about BLUE bars is determined from published research.

RED bars represents the contribution of your genotypes to the predicted score.
If the RED bar extends to the right of 0.0 line, this raises your score relative to the average.
If the RED bar extends to the left of 0.0 line, this lowers your score relative to the average.
Information in RED bars comes from your genotype file.

In the example histogram to the left:

rs1: This SNP has the potential to increase your trait score (blue bar extend to the far right), but you either do not possess the effect allele, or the effect allele is highly common in your ancestry group (red bar extends only a little).

rs2: You possess the maximum possible effect contributed by this SNP.

rs3: This SNP has the potential to decrease your trait score, and your genotype results in a modest effect.

rs4: The effect of this SNP on your trait score can be either positive or negative depending on your ancestry group, and it contributes a small positive effect to your prediction.

This plot shows the effect contributed by each SNP to your prediction. For each SNP, this effect is determined by how many effect alleles you possess (0, 1, or 2), the effect size of the SNP, and the frequency of the effect allele in your ancestry group. Each bar on the y-axis represents one SNP. The x-axis represents the effect of the SNP and can be interpreted as a distance in standard deviations from the mean trait score on a standard normal distribution. For example, one standard deviation when predicting height amounts to about 6.5 cm.

The blue bar represents the maximum possible effect an individual can experience from a single SNP, though the vast majority of people may not see this effect. The red bar represents your effect from this SNP. When the red bar eclipses, the blue one, this means you possess the maximum effect of this SNP in either the positive or negative direction for the trait, given your alleles and ancestry. Above are some common scenarios you will see in your reports. The definition of a 'positive' effect depends on the trait - this could mean a taller predicted height, or a higher likelihood of having a genetic disorder.

The effect sizes histogram displays at most 30 SNPs with the largest contributions to your score. This means that different users may see different SNPs displayed, and that many of the SNPs will be homozygous (as homozygous SNPs commonly contribute to a larger effect).
Your prediction score is always calculated using the full set of known associated SNPs, which may number in the hundreds.

In the trait report, what does my ancestry group under Frequency mean? (top)
Our predictions take into account varying allele frequencies between populations in order to cancel out baises introduced by population stratification. The allele frequencies are taken from the 1000 Genomes Project and are grouped into five broad ancestry categories. The allele frequencies from one of these groups are applied to your predictions based on your inferred ancestry.
In the trait report, what is an Effect Size? (top)
An effect size is attached to one allele of each SNP in our report. It is the amount in standard deviations that your trait score is expected to change if you have that particular allele. These effect sizes are summed together based on your SNP profile, and are then adjusted according to population distributions to produce your final prediction.
In the trait report, what is an Odds Ratio? (top)
The odds ratio is a representation of the effect size of a SNP that is commonly used in case-control genetic studies. For example, a geneticist may conduct a study on two groups: those who have cancer, and those who do not. If a particular allele has a very high odds ratio, then the odds (or probability) of an individual with one or two copies of the allele is highly elevated compared to an individual who has no copies of the allele.
In the trait report, what is a Standard Error? (top)
Theses values pertain to the effect sizes of the SNPs, and are extracted from the research papers that report these SNPs. They indicate how confident the researchers are in the particular effect size, and how much this effect size is expected to differ based on measuring different samples. The lower the standard error, the more confident in the effect size.
In the trait report, what is a P-value? (top)
This is the result of a hypothesis test on the value of the effect size of a SNP. A low P-value means that the SNP is more likely to be involved in determining the trait in question. A common threshold P-value used to determine significance in genome-wide association studies is 5 * 10-8.
What if my prediction is wrong or inaccurate? (top)

Traits prediction based on genetic information is complicated by a wide variety of factors, including environmental effects, population stratification and statistical uncertainty, among other causes. Some of the predictions shown might be inaccurate. To keep improving our prediction models we ask our users to complete a preliminary survey - these surveys will enable us to refine our predictions.

If your prediction is inaccurate - we will use the valuable information you've provided in the survey to improve our future prediction models.

For any questions, please contact DNA.Land.