For Clinicians

Your most common questions, answered.

On the science

What is a genetic risk score?
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Most diseases have a genetic component. Genetic risk scores quantify the degree of risk conferred through an individual’s genes.

The human genome contains several million genetic markers that commonly vary across individuals and influence the risk of common diseases. Individually, each of these associated single nucleotide polymorphisms (SNPs) has a small impact on disease risk. Their combined effect, calculated as a polygenic risk score (PRS), is frequently the best genetic estimate of disease risk, providing more predictive value than any single gene marker alone [1, 2]. Genetic risk scores often outperform traditional clinical risk factors like smoking, BMI, and family history [3, 4]. This is a new development, over the last 5 years genome sequencing has become more affordable, allowing study sizes to grow to the order of hundreds of thousands of individuals. These larger study sizes provided large amounts of data and afforded the development of more accurate genetic risk scores [5].

Learn more about genetic risk scores through a visual explainer.
http://polygenicscores.org/explained/

How is this different from the genetic tests I usually order?
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Orchid tests for genetic susceptibility to the most common conditions based on many genes instead of rare genetic disorders caused by single genes.

Historically, clinical genetics has focused on identifying rare genetic variants that diagnose a rare genetic disease. Monogenic diseases such as cystic fibrosis or spinal muscular atrophy can be diagnosed by interrogating genetic variation within single genes. These conditions may have autosomal dominant, autosomal recessive, or X-linked inheritance patterns. These are the tests that are usually ordered by physicians for individuals at risk of an inherited mutation, or as part of preconception or prenatal counseling. 

However, the vast majority of diseases are not controlled by the presence or absence of a single gene. Most common disease susceptibility is governed by small changes in dozens to millions of locations across the genome.

A genetic risk score aggregates the effects of tens to thousands of genetic variants that mediate their effects through many genes: this is what is meant by a “polygenic” disease architecture.

Learn more about our tests on our Science Page.

Why are these results reported as a “risk” number?
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An elevated genetic risk score identifies individuals with a genetic susceptibility to a disease of interest, however it is not a diagnosis of a disease.

While anyone can develop any of these conditions, genetics can tell us whether an individual has a combination of certain genetic markers that increase or decrease susceptibility to these conditions. Genetic risks are similar to other risk factors — a smoking history makes an individual more likely to develop lung cancer, for example.

Knowing this information can help individuals proactively manage their health and if desired, seek mitigation strategies to lower genetic risk for their future children, thus decreasing risk of disease development.

How is a genetic risk score developed? How is it validated?
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Statistical geneticists develop genetic risk scores using cohorts of hundreds of thousands of individuals who have sequence data paired with physician verified diagnoses.

Statistical tests are performed to find variants that are found in cases (individuals with the disease of interest) at higher rates than in controls (individuals without the disease of interest). 
This study design is called a genome-wide association study (GWAS). There is no single way to develop a polygenic risk score model, but the process generally involves:

  1. Reducing the impact of potential confounding variables. In this case, non-genetic factors like age, socioeconomic status, or geography

  2. Identifying a set of genetic variants with a strong association to the disease outcome

  3. Quantifying the extent to which each genetic variant either increases or decreases disease risk

Once a genetic risk score has been developed, it must be tested on a separate population that has also been sequenced and has physician verified diagnostic records. This is known as a “validation dataset” and helps answer the question: “is this genetic risk score as predictive on this population as it was on the original cohort used to develop the model?”

How predictive is a genetic risk score? What’s the evidence?
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Using data from hundreds of thousands of individuals, we see that individuals with an elevated genetic risk for a particular condition are 2 to 5 times more likely to develop that given condition than the average population.

This diagram shows the increased fold risk of disease development for individuals at the top 3% of genetic risk for each condition.

We continually review the latest research in genomics — identifying results that meet our stringent quality standards. We only incorporate results reproduced by several research groups and based on population sizes of more than 10,000 individuals.

Learn more about our tests on our Science Page.

On the Clinical Actionability

How can Orchid embryo screening add to current IVF clinical practice? 
Our Embryo report measures genetic predisposition for common conditions not included in other embryo genetic testing.

Currently, embryo testing involves the ability to screen for aneuploidy, monogenic conditions, and structural rearrangements. These tests are known as PGT-A, PGT-M, and PGT-SR, respectively. PGT-A is included in Orchid’s test and is applicable to any couple, while PGT-M and PGT-SR are done for specific clinical indications.

What conditions can Orchid screen for?
For the first time ever, parents can safely and naturally reduce their future children’s riskfor the top 10 most common diseases.
  1. Breast Cancer

  2. Prostate Cancer

  3. Coronary Artery Disease

  4. Atrial Fibrillation

  5. Ischemic Stroke

  6. Type 2 Diabetes

  7. Type 2 Diabetes

  8. Inflammatory Bowel Disease

  9. High BMI

  10. Schizophrenia

  11. Alzheimer's

Besides reporting on genetic risks for common conditions, our embryo report also evaluates the number of chromosomes within each embryo. This is commonly referred to as preimplantation genetic testing for aneuploidy (PGT-A).

What action as a clinician can I take based on Orchid’s embryo screening results?
Results can help clinicians like you counsel patients on which embryos have the highest genetic potential of a healthy offspring.

A reproductive endocrinologist will be able to use the results of Orchid’s genetic risk assessment of embryos to assist with patient decision-making in embryo selection. The patient and physician can use this information to make an informed decision about which embryo to consider transferring first, based on the results of the report.

What other genetic tests does Orchid offer beyond embryo screening?
Orchid also offers preconception testing that screens and identifies couples expected to have children with elevated genetic risk for a specific condition.

Much like carrier screening, preconception testing identifies “at risk” couples who may choose to mitigate their future child’s genetic risk through embryo creation,  screening and selection.  

Learn more about our preconception report.

How is this useful if my patients do not have enough high-quality embryos to transfer?

We recognize that there is a subset of patients with a limited number of blastocysts available for biopsy. In these patients, the utility of using advanced embryo screening for embryo selection will be limited. 

At the same time, there is a growing number of couples seeking IVF treatment at younger ages, for reasons beyond infertility — fertility preservation, genetic screening, LGBTQ family building are rapidly growing indications for IVF procedures. Many of these patients create multiple high-quality embryos in a given IVF cycle. In these scenarios, embryo screening may be suitable as a planning tool to provide future parents choice over chance. As with any tool, your clinical judgement is vital to help serve your patients best.

Does Orchid provide support to help my patients understand their results?
Yes. Orchid includes a personalized video walk through with a board-certified genetic counselor with every report.

Orchid reports come with online result review scheduling that patients love. Orchid reports include the most comprehensive genetic information available, that will satisfy the most discerning clientele and keep your practice competitive with the top centers around the world.

What relative risk reductions can Orchid achieve?

Genetic risk reductions vary depending on the genetic architecture of the condition and the genetics of each individual couple. Some couples are at risk of having children in the top 10% of genetic risk, or above the 90th percentile, for a certain common condition.

We aim to help understand the genetic risk of individual embryos to, if available, prioritize transfer of embryos with lower genetic risks.

How are all these conditions “prioritized” in each embryo?
Orchid’s genetic risk assessment priority is based on deprioritizing embryos with:

1. Chromosomal abnormalities
2. Increased genetic predisposition for common conditions

Typically, we do not find that couples are at high genetic risk for multiple conditions at once. This means that it is rare for an embryo to have significantly increased genetic predispositions relative to baseline risk for two conditions or more. 

In the rare case that a couple is identified to have embryos with elevated genetic risk for multiple conditions, determining the couple's values is critical to develop an embryo selection plan that best supports patient autonomy.

Will reducing genetic risk for one condition come at the cost of increased genetic risk for another condition?
It is uncommon for mitigation of one condition to incur a tradeoff of increasing genetic risk for another condition. Orchid focuses on mitigating risk for embryos in the highest percentiles of genetic risk.

To better understand why this is, here is the relationship between the prevalence rate of a condition (what fraction of individuals are affected with the disease) and the percentile of the genetic risk score. As you can see below, the curve is largely flat (indicating a small change in risk), up until the 90th percentile, where a sharp increase in risk emerges. While the curve and numbers vary slightly by condition, this pattern applies to all conditions tested.

What happens if there’s a discrepancy between morphology-based grading and Orchid’s genetic assessment of the embryos?

The genetic health assessment provided on Orchid’s embryo report is available to help you make an informed decision about which embryo to consider transferring first. It does not preclude the transfer of embryos with a higher genetic risk. 

Embryo transfer decision-making is ultimately driven by the reproductive endocrinologist’s and embryologist’s recommendations and patients’ desires. These decisions are often made on a discretionary case-by-case basis.

What patients would not be good candidates for Orchid testing?

We recommend excluding couples that are expected to have 3 embryos or fewer suitable for preimplantation genetic testing. We do not expect to provide substantial genetic prioritization utility for such couples.

Can Orchid support non-disclosure embryo screening?

Yes. Couples can opt to receive embryo results unmasked or blinded. If the couple opts for blinded non-disclosure, they are still able to transfer the healthiest embryo based on Orchid’s genetic prioritization technology, without revealing the contents of the report. If a child is born from that embryo, he or she may opt to unmask the results after age 18.

On the Ethics

How is a child born with Orchid’s genetic reports impacted?
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Our mission is to help couples give their future children the best shot of a healthy life. In many cases, embryo screening is able to substantially reduce potential genetic risks for the next generation.

If a couple, who pursues embryo screening, only has embryos with elevated genetic risk for specific conditions, and elects to transfer such an embryo, the information can guide proactive management if the development of the condition does occur. Increased awareness, screening, and lifestyle modifications can potentially help prevent or identify conditions early.

What about the ethics of selection against adult-onset disease?
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Orchid is deeply invested in operating at the highest ethical and scientific standards. Our mission is to help couples give their future children the best shot of a healthy life, without inheriting a predisposition to disease. 

Prevention of adult-onset disease through embryo screening and IVF is not new. Adult-onset disorders now represent over 20% of all preimplantation genetic testing for monogenic disorders (PGT-M) cases, with the most common indication being for cancer predisposition syndromes (Rechitsky & Kuliev, 2019).

Over the last 20 years, the field has advanced from the detection of very rare mutations to the capability to measure genetic susceptibility for common conditions. From a reproductive freedom perspective, we stand for a couple’s right to have access to information that enables them to mitigate disease risk for their future child.

Will this technology increase health disparities based on socioeconomic status?
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Orchid is committed to expanding access to our technology to every couple that can benefit. We advocate for expanded access through insurance coverage and self-insured employers incorporating our technology into their plans. In addition to these efforts, we have a low-cost program that patients can apply for here.