2023년 8월 8일
After earning a graduate degree in genetic counseling, Zoë Milgrom’s first job immediately exposed her to the difficult reality of putting her education into practice. In various obstetric and pediatric units at a major public hospital in Sydney, she supported families managing high-risk pregnancies or navigating diagnostic odysseys.
“I remember many family meetings where the neurologist or pediatrician had to deliver really awful news which had fatal implications for these beautiful babies,” she says. “I watched the parents’ hearts just hit the floor. On so many occasions it was left to me to tell them that, unfortunately, based on the information and the results, their child would not survive.” She developed relationships with these families and was often the person they called at the end.
One such relationship sparked her lightbulb moment. “It occurred to me that genetic testing and counseling is so powerful, and the impact it has on the individual who’s diagnosed, their family, and their community so all-encompassing, that it needs to be less taboo and feel less rare.”
Milgrom eventually left that hospital to work in a private fertility clinic. “Patients had more choices to preempt or avoid the loss. Yet there was still so much heartache that had led people to come into the clinic.”
As time went on and genomic sequencing decreased in price, Milgrom continued to ask, why is it so hard for people to access carrier screening? In Australia, couples can endure wait times of up to two years for genetic counseling and carrier screening tests.
During Milgrom’s own maternity leave, she met an entrepreneur named Kunal Kalro who was also passionate about making genetics accessible. They wanted to deliver clinical genetic testing and counseling to the general population. In 2017 they founded Eugene, and they started seeing clients for reproductive carrier screening the next year.
Screening made accessible
Eugene, which exists completely in the digital space, serves individuals in Australia and New Zealand. Clients go online to provide family history and book a genetic counseling appointment where they learn about the benefits and limitations of testing and review their information. The counselor orders the saliva test kit, which arrives in the client’s mail, and then gets sent to a lab. Finally, Eugene’s genetic counselors and geneticists review the lab results.
The results are delivered directly on a video call. According to Milgrom, it’s a quick conversation for the majority of clients. But for someone who is identified as having a higher chance of passing on a genetic condition, Eugene counselors will provide guidance and support; they also liase with the patient’s healthcare provider. Eugene counselors pride themselves on being able to communicate scientific information into options that clients can use to make informed decisions. The clients own their genetic information and the choices they make based on the results are theirs.
“Pregnancy is risky”
About 70% of people tested on an expanded carrier screening panel are found to be healthy carriers of at least one significant genetic condition. Those conditions are usually recessive and rarely have implications for the person being tested. Family history, Milgrom explains, is not a good predictor. In fact, 90% of children who are born with an inherited genetic condition have no family history of it.
About 2%–3% of couples1 tested are found to have a higher chance of having a child with a significant inherited genetic condition. This is where genetic counseling is crucial in reproductive carrier screening, because having this information can affect what choices the couple makes. “There are lots of choices out there,” Milgrom says, “and we really need to support the couples to feel empowered so they can make informed decisions, based on their own personal values and beliefs.”
Today, the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (better known as RANZCOG) recommends that anyone planning to become pregnant or in their first trimester should be made aware of the availability of reproductive carrier screening. In Australia the most common carrier screening test is a three-gene test, but Milgrom says it has lower detection rates for people of non-European ancestry, so expanded panels are a much more comprehensive way of identifying carrier couples, regardless of ancestry.
Diverse populations are underrepresented in the body of existing genomic data, which limits the scope of our knowledge of disease and the potential for precision medicine. Seventy-eight percent of the genome-wide association study data in the public GWAS Catalog comes from individuals of European descent. “If we’re moving towards the future of precision medicine, the genomic data needs to include people of diverse backgrounds,” Milgrom says.
About 90% of pregnant people will do another kind of screening, known as non-invasive prenatal screening, or NIPS (NIPT in the US). Milgrom notes that the different NIPS tests, which are often done in the first trimester, vary in terms of chromosomes tested, technology used, and accuracy level.
She adds that people confuse NIPS, which can be done each time a given person becomes pregnant, with carrier screening, which is typically only done once because it shows whether the parents could have a genetic condition to pass on. She says people are also quick to conclude that everything is fine after one all-clear genetic test result, when in fact, new genetic changes can happen during any pregnancy. “The most important thing to communicate to families is that no genetic screening test can provide definitive diagnosis or ever remove all risk. Pregnancy is risky. But there are ways to identify whether you’re in an increased risk group, so you can then make reproductive choices in an empowered and proactive way.”
Looking back at Eugene's first five years, Milgrom feels a great sense of pride in having helped couples across Australia and New Zealand on their path to parenthood.
“No one chose their DNA,” Milgrom says. “It’s what makes us who we are. So I have sort of a personal crusade to celebrate genetic diversity by making people know that we all carry variations in our DNA, and if we know about them we can choose whether we act on them or not.”
1Archibald AD, Smith MJ, Burgess T, Scarff KL, Elliott J, Hunt CE, McDonald Z, Barns-Jenkins C, Holt C, Sandoval K, Siva Kumar V, Ward L, Allen EC, Collis SV, Cowie S, Francis D, Delatycki MB, Yiu EM, Massie RJ, Pertile MD, du Sart D, Bruno D, Amor DJ. Reproductive genetic carrier screening for cystic fibrosis, fragile X syndrome, and spinal muscular atrophy in Australia: outcomes of 12,000 tests. Genet Med. 2018 Apr;20(5):513-523. doi: 10.1038/gim.2017.134. Epub 2017 Oct 26. Erratum in: Genet Med. 2018 Feb 01;: PMID: 29261177.
