Repronews #65: UK Biobank study finds over 60 genes involved in brain aging
UK insurer to offer polygenic scores for diseases; IVF success rate for PGT-M; women’s “child penalty” hurts fertility, especially in South Korea; does pronatalism distract from well-being?
Welcome to the latest issue of Repronews! Highlights from this week’s edition:
Repro/genetics
British insurer to offer polygenic risk scores for common diseases, including breast cancer, prostate cancer, cardiovascular disease, and type 2 diabetes
IVF success rates for couples using it for monogenic preimplantation genetic diagnosis (PGT-M) are higher than for those using IVF against infertility
Population Policies & Trends
The “child penalty”: the degree to which having a child lowers women’s employment is correlated with lower fertility (South Korea is ground zero)
“Chinese researchers argue funds for pronatalist policies would be better spent promoting “inclusive” well-being.
Genetic Studies
UK Biobank study of almost 39,000 people links brain aging to 64 genes, identifies 13 potential drugs to keep brain younger
Further Learning
Repro/genetics
British insurer to offer polygenic risk scores for common diseases (PET)
Bupa, a British health insurance and healthcare company, plans to offer polygenic risk scores for seven common diseases.
DNA from a person’s saliva sample is sequenced in a laboratory and analyzed via machine learning to assess the risk of developing each health condition. The conditions covered are breast cancer, prostate cancer, cardiovascular disease, type 2 diabetes, atrial fibrillation, high LDL cholesterol, high blood pressure, and low bone density.
The polygenic scores are integrated with other risk measures such as age, sex, and ethnicity to calculate how likely a person is—relative to others in a population whose DNA has also been sequenced and studied—to develop each condition.
Risk factors such as lifestyle, environment, and family history do not figure directly into these calculations.
“Each of us will be at high risk for a few diseases because of our genetics, but neither we nor our doctors know which ones,” said Professor Sir Peter Donnelly, co-founder and chief executive of Genomics plc, the company that developed the polygenic scores. “With genomic prevention we can now measure and understand those risks while a person is still healthy, years before any symptoms develop. This allows us to provide individuals with tailored advice on the steps they can take to live longer, healthier lives.”
This particular set of polygenic scores, known as Health Insights, is currently offered by a number of health insurers in the U.S. Following a pilot study of 300 people, Bupa will be the first insurance company to offer these scores in Britain.
Following obtention of British standards certification, the polygenic scores are expected to be made available to women over 40 and men over 45 as part of health risk assessment.
IVF success rates in individuals using PGT-M (JARG)
This study evaluates live birth rates per embryo transfer where the primary indication for assisted reproduction was preimplantation genetic testing for monogenic conditions (PGT-M).
Between 2015 and 2022, the laboratory biopsied and tested 2344 embryos for monogenic indications from 527 stimulated cycles.
513 embryos were transferred, resulting in 263 clinical pregnancies and 230 live births.
This meant clinical pregnancy and live birth rates per embryo transfer of 51.3% and 44.8%. By contrast, IVF patients with a subfertility factor were 48% less likely to achieve a clinical pregnancy per embryo transfer and 42% less likely to achieve a live birth.
The authors conclude individuals accessing PGT-M have higher clinical pregnancy and live birth rates than couples accessing IVF for subfertility, suggesting preimplantation genetic testing is an effective reproductive option.
More on repro/genetics:
Assisted Reproductive Technology (ART) Oversight: Lessons from the United States from Abroad (ASRM Center for Policy & Leadership)
Gates Foundation funds $5 million global study on male infertility (University of Birmingham)
Study: Men with better semen quality may live longer (PET)
Population Policies & Trends
“The impact of the child penalty on fertility: And the country where motherhood means quitting” (Boom)
The employment gap between women with and without children is known as the “child penalty.” A child penalty of 20% means on average a mother’s employment falls 20% behind a non-mother’s employment after having children
The extent of the child penalty varies hugely among high-income countries: in Norway 3%, Sweden 9%, the U.S. and France 25%, and South Korea 49%.
There is a negative correlation between a country’s total fertility and the child penalty in high income countries.
South Korea has the best-educated female workforce in the world (76% of women aged 25-34 have a tertiary qualification).
In spite of this, South Korea has the largest gender pay gap in the OECD and the female participation rate is 17.5 percentage points lower than the male (73.3% to 55.8%). This is the result of the child penalty: there is almost no gap between men and unmarried women without children.
In Europe, there is a negative correlation between conservative family values and birth rates (though this may be partly due to higher high-fertility, non-European immigration to more liberal Western European countries).
“Antinomy of pronatalist policies: It is time to shift focusing from population sustainability to population well-being” (JoME)
Chengmeng Zhang and Gong Chen of Peking University argue that pronatalist policies may exacerbate inequities by diverting resources from broader well-being.
UN data suggests even substantial pronatalist spending—as evidenced by South Korea’s $270 billion expenditure since 2008—fails to counter forces driving fertility decline, such as gendered labor disparities and single-person households.
The authors argue for a paradigm shift from population sustainability as “a relic of Malthusian anxieties” to population well-being. This would mean “prioritizing inclusive social services over demographic engineering.”
The authors argue for “the ethical imperative of reallocating resources towards underserved groups, whose marginalization is both a cause and consequence of pronatalism’s narrow calculus.”
More on population policies and trends:
“The couple who want to make America procreate again: Simone and Malcolm Collins are enthusiastic avatars for a new pronatalist movement” (Washington Post)
“Are babies in Denmark becoming relatively more Danish?” (Emil Kierkegaard)
Genetic Studies
“How fast your brain ages is affected by these 64 genes” (Nature)
A team of Chinese and Israeli researchers have identified 64 genes affecting how quickly a person’s brain ages.
The study used UK Biobank data of MRI brain scans and genomes of 38,961 people to identify the genes and suggest 13 potentially relevant drugs that have already been explored in clinical trials for their anti-aging effects.
“The study presents an important step toward developing genetic-based treatments for accelerated brain ageing,” says Agustín Ibáñez, a neuroscientist at Trinity College Dublin. “Experimental studies will be needed to test whether the proposed drugs can slow brain ageing.”
Ibáñez notes that most of the study participants are from European populations and it is “unclear whether the findings apply to more genetically diverse groups.”
The MRI scans were used to estimate the “brain age gap” (BAG) of individuals, the difference between the estimated biological brain age and chronological age.
The authors note that a growing body of evidence suggests brain aging is associated with decreased mental and physical fitness, as well as increased risk of neurodegeneration and mortality.
Further Learning
Human nature
“Fifty years of twin study: Five discoveries about nature and nurture from a landmark meta-analysis” (Steve Stewart-Williams)
“Top 20 Steven Pinker quotes” (Steve Stewart-Williams)
Biotech
“Five years on: how COVID was the catalyst for Africa’s genomic revolution” (Nature)
“Topical gene therapy for ‘butterfly children’ under review in EU” (PET)
Emily Clise Tully (Hoover Institution and Gingko Bioworks), “China is poised to dominate biotechnology in the 21st century” (The Hill)
“Make biology great again, Mr. President” (Steve Sailer)
Evolution
“An archaic European face more than one million years old” (Nature)
“Ancient DNA shows Stone Age Europeans voyaged by sea to Africa” (Nature)
“‘Impressive’ and ‘humbling’: Whale language skills equal and even surpass human speech capabilities in some ways” (Yahoo News/GLP)
“What will humans be like generations from now in a world transformed by AI?” (GLP)
Disclaimer: We cannot fact-check the linked-to stories and studies, nor do the views expressed necessarily reflect our own.