Abridge is partnering with top medical journals to bring in research for doctors to refer to during visits, pitting it against medical search giant OpenEvidence as more companies push to become all-in-one platforms for doctors.

…

The University of Southern California (USC) research team that identified the hormone-encoding gene GDF15 as a key driver of pregnancy sickness has identified nine additional genes linked to its most severe form, hyperemesis gravidarum (HG). Six of the identified genes had not been previously linked to the condition.

The Keck School of Medicine of USC team and international collaborators conducted a genome-wide association study (GWAS), scanning the entire genome for differences between women who developed HG during pregnancy and those who did not. They analyzed data from more than 10,000 women with the condition and more than 450,000 controls across European, Asian, African, and Latino ancestries. Their findings offer new clues about the condition and new hope for those affected.

Marlena Fejzo, PhD, a clinical assistant professor of population and public health sciences in the Center for Genetic Epidemiology at the Keck School of Medicine, led the present study and earlier research linking GDF15 to HG. Fejzo told GEN, “The study is much larger than previous studies and on a more diverse population allowing for identification of new genes associated with HG … The new genes give us new directions to explore for prediction, diagnosis, treatment, and response to therapies.”

Fejzo is first author of the team’s published report in Nature Genetics (“Multi-ancestry genome-wide association study of severe pregnancy nausea and vomiting”), in which the team stated, “Potential roles for candidate genes in appetite, insulin signaling, and brain plasticity provide pathways to explore etiological mechanisms and therapeutic avenues.”

HG, which affects about 2% of women, causes nausea and vomiting so severe that eating can become extremely difficult. “Most pregnancies are affected by nausea and vomiting (NVP), but in 0.3–10.8% of pregnancies the symptoms can be severe enough to cause maternal weight loss and adverse maternal and fetal outcomes,” the authors wrote. HG in its most severe form can even be life threatening.

HG was long misunderstood and often dismissed as psychological, growing evidence shows that it has a strong biological and genetic basis and can lead to severe malnourishment, putting both mother and baby at risk. Current treatments for HG are frequently ineffective in improving patient symptoms, the authors further pointed out, and so increase the risk of pregnancy termination, postpartum depression, and suicidal ideation, along with other maternal and offspring comorbidities. “Therefore, understanding of HG etiology is critical to begin to address the negative impact severe NVP has on maternal and child health.”

While historical hypotheses have previously centered around human chorionic gonadotropin (hCG), recent large-scale genetic studies have implicated the GDF15 gene encoding growth differentiation factor-15—a hormone associated with nausea and vomiting, the authors further pointed out. Earlier research by Fejzo and an international team had shown that the link between HG and GDF15 lies in women’s sensitivity to the hormone. They found that women exposed to lower levels of the hormone before pregnancy because of a mutation in the gene experience more severe symptoms, while women exposed to higher levels of the hormone before pregnancy have less severe nausea and vomiting symptoms.

“GDF15 was identified as the greatest genetic risk factor for HG in both a genome-wide and an exome-wide association study, and a rare mutation in GDF15 was associated with a greater than tenfold increased risk for HG,” the scientists noted in their newly reported study. Fejzo explained to GEN, “The mutation in GDF15 is rare. People who carry the mutation have abnormally low levels of GDF15 when they are not pregnant and that increases their risk of being hypersensitive to it during pregnancy when it is produced in massive amounts by the placenta.”

Commenting on their prior work implicating a role for GDF15 and HG, Fejzo further explained to GEN, “In our first GWAS study we found the association between the GDF15 gene and HG. Next, we published a whole-exome sequencing study that identified a mutation in GDF15 associated with HG. Then we published our study in Nature which provided strong evidence that hypersensitivity to the rise of GDF15 in pregnancy (due to low pre-pregnancy GDF15 in circulation) is the main driver of the condition.”

For their newly reported study the researchers carried out a multi-ancestry genome-wide association study of 10,974 HG/excessive vomiting in pregnancy cases and 461,461 controls across European, Asian, African, and Latino ancestries from nine contributing studies.

The results identified 10 genes that were linked to HG, including four that had previously been identified, and six new genes. “Because this is the largest study of HG ever conducted, we’ve been able to tease out important new details that were previously unknown,” said Fejzo. “The fact that we’ve studied women from multiple ancestry groups suggests that these results may be generalizable across a broad population.”

The four genes previously identified were growth differentiation factor 15 (GDF15), GFRAL, which produces the receptor for the GDF15 hormone of the same name, and IGFBP7 and PGR, both of which are involved in development of the placenta. The strongest link by far was to GDF15, which rises sharply during pregnancy. “We know that GDF15 and it’s receptor GFRAL are the main drivers and are in a signaling pathway that causes aversions, nausea, and vomiting,” Fejzo told GEN. “More work needs to be done to explore the other associations, but since studies suggest manipulating progesterone and/or IGFBP7 may not be safe in pregnancy, current studies are focusing on the GDF15 pathway.”

The six newly identified genes offer further clues that might help explain the basis of HG or point to new ways of treating it. They include FSHB, TCFL72 SLITRK1, SYN3, IGSF11, and CDH9. “Now that we’ve more than doubled the genes associated with HG, we can dig deeper into the biology behind this condition, as well as new possible pathways for treating it,” Fejzo said. Speaking to GEN, the researchers noted, “Because the new associations are novel, we need to understand the roles they may play in normal pregnancy and then compare that to pregnancies affected by HG.”

Of the newly identified genes, TCF7L2 stands out because it is one of the strongest genetic risk factors for type 2 diabetes and is also associated with gestational diabetes. “This is a brand-new target, and it’s not yet clear what it’s doing in pregnancy,” Fejzo said. In further commentary to GEN, Fejzo added, “The TCF7L2 gene is a type 2 diabetes-associated gene and a transcription factor that may control glucagon-like peptide-1 (GLP-1) expression and has been associated with liraglutide effects resulting in greater weight loss in obesity. So understanding its role in that rapidly evolving therapeutic arena has potential.”

Several of the other genes identified are involved in appetite and nausea, as well as brain plasticity, or how the brain learns and adapts to new information. Fejzo suggests the brain may learn to associate certain foods with feeling sick, leading to strong, lasting aversions during pregnancy. More research is needed to explore this possibility. “Other genes are associated with learning flexibility so we hypothesize that they may play a role in conditioned taste aversion and may provide new targets to alter or dampen learned aversions,” Fejzo told GEN. Historically, people believed the pregnancy hormone hCG was the cause, but we found no evidence to support that and instead, fascinatingly, we found a link to the follicle stimulating hormone receptor.”

Of the ten candidate genes six—GDF15, GFRAL, IGFBP7, PGR, TCF7L2 and SYN3—have been linked with cachexia—a wasting condition with similar symptoms to HG, including loss of appetite, weight loss and muscle wasting, the scientists noted. “Manipulation of GDF15, GFRAL, IGFBP7, PGR and TCF7L2 in animal models has shown effectiveness in reducing symptoms of cachexia. Thus, assuming analogous functions for these factors in HG, there is both genetic and biological support for causal and potentially reversible contributions for these genes in NVP.”

The researchers also found that some genes linked to HG were associated with other pregnancy outcomes. “This study also identified individual associations between risk genes and adverse outcomes including shorter pregnancy duration, pre-eclampsia, and birth weight,” they noted.

Several medications are available for treating HG, but even the most effective, Zofran, only partly relieves symptoms for about half of patients. The new findings reveal new potential treatment targets and could possibly also help match existing medications to patients based on their genetic profiles. “The ten genetic associations provide intriguing avenues to advance our understanding and pursue therapeutic pathways for a common pregnancy condition that in its most severe form is associated with substantial morbidity and even mortality for mothers and exposed offspring,” the scientists concluded.

Fejzo and her team just received approval to launch a clinical trial of metformin, a widely used diabetes medicine that increases GDF15 levels. The study will test whether taking metformin before pregnancy can desensitize women to the hormone, potentially reducing nausea and vomiting or preventing HG in women who have had it before. GEN was told, “We will be initiating a clinical trial to increase GDF15 prior to pregnancy in patients with a history of HG and planning to conceive to desensitize them to the hormone’s rapid rise in early pregnancy. We and others have shown preliminary evidence that this approach may work as in our retrospective study pre-pregnancy metformin use was associated with a significant reduction in HG risk.”

The post Pregnancy Sickness Study Identifies New Genetic Links appeared first on GEN – Genetic Engineering and Biotechnology News.

The FDA is taking the first step toward potentially backing popular peptides, convening advisors to discuss whether a handful of products should be given the go-ahead for compounding in the US.

A meeting of the …​ ​Read More