Daily Endocrinology Research Analysis
Three impactful endocrinology studies stand out today: a large HAPO cohort analysis shows that gestational diabetes subtypes differentially predict neonatal and adolescent metabolic risks; a prospective multicenter genetic study demonstrates digenic inheritance in thyroid dysgenesis, reshaping the genetics of congenital hypothyroidism; and a mechanistic study identifies a JMJD8–PLIN2 axis that suppresses lipophagy, driving adipocyte hypertrophy and insulin resistance.
Summary
Three impactful endocrinology studies stand out today: a large HAPO cohort analysis shows that gestational diabetes subtypes differentially predict neonatal and adolescent metabolic risks; a prospective multicenter genetic study demonstrates digenic inheritance in thyroid dysgenesis, reshaping the genetics of congenital hypothyroidism; and a mechanistic study identifies a JMJD8–PLIN2 axis that suppresses lipophagy, driving adipocyte hypertrophy and insulin resistance.
Research Themes
- Precision stratification in gestational diabetes and offspring risk
- Digenic inheritance reshaping congenital hypothyroidism genetics
- Lipophagy regulation and adipocyte hypertrophy via JMJD8–PLIN2
Selected Articles
1. Digenic Inheritance Mode in Congenital Hypothyroidism Due to Thyroid Dysgenesis: HYPOTYGEN Translational Cohort Study.
In a nationwide prospective cohort with targeted sequencing and functional validation, 5.5% of thyroid dysgenesis cases exhibited digenic inheritance involving a thyroid development gene and DUOX2/DUOXA2, supported by segregation and in vitro assays. These findings redefine the genetic architecture of congenital hypothyroidism due to dysgenesis and argue for broader genetic testing and tailored follow-up.
Impact: Demonstrating digenic inheritance in CHTD challenges monogenic paradigms and directly informs genetic counseling, screening panels, and surveillance strategies.
Clinical Implications: Expand genetic testing to include combined assessment of thyroid development genes with DUOX2/DUOXA2; counsel families on digenic risk; plan long-term endocrine follow-up acknowledging syndromic malformation rates.
Key Findings
- Among 292 genotyped patients, 6.8% carried a pathogenic variant in one of 10 known CHTD genes.
- Digenic inheritance was identified in 16 patients (5.5%), combining a thyroid development gene variant with a DUOX2/DUOXA2 variant.
- Segregation analysis and in vitro functional studies supported the digenic model; cardiac (7.7%) and renal (3.9%) malformations were noted.
Methodological Strengths
- Prospective multicenter nationwide cohort with standardized newborn screening ascertainment
- Integrated approach combining targeted NGS, familial segregation, and functional assays
Limitations
- Genetic analysis performed in a subset (292/514) based on DNA availability and criteria, potentially introducing selection bias
- Targeted panel limits discovery of variants outside the 78 genes; functional studies focused on select pathways
Future Directions: Adopt exome/genome-wide approaches to capture additional digenic/oligogenic architectures; establish penetrance estimates and clinical algorithms integrating genotype for surveillance.
CONTEXT: Congenital hypothyroidism (CH) is the most common neonatal endocrine disorder and is chiefly caused by thyroid dysgenesis (CHTD). The inheritance mode of the disease remains complex. OBJECTIVE: Gain insight into the inheritance mode of CHTD. METHODS: Prospective multicenter nationwide translational study in France including 514 patients with CH diagnosed through systematic newborn screening (HYPOTYGEN cohort). We focused on CHTD cases and studied their clinical and molecular phenotypes. Targeted next-generation sequencing using a 78-gene panel, including genes involved in thyroid development, function, transport, metabolism and action of thyroid hormones. Statistical analysis, familial segregation, and in vitro functional studies focusing on cell migration have been performed. RESULTS: We analyzed the clinical phenotypes of 458 patients with CH. Cardiac and renal malformations were present in 7.7% (14/182) and 3.9% (7/178) of patients, respectively. Genetic analysis was performed on 292 patients of the cohort, based on criteria for ethnicity and availability of DNA samples for index cases and their parents. A disease-causing mutation in 1 of the 10 known genes for CHTD was identified in 20/292 (6.8%) patients. We found a digenic mode of inheritance in 16 (5.5%) patients, each carrying a variant in a thyroid development gene and a variant in the H2O2 generation complex gene DUOX2/DUOXA2. Familial segregation analysis and in vitro functional studies supported this model. CONCLUSION: This work expands our understanding of the molecular causes of CHTD by demonstrating that digenic inheritance can be implicated, with deleterious variants in thyroid development and DUOX2/DUOXA2 genes. The complexity of this model implies a revision of the genetic landscape of CHTD and specific clinical care of patients during long-term follow-up.
2. Subtypes of Gestational Diabetes Mellitus Are Differentially Associated With Newborn and Childhood Metabolic Outcomes.
In 7,970 neonates and 4,160 children from HAPO, insulin-resistant and mixed-defect GDM subtypes conferred greater risks of cord hyperinsulinemia, neonatal hypoglycemia (insulin-resistant), childhood obesity (OR 1.53), and impaired glucose tolerance (OR 2.21 and 3.01). Subtyping GDM by insulin physiology identifies offspring at highest metabolic risk.
Impact: This large, well-characterized cohort links maternal GDM pathophysiology to long-term offspring metabolic outcomes, enabling precision risk stratification and early prevention strategies.
Clinical Implications: Consider GDM subtype-based follow-up, prioritizing infants of insulin-resistant or mixed-defect GDM for early lifestyle interventions and metabolic screening into adolescence.
Key Findings
- All GDM subtypes were associated with large size at birth (birth weight and skinfolds >90th percentile).
- Insulin-resistant and mixed-defect GDM increased risk of cord C-peptide >90th percentile; insulin-resistant GDM increased neonatal hypoglycemia risk.
- Childhood obesity risk was higher with insulin-resistant GDM (OR 1.53), and impaired glucose tolerance risk was elevated with insulin-resistant (OR 2.21) and mixed-defect GDM (OR 3.01).
Methodological Strengths
- Large international cohort with standardized phenotyping and long-term offspring follow-up
- Robust multivariable modeling adjusting for maternal and child covariates
Limitations
- Observational design limits causal inference despite adjustments
- Subtype definitions rely on percentile cutoffs; residual confounding and center effects possible
Future Directions: Test targeted prenatal/postnatal interventions by GDM subtype; validate subtyping in diverse populations; integrate biomarkers to refine risk prediction.
OBJECTIVE: Subtypes of gestational diabetes mellitus (GDM) based on insulin sensitivity and secretion have been described. We addressed the hypothesis that GDM subtypes are differentially associated with newborn and child anthropometric and glycemic outcomes. RESEARCH DESIGN AND METHODS: Newborn and child (age 11-14 years) outcomes were examined in 7,970 and 4,160 mother-offspring dyads, respectively, who participated in the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study and HAPO Follow-Up Study. GDM was classified as insulin-deficient GDM (insulin secretion <25th percentile with preserved insulin sensitivity), insulin-resistant GDM (insulin sensitivity <25th percentile with preserved insulin secretion), or mixed-defect GDM (both <25th percentile). Regression models for newborn and child outcomes included adjustment for field center, maternal BMI, and other pregnancy covariates. Child models also included adjustment for child age, sex, and family history of diabetes. RESULTS: Compared with mothers with normal glucose tolerance, all three GDM subtypes were associated with birth weight and sum of skinfolds >90th percentile. Insulin-resistant and mixed-defect GDM were associated with higher risk of cord C-peptide levels >90th percentile. Insulin-resistant GDM was associated with higher risk of neonatal hypoglycemia. Insulin-resistant GDM was associated with higher risk of neonatal hypoglycemia and childhood obesity (odds ratio [OR] 1.53, 95% CI 1.127-2.08). The risk of childhood impaired glucose tolerance was higher with insulin-resistant GDM (OR 2.21, 95% CI 1.50-3.25) and mixed-defect GDM (OR 3.01, 95% CI 1.47-6.19). CONCLUSIONS: GDM subtypes are differentially associated with newborn and childhood outcomes. Better characterizing individuals with GDM could help identify at-risk offspring to offer targeted, preventative interventions early in life.
3. JMJD8 Regulates Adipocyte Hypertrophy Through the Interaction With Perilipin 2.
Proteomics identified PLIN2 as a JMJD8 binding partner. JMJD8 physically interacts with PLIN2 to inhibit PLIN2 phosphorylation, suppress fasting-induced lipophagy, and decrease energy production, thereby promoting adipocyte hypertrophy and insulin resistance.
Impact: This work uncovers a lipid droplet–centric mechanism linking a chromatin-associated protein to lipophagy control via PLIN2, nominating a druggable axis for obesity and insulin resistance.
Clinical Implications: While preclinical, targeting the JMJD8–PLIN2 interaction or restoring PLIN2 phosphorylation/lipophagy could represent new therapeutic avenues for obesity-related insulin resistance.
Key Findings
- Proteomics identified PLIN2 (perilipin 2) as a binding partner of JMJD8.
- JMJD8–PLIN2 interaction suppresses PLIN2 phosphorylation, inhibiting fasting-induced lipophagy and energy production.
- This axis drives adipocyte hypertrophy and insulin resistance by disrupting lipid droplet homeostasis.
Methodological Strengths
- Unbiased proteomics to discover binding partners, followed by mechanistic validation
- Clear linkage of protein–protein interaction to functional outcomes in lipid droplet biology
Limitations
- Preclinical mechanistic work; translational relevance and in vivo therapeutic modulation remain to be demonstrated
- Scope of model systems and species not detailed in the abstract
Future Directions: Validate the JMJD8–PLIN2 axis in vivo across species, define upstream regulators, and test pharmacologic modulators to restore lipophagy and improve insulin sensitivity.
New research builds on previous findings that JMJD8 mediates insulin resistance by promoting adipocyte hypertrophy. We identified PLIN2 as a binding partner of JMJD8 using proteomics approaches. This study reveals a physical interaction between JMJD8 and PLIN2, which plays a crucial role in driving adipocyte hypertrophy and insulin resistance. JMJD8 suppresses fasting-induced lipophagy and reduces energy production by inhibiting PLIN2 phosphorylation. These findings highlight the importance of JMJD8 and PLIN2 in regulating lipid droplet homeostasis and suggest a potential mechanism for controlling fat mobilization during energy deprivation.