rs367643250 — DYRK1B R102C

DYRK1B R102C — The Rare Kinase Mutation Behind Hereditary Metabolic Syndrome

DYRK1B¹¹ Dual-specificity tyrosine-phosphorylation-regulated kinase 1B — a serine/threonine kinase that regulates cell cycle exit, quiescence, and differentiation sits at a cellular crossroads: it puts dividing cells to sleep and shepherds them toward differentiated fates. In fat tissue, this means steering precursor cells toward full adipocyte differentiation. The R102C variant tips that balance hard in one direction, flooding carriers with fat-promoting signals they never should have received.

This variant is not a common risk factor — it is a rare, high-penetrance disease mutation. First described in a landmark 2014 New England Journal of Medicine study²² 2014 New England Journal of Medicine study
Keramati et al. A form of the metabolic syndrome associated with mutations in DYRK1B. NEJM, 2014, the R102C substitution was found to co-segregate perfectly with a devastating metabolic syndrome phenotype — dubbed AOMS3 (Abdominal Obesity-Metabolic Syndrome 3; OMIM #615812) — across three unrelated multigenerational families. Every carrier developed the syndrome; every non-carrier did not.

The Mechanism

The R102C mutation swaps arginine for cysteine at position 102, a residue within the kinase-like domain³³ kinase-like domain
The catalytic core of the DYRK1B protein that phosphorylates target proteins that is conserved across vertebrates. At the molecular level, the mutation impairs the HSP90/CDC37 chaperone-assisted folding⁴⁴ impairs the HSP90/CDC37 chaperone-assisted folding
The R102C protein shows enhanced CDC37 co-chaperone binding, indicating conformational instability of the kinase domain of the kinase domain, causing more than half of the mutant protein to accumulate in detergent-insoluble aggregates⁵⁵ detergent-insoluble aggregates
Approximately 50% of mutant DYRK1B vs ~10% of wild-type accumulates in insoluble cytoplasmic fractions within cells. Paradoxically — and critically — the soluble mutant fraction retains and potentiates gain-of-function effects on downstream targets.

The cellular consequence unfolds through two main channels. First, DYRK1B normally inhibits the SHH (Sonic Hedgehog) and Wnt signaling pathways⁶⁶ SHH (Sonic Hedgehog) and Wnt signaling pathways
Two developmental pathways that suppress fat cell differentiation when active. R102C potentiates this inhibition, removing the brake on adipogenesis and causing precursor cells to differentiate into fat cells faster and more completely. Cells expressing R102C show elevated PPARγ, C/EBPα, and C/EBPβ expression⁷⁷ PPARγ, C/EBPα, and C/EBPβ expression
Master transcription factors that drive adipocyte differentiation; elevated levels in patient-derived adipose stem cells carrying R102C — the master drivers of fat cell identity. Second, DYRK1B promotes expression of glucose-6-phosphatase (G6Pase)⁸⁸ glucose-6-phosphatase (G6Pase)
The enzyme that releases glucose from the liver into the bloodstream, a key target for diabetes drugs, the enzyme central to hepatic glucose output; the R102C variant further amplifies G6Pase expression, driving excess glucose release into the bloodstream and compounding insulin resistance.

The Evidence

The original Keramati et al. NEJM 2014⁹⁹ Keramati et al. NEJM 2014
Keramati AR et al. A form of the metabolic syndrome associated with mutations in DYRK1B. N Engl J Med, 2014 study identified the R102C mutation in three large multigenerational Iranian families. The mutation exhibited complete cosegregation¹⁰¹⁰ complete cosegregation
Every family member carrying the mutation had the full metabolic syndrome phenotype; none without it did with the disease phenotype and was absent in 2,000 ethnically-matched Iranian controls, 3,600 Caucasian US controls, and multiple large exome databases. The clinical phenotype was striking: heterozygous carriers developed central obesity, hypertriglyceridemia, low HDL cholesterol, type 2 diabetes, hypertension, and early-onset coronary artery disease — the full constellation of metabolic syndrome — typically before age 40.

A 2021 Orphanet study¹¹¹¹ 2021 Orphanet study
Mendoza-Caamal et al. Two novel variants in DYRK1B causative of AOMS3. Orphanet J Rare Dis, 2021 expanded the AOMS3 spectrum by identifying two further DYRK1B mutations in unrelated families, with the same autosomal dominant inheritance and full penetrance. Strikingly, affected members showed age-dependent progression¹²¹² age-dependent progression
Central obesity beginning in childhood, morbid obesity by the third decade, overt type 2 diabetes before 40, hypertension emerging in the fifth decade: central obesity begins in childhood, morbid obesity and hypertriglyceridemia develop before age 40, and hypertension emerges in the fifth decade. The 2022 adipose stem cell study¹³¹³ 2022 adipose stem cell study
Armanmehr et al. DYRK1B, PPARG, and CEBPB Expression in Adipose-Derived Stem Cells from Patients Carrying DYRK1B R102C. Metab Syndr Relat Disord, 2022 directly compared fat precursor cells from R102C patients versus healthy controls, confirming accelerated adipogenic differentiation at the transcriptional level.

Given the pathogenic classification in ClinVar, autosomal dominant inheritance, and complete penetrance, this variant warrants aggressive metabolic monitoring and intervention in carriers.

Practical Actions

Because DYRK1B R102C causes early-onset central adiposity and metabolic dysregulation through a defined genetic mechanism, carriers benefit from earlier and more intensive monitoring than the general population. Annual fasting lipid panels, glucose, HbA1c, and blood pressure checks from childhood or early adulthood are warranted. Pharmaceutical strategies that reduce hepatic glucose output (metformin) and improve insulin sensitivity (GLP-1 receptor agonists, SGLT-2 inhibitors) address the specific pathways disrupted by this variant. Dietary approaches that limit glycaemic load and saturated fat directly oppose the adipogenic and gluconeogenic overdrive caused by R102C.

Interactions

DYRK1B interacts with PPARγ (PPARG) biology — the R102C mutation drives elevated PPARγ expression, making the transcriptional target of thiazolidinedione drugs highly active. This raises the question of whether pioglitazone or rosiglitazone might paradoxically worsen adipogenesis in carriers. Clinicians managing AOMS3 carriers should be aware that standard insulin sensitizers designed to activate PPARγ may not behave as expected in this context. The interaction between DYRK1B gain-of-function and PPARG rs1801282 (Pro12Ala) genotype has not been studied but could modulate phenotype severity.