Rare syndromes highlight the intricate interplay between genetics and metabolism. In the pediatric context, Pietrzykowska et al. conducted a systematic review on cystic fibrosis-related diabetes (CFRD) in patients receiving CFTR modulators, reporting that these therapies may improve glucose tolerance and insulin secretion in children and adolescents with preserved β-cell function, although evidence remains limited and variable 6. This signals the need for larger pediatric trials with standardized metabolic outcomes to determine the long-term glycemic benefits of CFTR modulation 6.At a molecular level, monogenic diabetes provides mechanistic insight that informs both diagnosis and therapy. Rare monogenic variants account for approximately 1-5% of all diabetes cases, and accurate recognition is crucial for implementing effective personalized management 2,3. In this context, mitochondrial dysfunction and endoplasmic reticulum (ER) stress have emerged as key convergent pathways impairing β-cell function, disrupting insulin secretion, and contributing to glycemic dysregulation 7. Ozsu et al. summarize current understanding of these mechanisms, emphasizing how mitochondrial defects and ER stress can serve as diagnostic clues and targets for future therapeutic strategies 2.Maturity-Onset Diabetes of the Young (MODY) exemplifies the clinical and genetic heterogeneity of monogenic diabetes. Misdiagnosis as T1D, T2D, or gestational diabetes remains common, often delaying optimal therapy by years 8,9. In the Research Topic, the study from a Latin American tertiary center highlights that whole-exome sequencing is crucial to identify pathogenic variants and reclassify diabetes type accurately, enabling individualized therapy 8. Complementing this, Gulisano et al. describe an adolescent with an HNF4A variant whose diagnosis of MODY1 allowed a successful transition from insulin to sulfonylurea therapy, greatly improving glycemic control and quality of life 9.Clinical vigilance remains essential, as atypical presentations may serve as early clues. Syndromic features may precede or signify complex disease. For example, a case of Klinefelter syndrome presenting with diabetic ketoacidosis underscores how chromosomal abnormalities may underlie metabolic disturbances and should prompt comprehensive diagnostic evaluation 5. Dermatologic manifestations of diabetes are also frequent clinical indicators: up to one-third of patients can develop skin lesions such as necrobiosis lipoidica, bullosis diabeticorum, and diabetic dermopathy, which can precede systemic complications and signal underlying metabolic dysregulation 6,10. Early recognition facilitates timely diagnostic testing and targeted therapy, enhancing outcomes and quality of life 6,10.Pregnancy adds further complexity to diagnosis and management. While hyperglycemia during gestation is most commonly attributable to gestational diabetes, a portion of cases reflects underlying autoimmune or monogenic forms. Autoantibody screening can identify women at risk for progression to T1D after pregnancy, guiding individualized insulin therapy and follow-up 4,7. In this vein, two contributions in this Topic address type 1 diabetes diagnosed during pregnancy and diabetic mellitus associated with Wolfram Syndrome type 1 (WS1). The latter highlights how reproductive outcomes in WS1, including successful cases managed with hybrid closed-loop insulin pumps, require coordinated care integrating advanced technologies with genetic insight 7.Therapeutic innovation continues to expand the diabetes care landscape. Continuous intraperitoneal insulin infusion (CIPII) has emerged as a potent approach in patients with unstable T1D and subcutaneous insulin resistance, promoting more physiologic hepatic insulinization and reducing postprandial glycemic variability compared with traditional subcutaneous insulin therapy 3. Concurrently, hybrid closed-loop systems are increasingly applied to complex patients, bridging the gap between physiological insulin requirements and real-world glycemic challenges 7.Immune checkpoint inhibitor-related diabetes mellitus (ICI-DM) represents an important example of iatrogenic diabetes arising from cancer immunotherapy. Characterized by fulminant hyperglycemia, frequent ketoacidosis, and autoantibody positivity, ICI-DM underscores how genetic predispositions and immune modulation intersect to trigger rapid β-cell failure 10. Early recognition of ICI-DM and timely insulin initiation are critical to prevent acute metabolic decompensation, while ongoing research seeks to clarify the optimal approach to cancer immunotherapy continuation in affected patients 10.Across these diverse presentations, a consistent theme emerges: early and precise diagnosis informed by genetics, careful clinical evaluation, and molecular insights is indispensable. Precision medicine approaches-leveraging modern sequencing technologies, advanced insulin delivery systems, and tailored pharmacologic interventions-offer the potential to optimize clinical outcomes and enhance quality of life for patients with rare diabetes forms 1235678910. As diabetes prevalence continues to rise globally, the ability to recognize subtle clinical clues and apply individualized therapeutic strategies will be central to effective care 1,5,18.The studies collected in this Research Topic underscore the diversity and complexity of rare diabetes forms. Clinicians must look beyond the traditional dichotomy of "type 1 or type 2" and maintain a high index of suspicion for alternative diagnoses; this will enable early genetic and molecular characterization, integration of novel interventions, and application of advanced technologies. Moving forward, larger multicenter trials and collaborative registries are essential to refine diagnostic algorithms, elucidate epidemiological patterns, and assess the long-term efficacy of targeted therapies 1,2,5,8,15. Ultimately, these advances pave the way for a precision medicine framework in diabetes care, ensuring that even the rarest forms receive optimal, individualized management 1,2,[5678910.
Grancini et al. (Fri,) studied this question.