In the face of the new scientific and technological revolution and the transformation of medical paradigms, the field of rare disease medicine, as a cross-disciplinary emerging discipline integrating basic research, clinical practice, drug development, and policy support, is experiencing unprecedented development opportunities. This paper systematically sorts out the disciplinary connotation, construction paths and practical challenges of the Department of Rare Diseases, and puts forward countermeasures and suggestions for promoting the high-quality development of this emerging discipline in China.

Neurodevelopmental disorders (NDDs) are a group of diseases caused by abnormal development of the brain and nervous system, mainly including global developmental disabilities/intellectual disabilities, autism spectrum disorders, attention deficit hyperactivity disorder, and others; at present, certain progress has been made in the research on common NDDs, and some effective therapeutic approaches have been developed, but for rare NDDs such as fragile X syndrome, Rett syndrome, and Dravet syndrome, the elucidation of their pathogenesis and the development of therapeutic strategies still face major challenges due to insufficient clinical samples, the complexity of the brain structure, and the limitations of existing research models. In recent years, induced pluripotent stem cells (iPSCs) technology has achieved breakthrough progress, where the directed differentiation of patient-derived iPSCs into neurons, glial cells, and cerebral organoids, combined with clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR associated protein 9 (Cas9) gene-editing technology, provides a novel research model for exploring the pathogenic mechanisms and therapeutic strategies of rare NDDs, and this paper reviews the research advances and challenges of iPSCs technology in the study of rare NDDs.

The construction of a training system for visiting physicians in the department of rare diseases in China is an important measure to improve the overall diagnosis and treatment capacity for rare diseases and address the critical challenge of insufficient knowledge and skills among clinicians in practice. This article systematically describes the visiting physician training system established by the Department of Rare Diseases at Peking Union Medical College Hospital. It summarizes the training objectives and positioning, design logic, and learning modules of the system, aiming to provide a reference for the construction of the specialized talent team for rare diseases in China.

With the continuous refinement of China's rare disease prevention and treatment policies, the diagnosis and treatment capacity for rare diseases in China has been steadily improved; however, delayed diagnosis, inadequate transition of care, and poor continuity of long-term management remain common, particularly in pediatric rare diseases. Pediatric rare diseases often arise during critical developmental stages and exhibit age-dependent phenotypic evolution, such that diagnostic delays may lead to the missing of critical intervention windows. As the leading institution of the Hubei Provincial Rare Disease Medical Center and the Rare Disease Quality Control Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology (hereinafter referred to as "Tongji Hospital") has established and implemented a rare disease discipline cluster model centered on platform convergence and specialty clustering. This model centers on the whole-life-cycle management needs of pediatric rare diseases, and constructs a systematic operational framework covering technical and data support, platform governance, specialized cluster operation, as well as regional and policy coordination. By summarizing the organizational pathway and practical effects of the rare disease discipline cluster construction at Tongji Hospital, this paper aims to provide a reference for general hospitals in promoting the development of rare disease diagnosis and treatment systems.

The development of the rare disease discipline is a crucial pathway for enhancing the diagnosis and treatment of rare diseases, cultivating specialized professionals, and fostering technological innovation. Currently, China' rare disease discipline is accelerating its development driven by both policy and demand. However, it still faces multi-dimensional challenges, including an incomplete clinical management mechanism, a shortage of interdisciplinary talents, a weak scientific research system, and limited outreach capacity. To address these challenges, this paper proposes and constructs an integrated development system with clinical diagnosis and treatment as the foundation, talent cultivation as the engine, scientific research as the support, and disciplinary outreach capacity as the extension. Specific strategies include: enhancing clinical management through artificial intelligence-assisted diagnosis systems and multidisciplinary collaboration platforms; strengthening the talent pool through textbooks, curricula, and hierarchical training mechanisms; bolstering research collaboration and translational outcomes by leveraging international data-sharing platforms, national rare disease medical centers, the State Key Laboratory of Complex Severe and Rare Diseases, and the National Key Scientific Infrastructure for Translational Medicine; and expanding grassroots outreach and public awareness through the National Rare Disease Diagnosis and Treatment Collaboration Network, the National Rare Disease Quality Control Center, and integrated media communication channels. In the future, the rare disease discipline should further deepen the integration of medicine and engineering, expand international cooperation, focus on the translational closed loop, improve the regional collaboration network, so as to build a more resilient and dynamic disciplinary ecosystem, and ultimately achieve a comprehensive improvement in the diagnosis and treatment of rare diseases.

A 51-year-old male presented with nasal obstruction, followed by progressive hearing loss and blurred vision. Imaging identified space-occupying lesions in the paranasal sinuses, orbits, and paraspinal regions, while laboratory tests confirmed positive anti-proteinase 3 anti-neutrophil cytoplasmic antibody(PR3- ANCA) immunoglobulin G (IgG)and markedly elevated serum IgG4. Despite treatment with corticosteroids, immunosuppressants, and radiotherapy, the patient exhibited steroid dependency with relentless disease progression. Following multidisciplinary consultation, a diagnosis of inflammatory myofibroblastic tumor (IMT) coexisting with ANCA- associated vasculitis (AAV) was favored, though IgG4-related disease remained a critical differential. Ultimately, profound immunosuppression precipitated a severe herpesvirus infection, leading to disseminated intravascular coagulation and multiple organ dysfunction syndrome. This case underscores the rarity and diagnostic complexity of concurrent IMT and AAV, highlights the therapeutic dilemma of balancing primary disease control against fatal opportunistic infections, and emphasizes the critical role of multidisciplinary collaboration in the diagnosis and treatment of complex diseases.

Gorham-Stout disease(GSD) is a rare osteolytic disorder characterized by spontaneous and progressive osteolysis, along with abnormal angiogenesis and lymphangiogenesis, with no new bone formation. We present a case of a 15-year-old female admitted due to " recurrent right leg pain for 5 years, 11 months after undergoing right femoral fracture surgery". Through comprehensive integration of the patient's clinical phenotype, laboratory tests, imaging findings, pathological examinations, and molecular biological test results, GSD was considered highly likely. A multidisciplinary treatment approach was conducted, including a combination of zoledronic acid and sirolimus to inhibit osteolysis, along with rehabilitation training and orthopedic intervention, providing a personalized and comprehensive treatment strategy.

Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disorder primarily caused by pathogenic variants in the TSC1 or TSC2 genes. It is characterized by multisystem hamartomatous lesions and neuropsychiatric manifestations. Here we report a young male patient with TSC involving multiple organs, caused by a heterozygous frameshift mutation in TSC2 (c.2071delC, p.Arg691Alafs^*7). The patient initially presented with classic facial angiofibromas and hypomelanotic macules, and subsequently developed psychiatric and behavioral disturbances with auditory hallucinations. Neuroimaging revealed an intracranial mass lesion, which was confirmed as a subependymal giant cell astrocytoma on postoperative histopathology following surgery performed at an outside institution. After admission, the patient underwent a comprehensive diagnostic workup, and multidisciplinary treatment evaluation revealed extensive multisystem involve-ment, including the nervous system, skin, kidneys, lungs, heart, eyes, pancreas, liver and bones. Combined with relevant literature, this article discusses the molecular mechanisms, clinical phenotypes, and comprehensive management of TSC, in order to provide a reference for the standardized and individualized management of this disease.