An observational study in Neuronal Intranuclear Inclusion Disease (NIID), sponsored by Sichuan Academy of Medical Sciences. Recruiting at 1 site in China. Per ClinicalTrials.gov, last updated 2026-06-26.
Sponsored by Sichuan Academy of Medical Sciences · Observational
This study aims to understand how differences in the NOTCH2NLC gene affect the symptoms and course of neuronal intranuclear inclusion disease (NIID), a rare inherited neurological disorder. NIID is caused by an abnormal expansion of a GGC DNA repeat in the NOTCH2NLC gene, but members of the same family can have very different repeat sizes and patterns, leading to a wide variety of problems-such as difficulties with memory, movement, sensation, or involuntary body functions. The main goal is to uncover how these genetic differences (repeat length and interruption pattern) contribute to the severity and type of symptoms.
The study is being conducted at Sichuan Provincial People's Hospital and will enroll approximately 12 individuals from a single family, including those diagnosed with NIID, family members who carry the genetic change but are not yet sick, and healthy relatives. Participants must be 18-85 years old, able to complete genetic testing and a small skin biopsy, and willing to provide informed consent. Those who are medically unstable or otherwise unable to participate will not be enrolled.
The study has both a retrospective part (collecting past medical records) and a prospective follow-up. At the beginning, all participants will have a physical exam, provide a blood sample (for long-read DNA sequencing and RNA sequencing), and undergo a 3-mm skin biopsy to look for disease-related protein deposits. Brain MRI and nerve/muscle electrical tests will also be performed if not done recently. After this baseline visit, everyone will be followed every 6 months for a total of 2 years (5 visits total). Each follow-up visit includes assessments of thinking, memory, movement, autonomic function, pain, and quality of life, along with a neurological exam and repeat imaging/electrical tests as needed. At the final 24-month visit, another blood sample will be taken for RNA sequencing to see how gene activity changes over time.
This is an observational study; there is no experimental treatment. Participants will be compensated a total of ¥3,000 across all visits for their time and travel. All data and samples will stay in China and will not be shared internationally.
Sichuan Academy of Medical Sciences is the lead sponsor of 16 studies on the registry; 9 are open to participants now.
Counted across the registry records on this site, refreshed daily.
This study will enroll approximately 12 participants from a single family (pedigree) with NOTCH2NLC-related neuronal intranuclear inclusion disease (NIID). The study population comprises three categories of family members: individuals with a clinical diagnosis of NIID, asymptomatic carriers of the NOTCH2NLC GGC repeat expansion, and healthy relatives who do not carry the expansion. All participants are adults aged 18 to 85 years recruited from the Health Management Center of Sichuan Provincial People's Hospital in China. Given the rarity and genetic nature of the disease, this single-family design is intended to control for shared genetic background and environmental factors while examining the effect of different GGC repeat characteristics on clinical phenotype.
Exclusion Criteria:
This is a single observational cohort consisting of approximately 12 members of the same family affected by neuronal intranuclear inclusion disease (NIID) caused by GGC repeat expansions in NOTCH2NLC. The cohort includes individuals with clinically diagnosed NIID, asymptomatic carriers of the repeat expansion, and healthy relatives without the expansion. After informed consent, all participants will undergo baseline assessments including clinical evaluation, peripheral blood collection for long-read and transcriptome sequencing, a skin punch biopsy for immunohistochemistry, and brain MRI/neurophysiological tests if clinically indicated. Participants will be followed prospectively every 6 months for 2 years (5 visits total). Follow-up visits include cognitive, motor, autonomic, and quality-of-life assessments, along with neurological examination and repeat imaging/electrophysiology as needed. A second blood sample for transcriptome sequencing will be collected at the 24-month visit. No
Other: No Intervention: Observational Cohort
This is an observational study. No investigational drug, device, biologic, or procedure is administered. Participants receive only standard clinical assessments, genetic testing, skin biopsy, and regular follow-up evaluations as described in the protocol.
Clinical Severity Score and Its Correlation with NOTCH2NLC GGC Repeat Characteristics
The primary outcome is a composite clinical severity score that integrates cognitive function (assessed by Mini-Mental State Examination \[MMSE\] and Montreal Cognitive Assessment \[MoCA\]), motor function (including extrapyramidal and pyramidal signs), autonomic function (e.g., orthostatic blood pressure changes, heart rate variability), and peripheral nerve function (based on nerve conduction studies and clinical examination). Each domain is rated on a standardized scale, and the total score reflects overall neurological impairment, with higher scores indicating greater severity. The relationship (correlation coefficient) between this score and the NOTCH2NLC GGC repeat number and interruption pattern (defined by long-read sequencing) will be evaluated at baseline and over time.
Time frame: Baseline and at Months 6, 12, 18, and 24
Plan to share: No
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Sichuan Academy of Medical Sciences