Late-onset cblC defect: clinical, biochemical and molecular analysis
Si Ding1, Shiying Ling1, Lili Liang1
1Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute of Pediatric Research, Shanghai Jiao Tong University School of Medicine, 1665 KongJiang Road, Shanghai, 200092, China.
Orphanet Journal of Rare Diseases
|September 28, 2023
Summary
Late-onset cblC defect, a common methylmalonic acidemia in China, presents with diverse symptoms leading to delayed diagnosis. Prompt identification and treatment are crucial for improving outcomes in these patients.
Area of Science:
- Biochemistry
- Genetics
- Pediatrics
Background:
- cblC defect is the most common methylmalonic acidemia in China.
- Late-onset forms (>1 year) are frequently misdiagnosed due to varied symptoms.
- This study focuses on Chinese patients with late-onset cblC defect.
Purpose of the Study:
- To describe the clinical characteristics of Chinese patients with late-onset cblC defect.
- To evaluate the long-term outcomes of these patients.
- To identify risk factors for poor prognosis.
Main Methods:
- Retrospective analysis of 85 patients with late-onset cblC defect.
- Summarized and analyzed clinical data, metabolites, molecular diagnosis, treatment, and outcomes.
- Used univariate and multivariate logistic regression to identify risk factors.
Main Results:
- Onset ranged from 2 to 32.8 years, with a median of 8.6 years.
- Neuropsychiatric symptoms were the most common initial presentation (68.2%).
- Delayed diagnosis (median 2 months) and the time from onset to diagnosis were independent risk factors for poor outcomes.
Conclusions:
- Late-onset cblC defect diagnosis is often delayed due to nonspecific symptoms, impacting prognosis.
- Consider cblC defect in unexplained neuropsychiatric, renal, or cardiovascular conditions.
- Prompt treatment is beneficial, and the c.482G>A variant is frequent.
