Clinical, phenotypic and genetic landscape of case reports with genetically proven inherited disorders of vitamin B12 metabolism: A meta-analysis

source extracted confidence: high 2026-04-09
#humans #methylmalonic-acid #muscle-hypotonia #vitamin-b-12 #vitamin-b-12-deficiency

Clinical, phenotypic and genetic landscape of case reports with genetically proven inherited disorders of vitamin B12 metabolism: A meta-analysis

Wiedemann et al., 2022 | Cell Rep Med | Meta Analysis

Citation

Wiedemann Arnaud, Oussalah Abderrahim, ... Guéant Jean-Louis. Clinical, phenotypic and genetic landscape of case reports with genetically proven inherited disorders of vitamin B12 metabolism: A meta-analysis. Cell Rep Med. 2022-Jul-19;3(7):100670. doi:10.1016/j.xcrm.2022.100670

Abstract

Inherited disorders of B12 metabolism produce a broad spectrum of manifestations, with limited knowledge of the influence of age and the function of related genes. We report a meta-analysis on 824 patients with a genetically proven diagnosis of an inherited disorder of vitamin B12 metabolism. Gene clusters and age categories are associated with patients' manifestations. The "cytoplasmic transport" cluster is associated with neurological and ophthalmological manifestations, the "mitochondrion" cluster with hypotonia, acute metabolic decompensation, and death, and the "B12 availability" and "remethylation" clusters with anemia and cytopenia. Hypotonia, EEG abnormalities, nystagmus, and strabismus are predominant in the younger patients, while neurological manifestations, such as walking difficulties, peripheral neuropathy, pyramidal syndrome, cerebral atrophy, psychiatric disorders, and thromboembolic manifestations, are predominant in the older patients. These results should prompt systematic checking of markers of vitamin B12 status, including homocysteine and methylmalonic acid, when usual causes of these manifestations are discarded in adult patients.

Key Findings

These results should prompt systematic checking of markers of vitamin B12 status, including homocysteine and methylmalonic acid, when usual causes of these manifestations are discarded in adult patients.

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population adult patients
Sample Size 824
Age Range See abstract
Condition See abstract

MeSH Terms

  • Humans
  • Methylmalonic Acid
  • Muscle Hypotonia
  • Vitamin B 12
  • Vitamin B 12 Deficiency
  • Vitamins

Evidence Classification

  • Level: Meta Analysis
  • Publication Types: Case Reports, Journal Article, Meta-Analysis, Research Support, Non-U.S. Gov't
  • Vertical: vitamin-b12

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09