[Molybdenum cofactor deficiency caused by MOCS1 gene mutation: a case report]

Area of Science:

• Biochemistry
• Genetics
• Neurology

Background:

• Molybdenum cofactor deficiency (MocoD) is a rare inherited metabolic disorder.
• It affects enzymes crucial for various metabolic pathways, leading to severe health issues.
• MocoD type A is caused by mutations in the MOCS1 gene.

Observation:

• A 1-month-old boy exhibited left hand tremor, microcephaly, distinctive facial features, and severe global developmental delay.
• Cranial MRI revealed encephalomalacia, atrophy, and cystic changes.
• Blood tests indicated reduced serum uric acid levels.

Findings:

• Whole-exome sequencing identified a homozygous c.217C > T (p.R73W) mutation in the MOCS1 gene.
• This mutation, inherited from his parents, was classified as "possibly pathogenic".
• The clinical presentation and genetic findings confirmed the diagnosis of Molybdenum Cofactor Deficiency type A.

Implications:

• This case represents the first documented instance of Molybdenum Cofactor Deficiency type A in China.
• Highlights the importance of genetic testing in diagnosing rare metabolic disorders.
• Contributes to the understanding of MOCS1 gene mutations and their phenotypic manifestations.