methylmalonic acidemia cblB type

A methylmalonic acidemia characterized by autosomal recessive inheritance, defects in the synthesis of AdoCbl, vitamin B12 therapy responsiveness and that has_material_basis_in homozygous or compound heterozygous mutation in the MMAB gene on chromosome 12q24.

Signs and symptoms

• Decreased methylmalonyl-CoA mutase activity
• Hypotonia
• Elevated circulating propionylcarnitine concentration
• Hyperammonemia
• Hypoglycemia
• Methylmalonic acidemia
• Dilated cardiomyopathy
• Delayed gross motor development
• Persistent head lag
• Elevated circulating methylmalonylcarnitine concentration

Also known as: methylmalonic aciduria cblB type; methylmalonic aciduria, vitamin B12-responsive, due to defect in synthesis of adenosylcobalamin, cblB complementation type