Methylmalonic acidemia involving high cervical spinal cord leading to respiratory failure: a case report / 中国综合临床

ABSTRACT

Late onset methylmalonic acidemia (MMA) is a rare genetic metabolic disease.This case is a 46 year old adult patient with MMA complicated with hyperhomocysteinemia.It starts with progressive limb weakness and mental abnormality, and has dysuria and respiratory failure.Neurological examination showed decreased muscle strength of limbs and pyramidal tract sign.The levels of blood homocysteine and urinary methylmalonic acid increased significantly.Head, neck, thoracolumbar magnetic resonance imaging showed abnormal signals in the spinal cord from the level of foramen magnum to the level of lumbar 1 vertebral body.Two heterozygous variants of mmachc were found by gene detection: c: 609G>A, c: 349G>A, consistent with cobalamin C deficiency.Treat with L-carnitine, vitamin B12 and betaine.The patients′ mental symptoms, limb muscle strength and respiratory failure were improved, and the level of blood homocysteine also decreased significantly.