Glycogenin-1 deficiency and inactivated priming of glycogen synthesis.

• Glycogen, which serves as a major energy reserve in cells, is a large, branched polymer of glucose molecules. We describe a patient who had muscle weakness, associated with the depletion of glycogen in skeletal muscle, and cardiac arrhythmia, associated with the accumulation of abnormal storage material in the heart. The skeletal muscle showed a marked predominance of slow-twitch, oxidative muscle fibers and mitochondrial proliferation. Western blotting showed the presence of unglucosylated glycogenin-1 in the muscle and heart. Sequencing of the glycogenin-1 gene, GYG1, revealed a nonsense mutation in one allele and a missense mutation, Thr83Met, in the other. The missense mutation resulted in inactivation of the autoglucosylation of glycogenin-1 that is necessary for the priming of glycogen synthesis in muscle.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Cell- och molekylärbiologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Cell and Molecular Biology (hsv//eng)

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Neurologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Neurology (hsv//eng)

Nyckelord

Adult

Arrhythmias

Cardiac

etiology

Codon

Nonsense

DNA

Complementary

analysis

Dizziness

etiology

Female

Glucosyltransferases

deficiency

genetics

Glycogen

biosynthesis

Glycoproteins

deficiency

genetics

Humans

Male

Muscle

Skeletal

chemistry

pathology

Mutation

Missense

Pedigree

RNA

Messenger

analysis

Sequence Analysis

DNA

Medical sciences

Publikations- och innehållstyp

ref (ämneskategori)

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