A: The variant NC_000019.10:g.48970984T>C in gene GYS1 is classified as 'Uncertain_significance' for Glycogen_storage_disease_due_to_muscle_and_heart_glycogen_synthase_deficiency. Molecular consequence: SO:0001583: missense_variant,SO:0001619: non-coding_transcript_variant. Variant type: single_nucleotide_variant. Disease database links: MONDO:MONDO:0012693,MedGen:C1969054,OMIM:611556,Orphanet:137625. Review status: criteria provided, single submitter.