biostudies-literatureBader IAustrian Science Fund FWF279https://www.ebi.ac.uk/biostudies/studies/S-EPMC9295345biostudies-literatureUnknown17(1)<h4>Background</h4>Alterations in the MYH7 gene can cause cardiac and skeletal myopathies. MYH7-related skeletal myopathies are extremely rare, and the vast majority of causal variants in the MYH7 gene are predicted to alter the rod domain of the of ß-cardiac myosin molecule, resulting in distal muscle weakness as the predominant manifestation. Here we describe two unrelated patients harboring an in-frame deletion in the MYH7 gene that is predicted to result in deletion of a single amino acid (p.Glu500del) in the head domain of ß-cardiac myosin. Both patients display an unusual skeletal myopathy phenotype with congenital axial stiffness and muscular hypertonus, but no cardiac involvement.<h4>Results</h4>Clinical data, MRI results and histopathological data were collected retrospectively inOrphanet journal of rare diseasesA recurrent single-amino acid deletion (p.Glu500del) in the head domain of ß-cardiac myosin in two unrelated boys presenting with polyhydramnios, congenital axial stiffness and skeletal myopathy.PMC9295345I 4695Landauer FRauscher CSperl WMueller-Felber WFreilinger MBader ISchmidt WMMayr JABittner REWaldmuller SfalseA recurrent single-amino acid deletion (p.Glu500del) in the head domain of ß-cardiac myosin in two unrelated boys presenting with polyhydramnios, congenital axial stiffness and skeletal myopathy.<h4>Background</h4>Alterations in the MYH7 gene can cause cardiac and skeletal myopathies. MYH7-related skeletal myopathies are extremely rare, and the vast majority of causal variants in the MYH7 gene are predicted to alter the rod domain of the of ß-cardiac myosin molecule, resulting in distal muscle weakness as the predominant manifestation. Here we describe two unrelated patients harboring an in-frame deletion in the MYH7 gene that is predicted to result in deletion of a single amino acid (p.Glu500del) in the head domain of ß-cardiac myosin. Both patients display an unusual skeletal myopathy phenotype with congenital axial stiffness and muscular hypertonus, but no cardiac involvement.<h4>Results</h4>Clinical data, MRI results and histopathological data were collected retrospectively in2022-01-01T00:00:00Z2022 Jul2026-07-14T21:37:49.123Z2026-06-26T03:07:49.975ZS-EPMC92953453585431510.1186/s13023-022-02421-7