Autosomal dominantly inherited myopathy likely caused by the TNNT1 variant p.(Asp65Ala)
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- Autor/in:
- Erscheinungsjahr:
- 2022
- Medientyp:
- Text
- Beschreibung:
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Nemaline myopathies (NEMs) are genetically and clinically heterogenous. Biallelic or monoallelic variants in TNNT1, encoding slow skeletal troponin T1 (TnT1), cause NEM. We report a 2-year-old patient and his mother carrying the heterozygous TNNT1 variant c.194A>C/p.(Asp65Ala) that occurred de novo in the mother. Both had muscle hypotrophy and muscle weakness. Muscle pathology in the proband's mother revealed slow twitch type 1 fiber hypotrophy and fast twitch type 2 fiber hypertrophy that was confirmed by a reduced ratio of slow skeletal myosin to fast skeletal myosin type 2a. Reverse transcription polymerase chain reaction and immunoblotting data demonstrated increased levels of high-molecular-weight TnT1 isoforms in skeletal muscle of the proband's mother that were also observed in some controls. In an overexpression system, complex formation of TnT1-D65A with tropomyosin 3 (TPM3) was enhanced. The previously reported TnT1-E104V and TnT1-L96P mutants showed reduced or no co-immunoprecipitation with TPM3. Our studies support pathogenicity of the TNNT1 p.(Asp65Ala) variant.
- Lizenz:
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- info:eu-repo/semantics/openAccess
- Quellsystem:
- Forschungsinformationssystem des UKE
Interne Metadaten
- Quelldatensatz
- oai:pure.atira.dk:publications/c4379514-b012-4e64-b273-eb205a60c38f