Tibial muscular dystrophy, tardive, is a dominantly inherited mild degenerative disorder of anterior tibial muscles. The mutated gene at chromosome 2q31 encodes titin, a giant skeletal muscle protein. Mutations in TTN can also cause: Cardiomyopathy, dilated, 1G (OMIM#604145) Cardiomyopathy, familial hypertrophic, 9 (OMIM#613765) Muscular dystrophy, limb-girdle, type 2J (OMIM#608807) Myopathy, early-onset, with fatal cardiomyopathy (OMIM#611705) Myopathy, proximal, with early respiratory muscle involvement(OMIM# 603689) The clinical disease has a late onset during adulthood, usually after 35 years of age. Reduced ankle dorsiflexion is the main symptom causing mild difficulties of walking. Proximal muscles and upper extremities are not affected. Symptoms rarely progress, and subjective suffering of TMD patients is limited. Affected muscles have nonspecific dystrophic changes with occasional vacuolar degeneration. Electromyography shows myopathic changes in the anterior tibial muscle. Rare homozygous patients present with severe disease, Muscular dystrophy, limb-girdle, type 2J. Clinical diagnosis of TMD is based on CT or MRI studies which demonstrate the muscle dystrophy restricted to anterior tibial muscle. Molecular diagnosis to identify the founder mutation in the titin gene is available.