Disease relevance of WDM

• The WDM region overlaps with the linkage region for Miyoshi myopathy and limb-girdle muscular dystrophy 2B [1].
• Welander distal myopathy (WDM) is an autosomal dominant myopathy with late-adult onset characterized by slow progression of distal muscle weakness [1].
• The dysferlin gene, a strong candidate gene responsible for two other distal myopathies in the same region, is located centromeric to PAC3-H52 and can thereby formally be excluded as cause for WDM [2].
• Five patients with inclusion body myositis (IBM), an acquired inflammatory myopathy, and five patients with Welander hereditary distal myopathy (WDM) were compared clinically and with neurophysiological and morphological techniques [3].

High impact information on WDM

• The dysferlin gene responsible for these disorders is considered a primary candidate gene for WDM [1].
• Genetic linkage of Welander distal myopathy to chromosome 2p13 [1].
• The most representative diseases are dominantly inherited Welander distal myopathy and tibial muscular dystrophy, and the recessively inherited distal myopathy with rimmed vacuoles and distal muscular dystrophy (Miyoshi myopathy) [4].
• Haplotype analysis with the five polymorphic markers that make up the common core haplotype, seen in the Swedish patients, revealed that this haplotype is also co-segregating in the Finnish patients and a common ancestry is therefore further supported for patients with Welander distal myopathy [5].
• Welander distal myopathy outside the Swedish population: phenotype and genotype [5].

Biological context of WDM

• A neurogenic component in Welander distal myopathy has been suggested, on the grounds of a sensory dysfunction, neuropathic findings on neurophysiology and muscle biopsy and a decrease of A-delta nerve fibres on sural nerve biopsy [6].

Anatomical context of WDM

• This paper reports on an external-cavity-diode laser (ECDL) employing a fiber Bragg grating, which was newly designed for WDM applications without temperature control [7].
• Seven patients with Welander distal myopathy were subjected to magnetic resonance imaging (MRI) of the lower extremity, and muscle biopsies of the tibialis anterior, soleus and vastus lateralis muscles [8].
• It is concluded that patients with Welander distal myopathy have no signs of dysfunction of the peripheral autonomic nerves [9].

Other interactions of WDM

• Increased staining for spectrin, desmin and Leu-19 has been described in denervated muscle fibres and, thus, the present findings may support earlier findings of a neurogenic component in Welander distal myopathy [10].

Analytical, diagnostic and therapeutic context of WDM

• Autonomically mediated cardiovascular responses were evaluated in 9 patients with Welander distal myopathy and compared to data from an age- and sex-matched control group [9].

References