Distal Muscular Dystrophy is a type of muscular dystrophy that affects the muscles of the extremities, the hands, feet, lower arms, or lower legs. The cause of this dystrophy is very hard to determine because it can be a mutation in any of at least eight genes and not all are known yet. These mutations can be inherited from one parent, autosomal dominant, or from both parents, autosomal dominant. Along with being able to inherit the mutated gene, distal muscular dystrophy has slow progress therefore the patient may not know that they have it until they are in their late 40’s or 50’s. There are eight known types of distal muscular dystrophy. They are Welander’s distal myopathy, Finnish (tibial) distal myopathy, Miyoshi distal myopathy, Nonaka distal myopathy, Gowers-Laing distal myopathy, Hereditary inclusion-body myositis type 1, Distal myopathy with vocal cord and pharyngeal weakness, and ZASP-related myopathy. All of these affect different regions of the extremities and can show up as early as 5 years of age to as late as 50 years old. Doctors are still trying to determine what causes these mutations along with effective treatments.
^Hackman P, Sarparanta J, Lehtinen S, Vihola A, Evilä A, Jonson PH, Luque H, Kere J, Screen M, Chinnery PF, Åhlberg G, Edsröm L & Udd B (January 2013). "Welander Distal Myopathy Is Caused by a Mutation in the RNA-Binding Protein TIA1". Annals of Neurology73 (4): 500–509. doi:10.1002/ana.2383. PMID23401021.
^von Tell D, Bruder CE, Anderson LV, Anvret M, Ahlberg G (August 2003). "Refined mapping of the Welander distal myopathy region on chromosome 2p13 positions the new candidate region telomeric of the DYSF locus". Neurogenetics4 (4): 173–7. doi:10.1007/s10048-003-0154-z. PMID12836053.