Hereditary motor and sensory neuropathy with proximal dominance (HMSN-P) is an

autosomal dominant In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and t ...

neurodegenerative disorder that is defined by extensive involuntary and spontaneous muscle contractions,

asthenia Weakness is a symptom of a number of different conditions. The causes are many and can be divided into conditions that have true or perceived muscle weakness. True muscle weakness is a primary symptom of a variety of skeletal muscle diseases, i ...

, and atrophy with

distal Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...

sensory involvement following. The disease starts presenting typically in the 40s and is succeeded by a slow and continuous onslaught. Muscle

spasm A spasm is a sudden involuntary contraction of a muscle, a group of muscles, or a hollow organ such as the bladder. A spasmodic muscle contraction may be caused by many medical conditions, including dystonia. Most commonly, it is a muscle c ...

s and muscle contractions large in number are noted, especially in the earliest stages. The presentation of HMSN-P is quite similar to

amyotrophic lateral sclerosis Amyotrophic lateral sclerosis (ALS), also known as motor neuron disease (MND) or Lou Gehrig's disease, is a neurodegenerative disease that results in the progressive loss of motor neurons that control voluntary muscles. ALS is the most comm ...

and has common neuropathological findings.

Sensory loss Many types of sense loss occur due to a dysfunctional sensation process, whether it be ineffective receptors, nerve damage, or cerebral impairment. Unlike agnosia, these impairments are due to damages prior to the perception process. Vision loss ...

happens as the disease progresses, but the amount of sensation lost varies from case to case. There have been other symptoms of HMSN-P reported such as urinary disturbances and a dry cough. Two large families in Japan have been identified with the disease locus to chromosome 3q. From descendants of Japan, HMSN-P was brought to Brazil, from there it is a pretty isolated disease. Through clinical studies, researchers identified that TFG mutations on chromosome 3q13.2 causes HMSN-P. "The presence of TFG/ubiquitin- and/or TDP-43-immunopositive cytoplasmic inclusions in motor neurons and cytosolic aggregation composed of TDP-43 in cultured cells expressing mutant TFG indicate a novel pathway of motor neuron death" __NOTOC__

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{{Medical resources , ICD10 = G60.0 , ICD9 = , ICDO = , OMIM = 604484 , DiseasesDB = , MedlinePlus = , eMedicineSubj = , eMedicineTopic = , MeSH = C535717 , GeneReviewsNBK = , GeneReviewsName = , Orphanet = 90117 Neurodegenerative disorders

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