Английская Википедия:Distal myopathy

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Шаблон:Infobox medical condition (new)

Distal myopathy is a group of rare genetic disorders that cause muscle damage and weakness, predominantly in the hands and/or feet. Mutation of many different genes can be causative. Many types involve dysferlin.[1]

Signs and symptoms

All of the different types affect different regions of the extremities and can show up as early as 5 years of age to as late as 50 years old. Distal myopathy has slow progress therefore the patient may not know that they have it until they are in their late 40s or 50s.Шаблон:Citation needed

Miyoshi myopathy affects the posterior muscles of the lower leg, more so than the anterior muscles of the lower leg.[2][3]

Cause

Файл:4ihb pdb.png
DYSF

The cause of this myopathy 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 recessive. There are eight known types of distal myopathy.Шаблон:Citation needed

Types

Classic distal muscular dystrophies
Type Eponym Inheritance OMIM Gene Locus Gene also implicated in:
Late adult-onset type 1[4] Welander AD[5] Шаблон:OMIM TIA1[6] 2p13[7]
Late adult-onset type 2a[5] - Finnish (tibial) Udd AD[5] Шаблон:OMIM TTN[5] 2q31.2
Late adult-onset type 2b[5] Markesbery–Griggs AD[8] ZASP[5] 10q23.2
Early adult-onset type 1[4] Nonaka AR[5] Шаблон:OMIM GNE[5] 9p13.3
Early adult-onset type 2[4] Miyoshi AR[5] Шаблон:OMIM DYSF[5] 2p13.3-p13.1 limb-girdle muscular dystrophy type 2B.[9]
Distal myopathy with anterior tibial onset (DMAT)[10][11] Шаблон:OMIM DMAT can be considered a variant of Miyoshi.
Early adult-onset type 3[4] Laing (Gower) AD[5] Шаблон:OMIM MYH7[5] 14q11.2
AD = autosomal dominant; AR = autosomal recessive
Myofibrillar myopathies classifiable as distal myopathy
Type Eponym Inheritance OMIM Gene Locus Gene also implicated in:
Desmin — adult onset (MFM1)[5]

Hereditary inclusion-body myositis type 1[5]

AD
αB-crystallin — early - mid adult (MFM2)[5] AD
ZASP— late adult (MFM4)[5] AD
Scapuloperoneal[5] AD
MFM = myofibrillary myopathy; AD = autosomal dominant; AR = autosomal recessive
Other distal muscular dystrophies
Type Eponym Inheritance OMIM Gene Locus Gene also implicated in:
Distal myopathy with vocal cord and pharyngeal weakness[4] AD[5] Шаблон:OMIM MATR3[5] 5q31[5] Amyotrophic lateral sclerosis 21 (ALS21). One study suggests that all cases are ALS, justifying reclassification.[12]

Diagnosis

In terms of diagnosis, Vocal cord and pharyngeal distal myopathy should be assessed via serum CK levels, as well as muscle biopsy of the individual suspected of being afflicted with this condition[13]

Management

As of 2011, no disease modifying treatments are known.[8] Foot drop can be managed with ankle-foot orthoses or surgical tendon transfer,[8] in which the tibialis posterior muscle is repurposed to function as a tibialis anterior muscle. In select types of distal myopathy, evaluation of the heart may be indicated.[8] Scoliosis and contractures can be surgically managed.[8]

References

Шаблон:Reflist

Further reading

External links

Шаблон:Medical resources

Шаблон:Muscular Dystrophy Шаблон:Diseases of myoneural junction and muscle Шаблон:Other cell membrane protein disorders