Which clinical history findings are characteristic of autosomal-recessive limb-girdle muscular dystrophy 2B (LGMD2B)?

Updated: Aug 15, 2019
  • Author: Monica Saini, MD, MBBS, MRCP(UK); Chief Editor: Nicholas Lorenzo, MD, MHA, CPE  more...
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Answer

LGMD2B (dysferlinopathy; LGMDR22 Dysferlin; 2p13)

LGMD2B is also a common cause of autosomal recessive LGMD, accounting for about 20% of cases in the Brazilian population. However, in some populations (eg, Cajun, Arcadian groups), it accounts for about 40% of cases.

Several phenotypes can occur: Miyoshi myopathy, anterior tibial myopathy, LGMD, and an axial myopathy. A study from France showed 25% with Miyoshi myopathy, 25% with LGMD, and 35% with a combination. [12] Different phenotypes can occur in the same family.

With each phenotype, presentation usually occurs at 15–35 years, but it can be as early as 10 years. There are also rare cases of late presentation after age 70 years.

In the limb-girdle presentation, pelvic and femoral muscles are affected first, with the proximal portions of the arms becoming weak later.

With Miyoshi myopathy, the presentation includes gastrocnemius weakness and difficulty with toe walking. The forearm muscles are weak and atrophic, with sparing of intrinsic hand muscles. As the disease progresses, these 2 modes of presentation usually become indistinguishable.

The most common phenotype (35% of patients) has a mixed picture, with both proximal and distal weakness. Asymmetry may be present. The patient's gait is unique, with a waddling component combined with inability to raise his or her heels off the ground.

A few families have been reported with an anterior tibial myopathy. [13] Progressive weakness involves wrist and finger flexor weakness and biceps. Rare cases present with paraspinal (axial) myopathy. [14]

Interestingly, up to 50% of patients diagnosed with dysferlinopathy report a high degree of physical activity and good muscle prowess before the onset of symptoms. [15]

The disease slowly progresses, and patients are usually confined to a wheelchair 10–30 years after the onset of weakness.

Rare cases present with distal leg pain or swelling with or without weakness or with asymptomatic hyperCKemia.

Misdiagnosis as polymyositis can occur since inflammation can be present on muscle biopsy.


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