Résumé :
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A woman, born in 1962, with personal history of lombar pains and left sciatica in 2007 but without familial history, presented suddenly in 2007 pains in her left calf. CK were elevated (normal X 4). Myalgias with muscle-stiffness progressively extended to both calves and then to the whole lower limbs, with spontaneous muscle contractions.Clinical examination found marked calf hypertrophy, impossible squatting, difficulties when walking on heels and on tiptoes because of pains, no proximal weakness but distal weakness of left lower limb (muscles of calves and peroneus). Tendon reflexes were normal. A 30_ left Lasegue, an hypoesthesia in the left leg were present. No percussion-induced muscular contractions was observed. MRI showed an hyper signal T1-T2 of internal gastrocnemius (fat infiltration). Spine MRI was normal. Cardiac and respiratory functions were normal. Muscle biopsy of left gastrocnemius showed dystrophic changes. Immunohistochemical reactions for all the studied antibodies were normal (dystrophin, sarcoglycans, dystroglycans, dysferlin, caveolin-3, laminins, desmin, myotilin, aBcrystallin, telethonin). Genetic analyses excluded a mutation in dysferlin gene and found an heterozygote mutation in CAV3 gene, in exon 2 : c.216C>G (p.Cyst72Trp). This patient presents as a late LGMD 1C, but the normal reactivity of caveolin-3 in muscle biopsy is very unusual. In previous reports (Leiden Open Variation Database), the CAV3 gene variant found in our patient has been reported to be pathogenic or not (hypomorphe gene).Further studies on the family and on muscle tissue (RNA) are needed to answer the questions asked by this case.
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