Pyomyositis is a pyogenic infection of skeletal striated muscle, usually found in tropical areas, often in immunocompromised patients. We report a new observation of a nontropical Enterobacter pyomyositis occurring in an immunocompetent female in Tunisia. A 53-year-old patient presented with acute fever and intense myalgia in the right thigh. On clinical examination she had an altered general condition, a fever at 40°C and an important swelling of the lateral side of the right thigh. In biology, she had an inflammatory syndrome. Blood culture had identified Enterobacter. Muscle magnetic resonance imaging showed diffuse inflammatory involvement of the vastus lateralis muscle of the right quadriceps associated with edematous infiltration of subcutaneous fatty tissues. Diagnosis of pyomyositis was retained. Antibiotic therapy initially probabilistic and then adapted to the antibiogram was initiated with a favorable outcome. Although rare outside the tropics, the potential severity of pyomyositis encourages its better knowledge.

Bethlem myopathy (BM) is a disease that is caused by mutations in the collagen VI genes. It is a mildly progressive disease characterized by proximal muscle weakness and contracture of the fingers, the wrist, the elbow, and the ankle. BM is an autosomal dominant inheritance that is mainly caused by dominant COL6A1, COL6A2, or COL6A3 mutations. However, a few cases of collagen VI mutations with bilateral facial weakness and Beevor\'s sign have also been reported. This study presents a 50-year-old female patient with symptoms of facial weakness beginning in childhood and with the slow progression of the disease with age. At the age of 30 years, the patient presented with asymmetrical proximal muscle weakness, and the neurological examination revealed bilateral facial weakness and a positive Beevor\'s sign. Phosphocreatine kinase was slightly elevated with electromyography showing myopathic changes and magnetic resonance imaging (MRI) of the lower limb muscles showing the muscle MRI associated with collagen VI (COL6)-related myopathy (COL6-RM). The whole-genome sequencing technology identified the heterozygous mutation c.6817-2(IVS27)A>G in the COL6A3 gene, which was in itself a novel mutation. The present study reports yet another case of BM, which is caused by the recessive COL6A3 intron variation, widening the clinical spectrum and genetic heterogeneity of BM.

A 36-year-old woman who presented with upper limb distal weakness since the age of 15 years, with gradual progression to the lower limbs, is reported. Hereditary motor neuropathy was initially suspected based on distal weakness and hyporeflexia; however, whole exome sequencing accidentally revealed a compound heterozygous variant in the GNE gene, and ultrasound revealed increased homogeneous echogenicity in the involved muscles, which is characteristic of myopathic changes. Muscle magnetic resonance imaging revealed fatty infiltration in all limb muscles, sparing the triceps brachii, vastus lateralis and vastus medialis. Muscle biopsy revealed intracytoplasmic rimmed vacuole, supporting the diagnosis of GNE myopathy.

Colchicine is a medication most commonly used in the treatment of gout and familial mediterannean fever. A rare complication of therapy is toxicity causing proximal myopathy and polyneuropathy. Colchicine myopathy has been associated with the coadministration of other medications with colchicine, such as statins or tacrolimus, and is more common in patients with renal impairment. Otherwise, it is unclear which patients are at greatest risk of developing this adverse drug reaction. ABCB1 is important to the metabolism of colchicine, so we speculated that it was possible that colchicine myopathy patients may have a particular genotype that is associated with this side effect. We describe two cases of colchicine myopathy which occurred with co-administration of rosuvastatin. From one case, we present the first published data on muscle MRI in this condition. We additionally present an analysis of four genetic polymorphisms in ABCB1 and transcript levels in muscle tissue, and demonstrate the descriptive finding of reduced ABCB1 transcript levels in the colchicine myopathy patients.

BACKGROUND: Myosin heavy chain 7 related myopathies are rare disorders characterized by a wide phenotypic spectrum and heterogeneous pathological features. In the present study, we performed clinical, morphological, genetic and imaging investigations in three relatives affected by autosomal dominant distal myopathy. Whilst earlier traditional Sanger investigations had pointed to the wrong gene as disease causative, next-generation sequencing allowed us to obtain the definitive molecular genetic diagnosis in the family.
METHODS: The proposita, being found to harbor a novel heterozygous mutation in the RYR1 gene (p.Glu294Lys), was initially diagnosed with core myopathy. Subsequently, consideration of muscle magnetic resonance imaging (MRI) features and extension of family study led this diagnosis to be questioned. Use of next-generation sequencing analysis identified a novel mutation in the MYH7gene (p.Ser1435Pro) that segregated in the affected family members.
CONCLUSIONS: This study identified a novel mutation in MYH7 in a family where the conclusive molecular diagnosis was reached through a complicated path. This case report might raise awareness, among clinicians, of the need to interpret NGS data in combination with muscle MRI patterns so as to facilitate the pinpointing of the main molecular etiology in inherited muscle disorders.