Congenital myasthenic syndrome due to DOK7 mutation in a cohort of patients with 'unexplained' limb-girdle muscular weakness.

Congenital myasthenic syndromes (CMS) associated with pathogenic variants in the DOK7 gene (DOK7-CMS) have phenotypic overlap with other neuromuscular disorders associated with limb-girdle muscular weakness (LGMW). Genetic analysis of the most common mutation (c.1124_1127dupTGCC) in DOK7 was performed in 34 patients with "unexplained" LGMW associated with non-specific changes in muscle biopsy. Of the 34 patients, one patient showed the DOK7 c.1124_1127dupTGCC variant in homozygousity. Our study estimates the minimum prevalence of undiagnosed DOK7-CMS to be 2.9% in southern Brazilian patients from our centre. Our data confirm that clinicians should look for DOK7-CMS patients when the clinical manifestation is an 'unexplained' LGMW, mainly if associated with non-specific changes in muscle biopsy.

Congenital Myasthenic Syndrome due to DOK7 mutations in a family from Chile.

Congenital myasthenic syndromes (CMS) are neuromuscular transmission disorders caused by mutations in genes encoding neuromuscular junction proteins. A 61-year-old female and her older sister showed bilateral ptosis, facial and proximal limb weakness, and scoliosis since childhood. Another female sibling had milder signs, while other family members were asymptomatic. Facial nerve repetitive stimulation in the proband showed decrement of muscle responses. Single fiber EMG revealed increased jitter and blocking. Muscle biopsy showed type 2-fiber atrophy, without tubular aggregates. Mutational analysis in the three affected siblings revealed two compound heterozygous mutations in DOK7: c.1457delC, that predicts p.Pro486Argfs*13 and truncates the protein C-terminal domain, and c.473G>A, that predicts p.Arg158Gln and disruption of the dok7-MuSK interaction in the phosphotyrosine binding (PTB) domain. Unaffected family members carried only one or neither mutation. Discussion: Two of the affected sisters showed marked improvement with salbutamol treatment, which illustrates the benefits of a correct diagnosis and treatment of DOK7-CMS.

Protein microarray for complex apoptosis monitoring of dysplastic oral keratinocytes in experimental photodynamic therapy

BACKGROUND: Photodynamic therapy is an alternative treatment of muco-cutaneous tumors that uses a light source able to photoactivate a chemical compound that acts as a photosensitizer. The phthalocyanines append to a wide chemical class that encompasses a large range of compounds; out of them aluminium-substituted disulphonated phthalocyanine possesses a good photosensitizing potential. RESULTS: The destructive effects of PDT with aluminium-substituted disulphonated phthalocyanine are achieved by induction of apoptosis in tumoral cells as assessed by flow cytometry analysis. Using protein microarray we evaluate the possible molecular pathways by which photodynamic therapy activates apoptosis in dysplastic oral keratinocytes cells, leading to the tumoral cells destruction. Among assessed analytes, Bcl-2, P70S6K kinase, Raf-1 and Bad proteins represent the apoptosis related biomolecules that showed expression variations with the greatest amplitude. CONCLUSIONS: Up to date, the intimate molecular apoptotic mechanisms activated by photodynamic therapy with this type of phthalocyanine in dysplastic human oral keratinocytes are not completely elucidated. With protein microarray as high-throughput proteomic approach a better understanding of the manner in which photodynamic therapy leads to tumoral cell destruction can be obtained, by depicting apoptotic molecules that can be potentially triggered in future anti-tumoral therapies.

Salbutamol therapy in congenital myasthenic syndrome due to DOK7 mutation.

INTRODUCTION: Salbutamol is a selective B2-adrenergic agonist, which has previously been described to be associated with partial improvement of myasthenia gravis and congenital myasthenic syndromes (CMS). In this study, we analyzed the effect of salbutamol in five patients with Dok-7 CMS. METHODS: We studied 5 patients (2 male and 3 female), with a mean age of 27±11.06 years, who harbored c.1124_1127dupTGCC, p.G64R and/or p.S45L mutations in DOK7 gene. Salbutamol was given at a dose of 2mg three times daily (6 mg/day) to all patients. The response was assessed by QMG score at baseline, 3, 6, 9 and 12 months; ADL-MG score and 6 minute walk test at baseline and after 12 months during follow-up clinic visits. Side effect profile of salbutamol was also evaluated. RESULTS: We noted an increasingly positive response as measured by the QMG score after 3 months of salbutamol treatment. Improvement in specific subcomponents of the QMG score such as leg outstretched in 45° supine was most marked. In ADL-MG scores and 6 minute walk test, comparison between baseline and after 12 months revealed a clear beneficial response. Salbutamol was well tolerated in all patients. CONCLUSIONS: Salbutamol is an effective treatment in Dok-7 CMS. This study provides class IV evidence that salbutamol given at a dose 6 mg/day improves function as measured by the QMG score, ADL-MG score and 6 minute walk test.