Eight novel mutations in MLC1 from 18 Iranian patients with megalencephalic leukoencephalopathy with subcortical cysts.

Megalencephalic leukoencephalopathy with subcortical cysts (MLC) (MIM #604004) is a rare autosomal recessive neurological disorder characterized by macrocephaly, motor and cognitive decline, ataxia, spasticity and occasional seizures. Magnetic resonance imaging (MRI) shows diffusely abnormal and swollen white matter of the cerebral hemispheres and subcortical cysts in the anterior temporal and frontoparietal region. Mutations in MLC1(22q13.33) and GLIALCAM have been identified in patients with MLC. Mutations in MLC1 account for approximately 75% of the cases. MLC was suspected in eighteen Iranian patients from sixteen families based on positive clinical findings including macrocephaly beginning in the first year, neurocognitive deterioration, seizure or loss of consciousness after minor head trauma. All except two were born to consanguineous parents. Brain MRI images were compatible with MLC and confirmed the diagnosis. Sequencing of entire coding region of MLC1 was performed for seventeen patients and mutations in MLC1 were detected in all of them. Eight novel mutations and seven previously reported mutations were identified. This report shows that MLC is relatively common in Iranian population, as expected for rare diseases with high inbreeding, with a surprisingly high frequency of novel mutations.

Evaluation of one hundred pediatric muscle biopsies during a 2-year period in mofid children and toos hospitals.

OBJECTIVE: Muscle biopsy is a very important diagnostic test in the investigation of a child with suspected neuromuscular disorder. The goal of this study was to review and evaluate pediatric muscle biopsies during a 2-year period with focus on histopathology diagnosis and correlations with other paraclinic studies. MATERIALS & METHODS: We investigated 100 muscle biopsies belonging to patients with clinical impression of neuromuscular disorder. These patients have been visited consecutively by pediatric neurologists during 2010 to 2012. Samples were investigated by standard enzyme histochemical and immunohistochemical techniques. RESULT: Sixty-nine (69%) males and 39 (39%) females with a mean age of 5.7 years were evaluated. Major pathologic diagnoses were Muscular dystrophy (48 cases), Neurogenic atrophy (18 cases), nonspecific myopathic atrophy (12cases), congenital myopathy (6 cases), storage myopathies (4 cases) and in 6 cases there was no specific histochemical pathologic finding. EMG was abnormal in 79 cases. Degree of correlation between EMG and biopsy result was significant in children ≥ 2 years of age. CONCLUSION: This study confirms the high diagnostic yields of muscle biopsy especially only if standard and new techniques such as enzyme study and immunohistochemistry are implemented. Also, we report 11 cases of Merosin negative congenital muscular dystrophy. This is the largest documented case series of Merosin deficient congenital muscular dystrophy reported from Iran.