Association of Lupus with Spinal Muscular Atrophy and Suspected Bronchial Cancer

SLE is an autoimmune disease with multiple organ involvement. It may affect musculo-skeletal and nervous systems resulting in muscle weakness and atrophy. Classification criteria for the diagnosis of SLE were defined by the American College of Rheumatology. Spinal muscular atrophy (SMA) is characterised by degeneration of motor neurons of the spinal cord, which also may result in muscle weakness and hypotony. Earlier, the diagnosis was based on electromyography (EMG) and muscle biopsy findings. Electromyography characteristic of the disorder shows features of denervation with spontaneous activity of positive sharp waves, fibrillation, and occasional fasciculations. Motor unit action potential shows high amplitudes and long durations coupled with decreased recruitment. Histopathology of skeletal muscle usually shows atrophic fibres with islands of group hypertrophy, and severe loss of motor neuron in the spinal cord [1,2]. It is caused by homozygous disruption of the survival motor neuron 1 (SMN1) gene in form of deletion, conversion, or mutation. SMN1 is expressed in all tissues, but almost exclusively affects lower motor neurons. SMA divided into four clinical types: severe type I, intermediate type II, mild type III, and adult-onset type IV has been added to include very mild disease. Patients with type IV disease typically have onset of weakness in the second or third decades of life [3-5].