a fatal degenerative disease involving the corticobulbar, corticospinal, and spinal motor neurons, manifested by progressive weakness and wasting of muscles innervated by the affected neurons; fasciculations and cramps commonly occur. The disorder is 90-95% sporadic in nature (although a number of cases are inherited as an autosomal dominant trait [MIM*105400]), affects adults (typically, older adults), and usually is fatal within 2-5 years of onset. It is in the most common subgroup of motor neuron diseases, and the only one manifested by a combination of upper and lower abnormalities. Variants include: progressive bulbar palsy, in which isolated or predominant lower brainstem motor involvement occurs; primary lateral sclerosis, in which only upper motor neuron abnormalities are seen; and progressive spinal muscle atrophy, in which only lower motor neuron dysfunction is noted.Henry Louis Gehrig. SYN: Aran-Duchenne disease, Charcot disease, Duchenne-Aran disease, Lou Gehrig disease, motor neuron disease (1), progressive muscular atrophy, progressive spinal amyotrophy.