Snapshot An infant is brought to the pediatrician by his mother due pooling of saliva, a poor suck, and an inability to sit unsupported. The mother reports that the infant’s weakness has progressively worsened ever since birth. Examination is significant for tongue fasciculations and absent deep tendon reflexes. Bell-shaped deformity of the chest is appreciated. Molecular genetic testing for the SMN1 gene is ordered. Introduction WerdnigHoffman Also known as infantile spinal muscle atrophy (SMA type 1) login to view 7 more bullets SMN protein login to view 1 more bullet Epidemiology login to view 3 more bullets Presentation Symptoms login to view 6 more bullets Physical exam login to view 4 more bullets Evaluation Molecular genetic testing login to view 1 more bullet Electromyography (EMG) login to view 1 more bullet Muscle biopsy Differential Congenital myasthenia syndromes Congenital myopathy Treatment Supportive ensure nutritional support and respiratory assistance manage weakness Prognosis, Prevention, and Complications 95% death by 18 months of age and 100% by four years of age Development of kyphosis and scoliosis Weakened pulmonary muscles login to view 1 more bullet Malnutrition login to view 1 more bullet Immobility login to view 1 more bullet