Spinal muscular atrophy (SMA) is an inherited disease of anterior horn cells affecting children and adults. Patients experience progressive loss of muscle strength. No curative treatment exists, and management focuses mainly on multi-disciplinary palliative care.

Two patients (1M, ages 4 and 5 years) with SMA type II gave the same past medical history. While breast fed for the first several months of life, these children appeared normal. The onset of their muscle weakness began approximately two weeks after their first exposure to a cow-milk based infant formula. Once diagnosed, (+ SMN deletion of chromosome 5) to insure adequate nutrition, both had received a daily cow-milk formula supplement. Both had other chronic symptoms of abdominal pain, retching, anorexia, early satiety, and diarrhea associated with the ingestion of these milk-based formulas. Their feedings were changed from a cow-milk based formula (Pediasure(R)) to an amino-acid based formula (Neocate-1-plus(R)), and their solid food diets were modified to completely exclude all sources of cow milk protein for a 12 month period. The total calories delivered each day were unchanged, but they were completely free of any source of cow-milk protein.

After six months on the modified diet, these patients experienced marked improvements in muscle strength and range-of-motion of the upper and lower extremities. Both have developed independent head control including head-up position against gravity. Both can roll from front to back when supine, and have developed digital fine motor skills to include self-feeding. Their endurance, appetite, abdominal pain and diarrhea have improved. Both showed catch-up growth with increases in height, and chest and extremity circumferences, without an increase in their total delivered calories.

These observations suggest a possible relationship between the ingestion of cow-milk protein and the chronic muscle weakness of children with SMA. Further study of these observations are warranted