Eosinophilic Oesophagitis in Spinal Muscular Atrophy

SMN protein and SMA

Though rare, spinal muscular atrophy (SMA) does sometimes co-occur with other rare conditions. Both SMA type 2 and eosinophilic oesophagitis (EoE) occur in approximately 0.16-4 per 10,000 people,1–4 but the conditions have also been simultaneously observed in individual patients. A recent publication even reported on two cases of SMA type 2 with EOE that concurrently presented in the same small geographical location.5

Eosinophilic Oesophagitis

EoE is a chronic immune/antigen-mediated oesophageal disease that involves oesophageal dysfunction and occurs 3 times more often in men than in women.5,6 The main symptoms associated with EoE in children include feeding difficulties, abdominal pain, and vomiting. In adolescents and adults, symptoms include dysphagia and food impaction. The antigens mediating the disease are primarily food-based antigens. 

The symptoms of EoE were once thought to be a manifestation of gastroesophageal reflux disease (GERD), but in the 1990s, researchers realized that neither the symptoms nor the histological characteristics were affected by acid suppression or anti-reflux surgery and so suggested that the condition was actually distinct from GERD.7 EoE is also associated with a number of other conditions, including celiac disease, Crohn’s disease, and connective tissue diseases.8–10 

Given its growing prevalence, researchers have suggested that EoE may result from environmental factors. Specifically, they believe that alterations to the immune system may predispose people to EoE, as risk factors for the disease include: cesarean section birth, premature delivery, lack of breastmilk, antibiotic exposure, and living in areas where population density is low.11,12

SMA Type 2 and Eosinophilic Oesophagitis

Two recently described cases of SMA type 2 with EoE were treated simultaneously in the same geographic area of the United Kingdom (UK). One case involved a 3 year old boy who was experiencing aversion to food, pain while eating, and resultant inadequate weight gain.5 A gastroscopy (OGD) examination showed no signs of EoE until it was re-performed when the patient was 5 years old. Treatment with a daily dose of 10 milligrams (mg) of esomeprazole and twice daily dose of 500 mg of Budesonide nebules mixed with Candorel sweetener eliminated symptoms of EoE by the time the patient was 6. 

The other case of SMA type 2 with EoE in the UK involved a 7.5 year old girl who also experienced poor weight gain, as well as persistent gastro-oesophageal reflux.5 Because she did not initially have enough eosinophils to meet the criteria for an EoE diagnosis and because her oesophagus appeared normal macroscopically, the patient was not diagnosed with EoE until she was 14. Unlike the other case, this patient did not seem to respond to Budenoside and so discontinued its use. She did, however, experience the relief of some symptoms while taking antihistamines. 

Identifying EoE in SMA patients can be difficult, given that oesophageal reflux is a common gastrointestinal (GI) symptom encountered by SMA patients.5,13 Indeed, GI symptoms are associated with scoliosis, a common condition in SMA.14 Though the data compiled so far do not suggest a concomitant association between SMA and EoE, researchers suggest that patients with SMA who present with oral aversion, discomfort, and gastro-oesophageal reflux should be examined for EoE, particularly because EoE is treatable.5 Identifying EoE when it occurs thus offers an opportunity to improve SMA patients’ symptoms and quality of life.


1. Liacouras CA, Furuta GT, Hirano I, et al. Eosinophilic esophagitis: updated consensus recommendations for children and adults. J Allergy Clin Immunol. 2011;128(1):2-3. doi:10.1016/j.jaci.2011.02.040

2. Noel RJ, Putnam PE, Rothenberg ME. Eosinophilic esophagitis. N Engl J Med. 2004;351(9):940-941. doi:10.1056/NEJM200408263510924

3. Cherian S, Smith NM, Forbes DA. Rapidly increasing prevalence of eosinophilic oesophagitis in Western Australia. Arch Dis Child. 2006;91(12):1000-1004. doi:10.1136/adc.2006.100974

4. Ogino S, Wilson RB, Gold B. New insights on the evolution of the SMN1 and SMN2 region: simulation and meta-analysis for allele and haplotype frequency calculations. Eur J Hum Genet. 2004;12(12):1015-1023. doi:10.1038/sj.ejhg.5201288

5. Fuller HR, Shorrock HK, Gillingwater TH, et al. Two Cases of Spinal Muscular Atrophy Type II with Eosinophilic Oesophagitis. J Neuromuscul Dis. 2017;4(4):357-362. doi:10.3233/JND-170260

6. Kapel RC, Miller JK, Torres C, Aksoy S, Lash R, Katzka DA. Eosinophilic esophagitis: a prevalent disease in the United States that affects all age groups. Gastroenterology. 2008;134(5):1316-1321. doi:10.1053/j.gastro.2008.02.016

7. Furuta GT, Katzka DA. Eosinophilic Esophagitis. N Engl J Med. 2015;373(17):1640-1648. doi:10.1056/NEJMra1502863

8. Abonia JP, Wen T, Stucke EM, et al. High prevalence of eosinophilic esophagitis in patients with inherited connective tissue disorders. J Allergy Clin Immunol. 2013;132(2):378-386. doi:10.1016/j.jaci.2013.02.030

9. Mulder DJ, Hookey LC, Hurlbut DJ, Justinich CJ. Impact of Crohn disease on eosinophilic esophagitis: evidence for an altered T(H)1-T(H)2 immune response. J Pediatr Gastroenterol Nutr. 2011;53(2):213-215. doi:10.1097/MPG.0b013e318213bf79

10. Jensen ET, Eluri S, Lebwohl B, Genta RM, Dellon ES. Increased Risk of Esophageal Eosinophilia and Eosinophilic Esophagitis in Patients With Active Celiac Disease on Biopsy. Clin Gastroenterol Hepatol. 2015;13(8):1426-1431. doi:10.1016/j.cgh.2015.02.018

11. Jensen ET, Hoffman K, Shaheen NJ, Genta RM, Dellon ES. Esophageal eosinophilia is increased in rural areas with low population density:  results from a national pathology database. Am J Gastroenterol. 2014;109(5):668-675. doi:10.1038/ajg.2014.47

12. Jensen ET, Kappelman MD, Kim HP, Ringel-Kulka T, Dellon ES. Early life exposures as risk factors for pediatric eosinophilic esophagitis. J Pediatr Gastroenterol Nutr. 2013;57(1):67-71. doi:10.1097/MPG.0b013e318290d15a

13. Wang, CH, Finkel, RS, Bertini, ES, Schrot, M, Simonds, A, Wong B. Consensus statement for standard of care in spinal muscular atropphy. J Child Neurol. 2007;22(8):1027-1049.

14. Hoeffel JC, Lascombes P, Schmitt M, Galloy MA. [Peptic esophagitis and scoliosis in children]. Ann Pediatr (Paris). 1992;39(9):561-565.