Gastrointestinal (GI) Problems in Angelman and How to Deal With Them
People with Angelman syndrome may experience gastrointestinal (GI) problems in addition to physical and intellectual symptoms. Here is information about common GI problems in Angelman, how doctors treat them, and what patients and caregivers can do to help ease their symptoms.
What is Angelman syndrome?
Angelman syndrome is a rare genetic disorder caused by issues with the UBE3A gene on chromosome 15. The UBE3A gene contains the information necessary for cells to produce the ubiquitin-protein ligase 3A enzyme. This enzyme plays a role in a pathway that labels proteins so cells can break them down.
People generally receive two copies of each gene, one from each biological parent. However, in some cells of the body, only one copy of a gene is active. For example, only the maternal copy of the UBE3A gene is active in many cells of the nervous system. When there is a mutation in this copy, patients develop Angelman syndrome.
What GI symptoms occur in Angelman?
Researchers have reported several GI symptoms in patients with the neurological disorder. A study analyzing the medical records of 163 Angelman syndrome patients, published in 2017, found that 141 (86.5%) had some form of GI impairment. The most common of these, in 116 patients, was constipation; the second most frequent GI problem, occurring in 72 patients, was gastroesophageal reflux disease (GERD), a condition in which stomach acid can flow back into the esophagus. Other issues included difficulty swallowing, excessive amounts of swallowing, cyclic vomiting, and eosinophilic esophagitis, in which a large number of white blood cells called eosinophils build up in the lining of the esophagus and cause irritation. Of note, cyclic vomiting occurs when a patient experiences periods of vomiting with no obvious cause such as illness or food allergy.
Young patients with Angelman syndrome also may experience difficulties in sucking as infants, and with excessive drooling, both of which can cause issues with feeding. Individuals with trouble swallowing, excessive drooling, and GERD also have a risk of aspiration, or having food or liquid accidentally pass into the lungs.
How might Angelman cause GI symptoms?
The exact mechanism of how Angelman syndrome causes GI symptoms is not clear. However, specific types of mutations may make patients more prone to certain issues. For example, upper GI symptoms — symptoms involving the mouth, esophagus, and stomach — seem to be more common in patients who have deletions or paternal uniparental disomy, which means they have two copies of chromosome 15 from the father with none from the mother. Early feeding issues in infants also may occur with higher frequency in patients with chromosome deletions, likely due to the involvement of multiple genes causing low muscle tone.
The frequency of constipation seems to be the same in all genetic subtypes of Angelman. It may have multiple causes, including anxiety, lack of sensation related to having to go to the bathroom, and lack of a specific bathroom routine.
Many Angelman patients have seizures and may be taking antiepileptic drugs (AEDs) to control them. Such AEDs also can cause constipation. Some patients also may be on low glycemic index diets to treat their seizures, which have been found to sometimes lead to constipation.
How do doctors treat GI symptoms in Angelman?
Dietary modifications such as more fiber and more water can ease constipation. Doctors also may treat constipation with medications such as laxatives. Switching to a different AED may help for some patients. In severe cases, glycerine suppositories may be necessary.
Keeping an upright position when eating or sleeping may help patients with GERD, as can medications that reduce the acidity of the stomach or that can make food move more quickly through the digestive tract (motility drugs). There are also surgical options that can make it harder for gastric juices to leak back into the esophagus.
For infants with sucking issues, modified breastfeeding methods or bottles with special nipples may be helpful.
Excessive drooling can be treated with medications to reduce the amount of saliva being produced or with surgery.
For patients who are at risk of aspiration or who are failing to get sufficient nutrition due to feeding issues, feeding tubes placed directly into the stomach (gastrostomy) may be an option.
Last updated: Nov. 9, 2020
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