Hirschsprung disease

What it is, symptoms and effects

From: MedlinePlus Genetics, National Library of Medicine

Hirschsprung disease is an intestinal disorder characterized by the absence of nerves in parts of the intestine. This condition occurs when the nerves in the intestine (enteric nerves) do not form properly during development before birth (embryonic development). This condition is usually identified in the first two months of life, although less severe cases may be diagnosed later in childhood.

Enteric nerves trigger the muscle contractions that move stool through the intestine. Without these nerves in parts of the intestine, the material cannot be pushed through, causing severe constipation or complete blockage of the intestine in people with Hirschsprung disease. Other signs and symptoms of this condition include vomiting, abdominal pain or swelling, diarrhea, poor feeding, malnutrition, and slow growth. People with this disorder are at risk of developing more serious conditions such as inflammation of the intestine (enterocolitis) or a hole in the wall of the intestine (intestinal perforation), which can cause serious infection and may be fatal.

There are two main types of Hirschsprung disease, known as short-segment disease and long-segment disease, which are defined by the region of the intestine lacking nerve cells. In short-segment disease, nerve cells are missing from only the last segment of the large intestine (colon). This type is most common, occurring in approximately 80 percent of people with Hirschsprung disease. For unknown reasons, short-segment disease is four times more common in men than in women. Long-segment disease occurs when nerve cells are missing from most of the large intestine and is the more severe type. Long-segment disease is found in approximately 20 percent of people with Hirschsprung disease and affects men and women equally. Very rarely, nerve cells are missing from the entire large intestine and sometimes part of the small intestine (total colonic aganglionosis) or from all of the large and small intestine (total intestinal aganglionosis).

Hirschsprung disease can occur in combination with other conditions, such as Waardenburg syndrome, type IV; Mowat-Wilson syndrome; or congenital central hypoventilation syndrome. These cases are described as syndromic. Hirschsprung disease can also occur without other conditions, and these cases are referred to as isolated or nonsyndromic.

Causes and biological mechanisms

From: MedlinePlus Genetics, National Library of Medicine

Isolated Hirschsprung disease can result from mutations in one of several genes, including the RET, EDNRB, and EDN3 genes. However, the genetics of this condition appear complex and are not completely understood. While a mutation in a single gene sometimes causes the condition, mutations in multiple genes may be required in some cases. The genetic cause of the condition is unknown in approximately half of affected individuals.

Mutations in the RET gene are the most common known genetic cause of Hirschsprung disease. The RET gene provides instructions for producing a protein that is involved in signaling within cells. This protein appears to be essential for the normal development of several kinds of nerve cells, including nerves in the intestine. Mutations in the RET gene that cause Hirschsprung disease result in a nonfunctional version of the RET protein that cannot transmit signals within cells. Without RET protein signaling, enteric nerves do not develop properly. Absence of these nerves leads to the intestinal problems characteristic of Hirschsprung disease.

The EDNRB gene provides instructions for making a protein called endothelin receptor type B. When this protein interacts with other proteins called endothelins, it transmits information from outside the cell to inside the cell, signaling for many important cellular processes. The EDN3 gene provides instructions for a protein called endothelin 3, one of the endothelins that interacts with endothelin receptor type B. Together, endothelin 3 and endothelin receptor type B play an important role in the normal formation of enteric nerves. Changes in either the EDNRB gene or the EDN3 gene disrupt the normal functioning of the endothelin receptor type B or the endothelin 3 protein, preventing them from transmitting signals important for the development of enteric nerves. As a result, these nerves do not form normally during embryonic development. A lack of enteric nerves prevents stool from being moved through the intestine, leading to severe constipation and intestinal blockage.

Inheritance and family implications

From: MedlinePlus Genetics, National Library of Medicine

Approximately 20 percent of cases of Hirschsprung disease occur in multiple members of the same family. The remainder of cases occur in people with no history of the disorder in their families.

Hirschsprung disease appears to have a dominant pattern of inheritance, which means one copy of the altered gene in each cell may be sufficient to cause the disorder. The inheritance is considered to have incomplete penetrance because not everyone who inherits the altered gene from a parent develops Hirschsprung disease.

How common is it?

From: MedlinePlus Genetics, National Library of Medicine

Hirschsprung disease occurs in approximately 1 in 5,000 newborns.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Abdominal pain · Very frequent (99-80%)

An unpleasant sensation characterized by physical discomfort (such as pricking, throbbing, or aching) and perceived to originate in the abdomen.

Aganglionic megacolon · Very frequent (99-80%)

An abnormality resulting from a lack of intestinal ganglion cells (i.e., an aganglionic section of bowel) that results in bowel obstruction with enlargement of the colon.

Constipation · Very frequent (99-80%)

Infrequent or difficult evacuation of feces.

Functional abnormality of the gastrointestinal tract · Very frequent (99-80%)

Abnormal functionality of the gastrointestinal tract.

Intestinal obstruction · Very frequent (99-80%)

Blockage or impairment of the normal flow of the contents of the intestine towards the anal canal.

Nausea and vomiting · Very frequent (99-80%)

Nausea is a commonly encountered symptom that has been defined as an unpleasant painless subjective feeling that one will imminently vomit. Vomiting has been defined as the forceful expulsion of the contents of the stomach, duodenum, or jejunum through the oral cavity. While nausea and vomiting are often thought to exist on a temporal continuum, this is not always the case. There are situations when severe nausea may be present without emesis and less frequently, when emesis may be present without preceding nausea.

Abdominal distention · Frequent (79-30%)

Distention of the abdomen.

Bilious emesis · Frequent (79-30%)

Vomiting whereby the vomit has the color of bile, yellowish-green.

Other findings in the same source

From: Orphanet

Additional reported features include Delayed passage of meconium (Frequent (79-30%)); Feeding difficulties (Frequent (79-30%)); Weight loss (Frequent (79-30%)); Colon perforation (Occasional (29-5%)); Diarrhea (Occasional (29-5%)); Enterocolitis (Occasional (29-5%)); Growth delay (Occasional (29-5%)); Polyhydramnios (Occasional (29-5%)); Sepsis (Occasional (29-5%)); Short stature (Occasional (29-5%)). This is a selected summary, not a complete description of the condition.

Which doctor should you see?

The suggested department for discussing Hirschsprung disease is Gastroenterology, with a gastroenterologist as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

Additional services that may be relevant, depending on the findings, include: Clinical Genetics.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Which digestive symptoms or nutritional changes matter most?
• What question would an endoscopy, scan or laboratory test answer if one is proposed?
• How should persistent pain, bleeding or difficulty eating be followed up?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Hirschsprung disease. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.