How is Hirschsprung Disease inherited?
Hirschsprung disease can either be isolated or syndromic. Isolated Hirschsprung disease is found in a child or infant who does not have other serious health conditions. Isolated Hirschsprung disease can be sporadic, meaning the cause is unknown, or can be inherited, meaning a specific gene change is causing Hirschsprung disease. Genes are the basic unit of heredity. Genes are made of DNA and are instructions to make proteins and molecules inside the cells that make up the body.
If Hirschsprung disease is inherited, it can be inherited in an autosomal dominant or autosomal recessive pattern. Autosomal dominant means that a person only needs one copy of the affected gene from a single parent to have Hirschsprung disease. If a parent has a gene change causing autosomal dominant Hirschsprung disease there is a 50% chance it will be passed to each child causing the child to have Hirschsprung disease. Autosomal recessive means a person must have two copies of an affected gene, one from mom and one from dad, in order to have the condition. If each parent carries a gene change causing autosomal recessive Hirschsprung disease there is a 25% chance that each child will have Hirschsprung disease. The type of inheritance depends on the gene.
In some children and infants Hirschsprung disease is part of a larger syndrome. A genetic syndrome is a group of signs and symptoms that occur together and characterize a particular abnormality. Some syndromes that can include Hirschsprung disease are Waardenburg syndrome, Mowat-Wilson syndrome, congenital central hypoventilation syndrome and Down syndrome or Trisomy 21. These conditions may have other inheritance patterns and risks for having Hirschsprung disease.
To learn more about inheritance of Hirschsprung disease speak with your physician or a genetic counselor. To locate a genetic counselor near you use the Find a Genetic Counselor tool on the National Society of Genetic Counselors website.
"Hirschsprung Disease" Genetics Home Reference. Aug. 2012. http://ghr.nlm.nih.gov/condition/hirschsprung-disease
"Hirschsprung Disease Overview" GeneReviews. 01 Oct. 2015. Web. 14 Jun. 2016. http://www.ncbi.nlm.nih.gov/books/NBK1439/