Laryngeal Cleft Symptoms Diagnosis Treatment FAQs Definitions
Genetics
The exact cause of most laryngeal clefts is not yet fully understood. While some laryngeal clefts occur as part of a known genetic condition, others occur as an isolated anomaly. In many children, the underlying cause remains unknown.
Genetic Conditions
A laryngeal cleft may occur as part of several genetic conditions, including:
22q11.2 deletion syndrome
CHARGE syndrome
VACTERL association
Opitz G/BBB syndrome
Pallister-Hall syndrome
However, not every child with one of these conditions has a laryngeal cleft, and most children with a laryngeal cleft do not have one of these diagnoses.
Inheritance Patterns
Genes are made of DNA and provide instructions for how our bodies grow, develop, and function.
Humans inherit 23 chromosomes from each parent, and each chromosome contains hundreds to thousands of genes. For most genes, a child receives one copy from each parent.
Common genetic inheritance patterns include:
Autosomal dominant: A change in one copy of a gene may be enough to cause a condition.
Autosomal recessive: Changes in both copies of a gene are typically required to cause a condition.
De novo (new) variants: A genetic change occurs for the first time in a child and is not inherited from either parent.
“Most causes of laryngeal clefts are unknown. In some cases, a laryngeal cleft may be caused by a de novo genetic variant and in other cases, the cleft may be caused by a genetic variant passed down in the family. More research is needed to begin to recognize the genetic causes.”
See CARE Study Overview and CARE Study FAQs for more information on laryngeal cleft genetics.
When Testing Is Normal
Current genetic testing cannot identify the cause of every laryngeal cleft. A normal genetic test result does not rule out a genetic cause.
When no genetic diagnosis is identified, several explanations are possible:
The cleft may not have a genetic cause.
The genetic cause may not yet be recognized by researchers.
The genetic cause may not yet be detectable with current testing methods.
Multiple genetic and/or environmental factors may contribute, making the cause more complex to identify.
Ongoing Research
Research is ongoing to improve our understanding of the genetics of laryngeal clefts. By studying the genetic information from many families with laryngeal clefts, researchers hope to identify additional genetic factors that contribute to the development of the condition.
As genetic knowledge and testing methods continue to advance, previously unrecognized causes may be identified.
Medically reviewed in 2026 by:
Wendy Chung, MD, PhD — Pediatrics, Boston Children's Hospital