Genetics of tension-type headache.

Area of Science:

• Neurology
• Genetics
• Epidemiology

Background:

• Tension-type headache (TTH) is a common neurological disorder with a prevalence ranging from 11% to 93%.
• The co-occurrence of migraine can increase the frequency of TTH.
• Understanding the etiological factors, including genetic and environmental influences, is crucial for managing TTH.

Purpose of the Study:

• To investigate the genetic contribution to the development of tension-type headache.
• To differentiate the genetic and environmental influences on various forms of TTH (infrequent, frequent episodic, and chronic).

Main Methods:

• A comprehensive literature search was conducted using MEDLINE from 1966 to December 2006.
• Keywords used included "tension-type headache and prevalence" and "tension-type headache and genetics".
• Analysis included family and twin studies to assess genetic heritability.

Main Results:

• Family studies suggest a significant role for genetic factors in chronic TTH.
• Twin studies indicate a minor genetic role in episodic TTH, especially when co-occurring with migraine.
• Higher concordance rates in monozygotic twins compared to dizygotic twins suggest genetic influence in frequent episodic TTH without migraine.
• Infrequent episodic TTH showed minimal genetic influence, indicating primary environmental causation.

Conclusions:

• Frequent episodic and chronic TTH result from a combination of genetic and environmental factors.
• Infrequent episodic TTH is predominantly caused by environmental factors.
• Genetic predisposition appears more significant in severe forms of TTH.