NIH Clinical Research Studies

Protocol Number: 01-DC-0230

Active Accrual, Protocols Recruiting New Patients

Studies of Deficits in the Sense of Taste
This study will explore the genetics of taste and taste deficits. The sense of taste plays a crucial role in food choices, allowing people to identify beneficial foods (those with high caloric value, which are typically sweet) and foods likely to be toxic (usually bitter substances). The loss of sense of taste in older people plays a role in decreased appetite and poor nutrition. Taste deficits may adversely affect people in ways that are not well understood. This study will examine why some people (about one-fourth of all people in the United States) cannot taste a substance called phenylthiocarbamide (PTC). The inability to taste PTC is due to inherited factors that are not yet clear.

Individuals age 18 and older who can taste PTC and individuals who cannot taste PTC may be eligible for this study. Participants will taste a number of liquid solutions until they find one with a clear taste. Then they will taste another group of solutions and decide which ones have that taste and which have no taste. Finally, they will taste a third group of solutions until they find one with a different taste. About 2 tablespoons of blood will be drawn from participants for genetic tests related to the sense of taste.

Sponsoring Institute:
National Institute on Deafness and Other Communication Disorders (NIDCD)
Recruitment Detail
Type: Participants currently recruited/enrolled
Gender: Male & Female
Referral Letter Required: No
Population Exclusion(s): Children

Eligibility Criteria:

This study includes medically normal individuals age 18 and older. This study includes both males and females, and includes members of all racial and ethnic groups. This study includes both individuals with a normal sense of taste, those unable to taste PTC, and those with varying degrees of taste sensitivity for other taste substances.


Individuals excluded will be those under age 18, those who are cognitively impaired, those with a physical impairment in swallowing, those who have general impairments in the sense of taste, those currently using psychoactive medication, prisoners, or other at-risk populations.

Special Instructions:
Currently Not Provided
Population Associations
Recruitment Keyword(s):
Healthy Volunteer
Normal Control
Taste Disorder
Investigational Drug(s):
Investigational Device(s):
Supporting Site:
National Institute on Deafness and Other Communication Disorders

Patient Recruitment and Public Liaison Office
Building 61
10 Cloister Court
Bethesda, Maryland 20892-4754
Toll Free: 1-800-411-1222
TTY: 301-594-9774 (local),1-866-411-1010 (toll free)
Fax: 301-480-9793


Phenylthiocarbamide taste sensitivity revisited: complete sorting test supports residual family resemblance

A novel family of mammalian taste receptors

Linkage relations of the loci for Kell and phenylthiocarbamide taste sensitivity

Active Accrual, Protocols Recruiting New Patients

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