Lack of support for the inability to taste phenylthiocarbamide as an endophenotypic marker in patients with schizophrenia and their first-degree relatives.
OBJECTIVE
This study sought to replicate recent findings that both patients and relatives are significantly more likely to be phenylthiocarbamide (PTC) nontasters than healthy controls, and that within the patient group, nontasters have more severe positive and/or negative symptoms than tasters. Associations between PTC-tasting status and olfactory identification scores also were examined.


METHODS
PTC perception and olfactory identification were assessed in 48 patients with schizophrenia or schizoaffective disorder, 28 first-degree relatives, and 32 healthy volunteers.


RESULTS
The three groups did not differ in PTC taste sensitivity. Findings did not change after: a sensitivity analysis that re-categorized participants who "possibly" tasted PTC, excluding Caucasian participants, or restricting the sample of patients to only those with schizophrenia. Among the patients, tasters and nontasters did not differ with regard to positive, negative, or general psychopathology symptoms. In the combined sample and the three groups separately, there were no associations between PTC-tasting status and olfactory identification scores.


CONCLUSIONS
This study, conducted specifically as an attempt to replicate previously reported findings, failed to provide support for PTC perception as an endophenotypic marker for schizophrenia. Further research is warranted.
Compton
Michael T
MT
Emory University School of Medicine, 49 Jesse Hill Jr. Drive, S.E., Room #333, Atlanta, GA 30303, USA. mcompto@emory.edu
Chien
Victoria H
VH
Bollini
Annie M
AM
Walker
Elaine F
EF
D000328:Adult; D035061:Control Groups; D039721:Diagnostic and Statistical Manual of Mental Disorders; D004408:Dysgeusia / Q000175:diagnosis* / Q000235:genetics*; D005190:Family / Q000523:psychology*; D005260:Female; D005819:Genetic Markers / Q000235:genetics*; D006801:Humans; D008297:Male; D010641:Phenotype; D010670:Phenylthiourea; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D012559:Schizophrenia / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics*; D012565:Schizophrenic Psychology; D013652:Taste Threshold / Q000235:genetics
D005819:Genetic Markers; D010670:Phenylthiourea