Utilization and diagnostic yield of neurogenetic testing at a tertiary care facility.
BACKGROUND
Institutions face increasing charges related to molecular genetic testing for neurological diseases. The literature contains little information on the utilization and performance of these tests.


METHODS
A retrospective utilization review was performed to determine the diagnostic yield of neurogenetic tests ordered during calendar year 2005 at a large academic medical center in the western United States.


RESULTS
Overall, a relevant mutation was identified in 30.2% of the 162 patients tested and in 21.5% of the 121 probands, defined as patients for whom no mutation has been previously identified in a family member. Patients with muscle weakness (n = 65) had a mutation detected in 26.2% of all patients and 23.5% of probands (n = 51), with an estimated testing cost per positive result of $3190. Patients tested for neuropathy (n = 36) had a mutation detected in 27.8% of patients and 22.6% of probands (n = 31), with an estimated cost per positive result of $5955. Patients with chorea (n = 25) had a positive result obtained in 68% of patients and 71.4% of probands (n = 7); the estimated cost per positive test was $440. Other diagnostic categories evaluated include ataxias (n = 18; yield, 11.1%; $7620 per positive), familial stroke or dementia syndromes (n = 8; yield, 12.5%; $6760 per positive), and multisystem mitochondrial disorders (n = 10; yield, 20%; $6485 per positive).


CONCLUSIONS
Expert clinicians at a tertiary care center who ordered neurogenetic tests obtained a positive result in 21.5% of patients without previously identified familial mutations. These results can be used for comparison and to help establish utilization guidelines for neurogenetic testing.
Edlefsen
Kerstin L
KL
Department of Laboratory Medicine, University of Washington School of Medicine, Seattle, WA 98195-7110, USA.
Tait
Jonathan F
JF
Wener
Mark H
MH
Astion
Michael
M
D000046:Academic Medical Centers; D000293:Adolescent; D001259:Ataxia / Q000175:diagnosis / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D002819:Chorea / Q000175:diagnosis / Q000235:genetics; D003704:Dementia / Q000235:genetics; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D028361:Mitochondrial Diseases / Q000175:diagnosis / Q000235:genetics; D025202:Molecular Diagnostic Techniques / Q000191:economics / Q000379:methods / Q000706:statistics & numerical data; D009422:Nervous System Diseases / Q000175:diagnosis / Q000235:genetics*; D009468:Neuromuscular Diseases / Q000175:diagnosis / Q000235:genetics; D020521:Stroke / Q000235:genetics