Univerricht-Lundborg disease: underdiagnosed in the Netherlands.
OBJECTIVE
Univerricht-Lundborg disease (ULD), with its major symptom of action myoclonus, is supposed to be very rare in the Netherlands and western Europe. We hypothesized that the syndrome may be underdiagnosed in patients with myoclonus epilepsy.


METHODS
Mutation analysis of the cystatin B gene was performed in 21 cases with uncontrolled myoclonus.


RESULTS
Seven of the 21 evaluated cases carried mutations in the cystatin B gene. Diagnosis of ULD was made with a mean delay of 20 years from symptom onset.


CONCLUSIONS
This study from a country without previous reports of ULD suggests that underdiagnosis of the syndrome is likely. These findings also indicate that persons with juvenile-onset myoclonus epilepsy with action myoclonus should be analyzed for ULD.
Epilepsy Institute of the Netherlands SEIN, Heemstede, the Netherlands.
Gerrit-Jan
GJ
de Haan
Dicky J J
DJ
Halley
Jan C
JC
Doelman
Huibert H
HH
Geesink
Paul B
PB
Augustijn
Anke D
AD
Jager-Jongkind
Marianne
M
Majoie
Adri J
AJ
Bader
Lian A W M
LA
Leliefeld-Ten Doeschate
Wout H
WH
Deelen
Ed
E
Bertram
Anna E
AE
Lehesjoki
Dick
D
Lindhout
D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D002648:Child; D002675:Child, Preschool; D003241:Consanguinity; D055313:Cystatin B; D015891:Cystatins / Q000235:genetics; D004252:DNA Mutational Analysis; D003937:Diagnosis, Differential; D004641:Emigration and Immigration / Q000706:statistics & numerical data; D005260:Female; D005820:Genetic Testing; D006801:Humans; D008297:Male; D009154:Mutation / Q000235:genetics; D020190:Myoclonic Epilepsy, Juvenile / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics; D009426:Netherlands / Q000453:epidemiology; D010775:Photic Stimulation / Q000009:adverse effects; D020194:Unverricht-Lundborg Syndrome / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics*; D044465:White People / Q000235:genetics / Q000706:statistics & numerical data
C524994:CSTB protein, human; D015891:Cystatins; D055313:Cystatin B