Prion disease with octapeptide repeat insertion.
OBJECTIVE
About 8% of prion disease cases are familial and a few are due to an octapeptide repeat insertion (OPRI) in the prion protein gene. A suitable neuropathological examination has been performed in 20 cases from 9 families and in 3 isolated cases. The number of OPRI ranges from 4 to 9 multiples of 24 base-pair.


METHODS
Results from routine histopathological preparations and from immunohistochemistry performed after special tissue pretreatment were compared with those of molecular genetic investigation.


RESULTS
Eight cases with 4 to 7 multiples of OPRI exhibited characteristic elongated deposits in the cerebellar molecular layer, which were visible on slides prepared with antibodies against the prion protein only. Conversely, 6 cases with 8 or 9 multiples of OPRI presented typical plaques already obvious on routine preparations.


CONCLUSIONS
These variable modifications in the cerebellar molecular layer deserve to be underlined, in particular the elongated deposits which are characteristic for cases presenting 4 to 7 OPRI.
Vital
C
C
Laboratoire de Neuropathologie, Université Victor Segalen, Bordeaux.
Gray
F
F
Vital
A
A
Ferrer
X
X
Julien
J
J
D000328:Adult; D002531:Cerebellum / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017096:Prion Diseases / Q000235:genetics* / Q000473:pathology; D011328:Prions / Q000235:genetics*; D020449:Repetitive Sequences, Amino Acid
D011328:Prions