++
Rare familial form of subacute spongiform
encephalopathy resulting in widespread
degeneration of the nervous system, usually beginning in the fourth or fifth
decade of life. Special consideration must be given to potential
contamination of the attending personnel, other patients, and medical
materials.
++
Amyloid Dependent Subacute Spongiform Encephalopathy;
Cerebellar Ataxia-Progressive Dementia Syndrome; Cerebellar Ataxia with
Progressive Dementia and Amyloid Deposits in CNS; Cerebral Amyloidosis with
Spongiform Encephalopathy Syndrome; Gerstmann Syndrome I;
Gerstmann-Sträussler-Scheinker Disease (or Syndrome); Prion Dementia;
Sträussler Disease (or Syndrome); Subacute Spongiform Encephalopathy,
Gerstmann-Sträussler Type.
++
Rare; incidence estimated to be 1-10:100,000,000 in the
general population.
++
Autosomal dominant with point mutation of the
prion protein gene (20 different mutations of the human PrP gene are
reported). Gene map locus is 20pter-p12.
++
Evidence indicates this disorder is caused by
mutation in the prion protein gene (PRNP). PrPC is a normal glycoprotein
that seems to have a central role in the pathogenesis of transmissible
subacute spongiform encephalopathies. The isoform, which is associated with the disease, is the result of a
conformational change of PrPC and designated PrPSc.
Mutations in the 102nd codon of the PrP gene can produce neurodegeneration, which
is the main feature of the prion diseases.
++
Classified with other transmissible spongiform
encephalopathies that represent a group of neurodegenerative diseases
with lethal outcome. The differential diagnosis between Creutzfeldt-Jakob
disease (CJD) and
Gerstmann-Sträussler disease (GSD) has proved to be difficult because of the
clinical similarities. However, it differs histologically from CJD by the
presence of Kuru-type amyloid plaques and numerous multicentric, floccular
plaques in the cerebral and cerebellar cortex, basal ganglia, and white
matter. Whereas only 5 to 15% of CJD cases are familial, most cases of
GSD are familial. In addition to spinocerebellar and corticospinal tract
degeneration, extensive amyloid plaques are found throughout the CNS, and in
many cases spongiform degeneration is found. An abnormal isoform of prion
protein (PrP) in the brain can be detected by Western blotting and
immunohistochemistry.
++
Characterized by cerebellar ataxia, progressive
dementia, and absent reflexes in the legs. Onset is usually in the fifth
decade of life. In the early phase, ataxia is predominant. Dementia develops later.
Atactic symptoms, dysarthria, and personality changes characterize the
clinical course of this disorder. Pyramidal, pseudobulbar, or cerebellar
symptoms (usually preceding dementia), age of onset, course, and familial
character of the disorder distinguish it among presenile dementias. The
disease course ranges from 2 to 10 years. There is a progressive decline of physical
and intellectual function until death.
++
Prions are highly resistant to
traditional disinfection and sterilization processes. Patients known to
have, or suspected of having, transmissible prion diseases, such as CJD and
GSD, should be managed in the hospital ward with precautionary measures
similar to those used for patients with hepatitis B or acquired immune
deficiency syndrome.
++
Unlike iatrogenic CJD, there have been
no cases of GSD as a result of iatrogenic spread. ...