Table 1.

Demographic and clinical features of homozygous PRNP mutations in the literature

	Present study
	Spanish family	Portuguese family [14]	Beck et al [11]	Komatsu et al [12]	Simon et al [10]	Hassan et al [27]
Gender	2 female	2 male/1 female	Female	Female	3 male/2 female	Male
Country	Spain	Portugal	Ireland	Japan	Libya	China
Family history	Yes	Yes (siblings)	No (grandmother with dementia in later life)	No	Yes	Unknown
PRNP mutation	R136S	R136S	Q212P	V203I	E200K	E200D
Polymorhism codon 129	MM	MM	MM	MM	Unknown	MM
Phenotype	Gerstmann-Sträussler-Scheinker	Gerstmann-Sträussler-Scheinker	Unknown	genetic Creutzfeldt Jakob’s disease	genetic Creutzfeldt Jakob’s disease	Unknown
Cosanguinity	Yes	Unknown	Probable	Yes	Unknown	Probable
Age at onset (years)	43.5 ± 5.5	52 (female)	36	73	50.4 ± 6.2	61
Age of death (years)	50.5 ± 2.5	49.6 ± 6.4	Unknown	75	50.8 ± 8.2	61
Disease duration	7.25 ± 2.75 years	4 years	4 years	2 years	15.8 ± 15.9 years	10 weeks
Clinical symptoms	Progressive memory decline (2/2), language (1/2), executive disturbances (2/2)	Psychiatric symptoms, myoclonous, Parkinsonian symptoms, and progressive dementia	Dysarthria, ataxia, nystagmus, and executive dysfunction	Gait disturbance, cognitive dysfunction	Dementia (5/5), personality change (2/5), parkinsonism (4/5); myoclonus (2/5), gait ataxia (2/5), and dysarthria (3/5)	Confusion, dysarthria, ataxia, myoclonus, and hallucinations
14-3-3 protein	Negative	Negative	Unknown	Positive	Unknown	Negative
MRI brain	Normal	Normal	Moderate cerebral atrophy	Hyperintensity in basal ganglia and right frontal, parietal and occipital lobes	Unknown	Abnormal symmetric restricted bilateral diffusion in the striatum and cortex
EEG	Unknown	Lentified	Mildly abnormal	Diffuse slowing of waves	3/5 abnormal	Mild slowing only, with no periodic sharp ware complexes
Neuropathology	Multicentric amyloid PrP plaques, prominent neuronal loss, astrogliosis, and microglial proliferation	Multicentric amyloid PrP plaques, mild neuritic component, and microglial activation	N/A	N/A	1/2 did not display PrPres	N/A
PrP Western blotting	~ 8 kDa band	8 kDa and 5 kDa band	N/A	N/A	N/A	N/A
In vivo transmissibility studies	Negative	N/A	N/A	N/A	N/A	N/A
In vitro propagation studies	Negative	N/A	N/A	N/A	N/A	N/A