Arg133Cys mutation of Notch3 in two unrelated Japanese families with CADASIL.
OBJECTIVE
More than 80 unrelated, but all Caucasian, patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), originating from various communities around the world, have been molecularly identified. To clarify the occurrence of CADASIL in Orientals, we investigated Japanese families presenting as CADASIL.


METHODS
We performed the PCR-SSCP and sequence analyses using genomic DNA, isolated from venous blood of participants under informed consent.


METHODS
We identified two unrelated Japanese families with CADASIL, including 5 affected members through 2 generations.


RESULTS
Each of the affected individuals developed recurrent strokes without risk factors resulting in progressive dementia, pseudobulbar palsy, and gait disturbances which started after the fifth decade of life. Although affected individuals had no vascular risk factors, they showed various degrees of narrowing of retinal arteries. Their MRI/CTs showed characteristics of the disease; bilateral small infarcts in the thalamus, basal ganglia, brain stem, and deep white matter in addition to the findings of leukoaraiosis. On SPECT imaging, there was severe hypoperfusion in the cortex as well as in the white matter. Ultrastructural studies revealed an abnormal deposition of granular osmiophilic materials (GOM) within the basal lamina of pericytes in muscular capillaries. On PCR-SSCP and sequence analyses, a heterozygous Arg133Cys mutation was present, in the affected individuals, in the exon 4 of Notch3 gene which is the hot spot region for CADASIL mutations in Caucasian families. None of the non-affected members nor the 50 Japanese normal controls revealed this mutation.


CONCLUSIONS
Thus, our results confirm that CADASIL is a geographically widespread disorder caused by a Notch3 mutation.
Uyama
E
E
Department of Neurology, Kumamoto University School of Medicine.
Tokunaga
M
M
Suenaga
A
A
Kotorii
S
S
Kamimura
K
K
Takahashi
K
K
Tabira
T
T
Uchino
M
M
D001120:Arginine / Q000235:genetics; D001921:Brain / Q000473:pathology; D003553:Cystine / Q000235:genetics; D004252:DNA Mutational Analysis; D017931:DNA Primers / Q000737:chemistry; D015161:Dementia, Multi-Infarct / Q000175:diagnosis / Q000208:ethnology / Q000235:genetics*; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D000071656:Receptor, Notch3; D011956:Receptors, Cell Surface; D051880:Receptors, Notch; D017422:Sequence Analysis, DNA
D017931:DNA Primers; C499374:NOTCH3 protein, human; D011518:Proto-Oncogene Proteins; D000071656:Receptor, Notch3; D011956:Receptors, Cell Surface; D051880:Receptors, Notch; D003553:Cystine; D001120:Arginine