Contrasting genotypes of the tau gene in two phenotypically distinct patients with P301L mutation of frontotemporal dementia and parkinsonism linked to chromosome 17.
Association between clinical characteristics and types of the tau gene mutation has been observed in frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17). P301L mutation seldom causes parkinsonism as a leading symptom; instead it usually causes personality changes with aggressiveness and disinhibition. We experienced two patients of FTDP-17 from separate families (designated as patient 1 from family 1 and patient 2 from family 2). They had P301L mutation in common. However, their phenotypes were distinct from each other. Aggressive behaviors and disinhibition were the main symptoms in patient 1, whereas parkinsonism was the most prominent feature in patient 2. Their genotypes of the tau gene were different at three sites, i. e. in exon 6, in intron segment before exon 10, and in exon 13, though they do not bring amino acid change. Patient 1 had more prevalent C/C, C/C, and rare T/C respectively. Patient 2 had less prevalent T/T, A/A, and more prevalent T/T respectively. These findings suggest two things. Firstly, they do not share a common founder for P301L mutation. Secondly, either of the two less prevalent genotypes observed in patient 2 may be the factor to modify the phenotype of P301L mutation into those unusual clinical features with prominent parkinsonism. Accumulation of information as to phenotype-genotype association will settle this hypothesis.
Kobayashi
Tomonori
T
Department of Neurology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan. tomo@med.juntendo.ac.jp
Mori
Hideo
H
Okuma
Yasuyuki
Y
Dickson
Dennis W
DW
Cookson
Natalie
N
Tsuboi
Yoshio
Y
Motoi
Yumiko
Y
Tanaka
Ryota
R
Miyashita
Nobuo
N
Anno
Midori
M
Narabayashi
Hirotaro
H
Mizuno
Yoshikuni
Y
D017668:Age of Onset; D000595:Amino Acid Sequence / Q000235:genetics; D001483:Base Sequence / Q000235:genetics; D001921:Brain / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D002886:Chromosomes, Human, Pair 17 / Q000235:genetics*; D004252:DNA Mutational Analysis; D003704:Dementia / Q000150:complications / Q000235:genetics* / Q000378:metabolism; D005091:Exons / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D005820:Genetic Testing; D005838:Genotype; D006801:Humans; D007564:Japan; D008297:Male; D001523:Mental Disorders / Q000235:genetics / Q000503:physiopathology; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D020734:Parkinsonian Disorders / Q000150:complications / Q000235:genetics* / Q000378:metabolism; D010375:Pedigree; D010641:Phenotype; D011110:Polymorphism, Genetic / Q000235:genetics; D016875:tau Proteins / Q000235:genetics* / Q000378:metabolism
D016875:tau Proteins