A rare Asian founder polymorphism of Raptor may explain the high prevalence of Moyamoya disease among East Asians and its low prevalence among Caucasians.
BACKGROUND
In an earlier study, we identified a locus for Moyamoya disease (MMD) on 17q25.3.


METHODS
Linkage analysis and fine mapping were conducted for two new families in additional to the previously studied 15 families. Three genes, CARD14, Raptor, and AATK, were selected based on key words, namely, "inflammation", "apoptosis", "proliferation", and "vascular system", for further sequencing. A segregation analysis of 34 pedigrees was performed, followed by a case-control study in Japanese (90 cases vs. 384 controls), Korean (41 cases vs. 223 controls), Chinese (23 cases and 100 controls), and Caucasian (25 cases and 164 controls) populations.


RESULTS
Linkage analysis increased the LOD score from 8.07 to 9.67 on 17q25.3. Fine mapping narrowed the linkage signal to a 2.1-Mb region. Sequencing revealed that only one newly identified polymorphism, ss161110142, which was located at position -1480 from the transcription site of the Raptor gene, was common to all four unrelated sequenced familial affected individuals. ss161110142 was then shown to segregate in the 34 pedigrees studied, resulting in a two-point LOD score of 14.2 (P = 3.89 × 10(-8)). Its penetrance was estimated to be 74.0%. Among the Asian populations tested (Japanese, Korean, and Chinese), the rare allele was much more frequent in cases (26, 33, and 4%, respectively) than in controls (1, 1, and 0%, respectively) and was associated with an increased odds ratio of 52.2 (95% confidence interval 27.2-100.2) (P = 2.5 × 10(-49)). This allele was, however, not detected in the Caucasian samples. Its population attributable risk was estimated to be 49% in the Japanese population, 66% in the Korean population, and 9% in the Chinese population.


CONCLUSIONS
ss161110142 may confer susceptibility to MMD among East Asian populations.


BACKGROUND
The online version of this article (doi:10.1007/s12199-009-0116-7) contains supplementary material, which is available to authorized users.
Liu
Wanyang
W
Hashikata
Hirokuni
H
Inoue
Kayoko
K
Matsuura
Norio
N
Mineharu
Yohei
Y
Kobayashi
Hatasu
H
Kikuta
Ken-Ichiro
K
Takagi
Yasushi
Y
Hitomi
Toshiaki
T
Krischek
Boris
B
Zou
Li-Ping
LP
Fang
Fang
F
Herzig
Roman
R
Kim
Jeong-Eun
JE
Kang
Hyun-Seung
HS
Oh
Chang-Wan
CW
Tregouet
David-Alexandre
DA
Hashimoto
Nobuo
N
Koizumi
Akio
A