Trong thoi doi phat trien, benh to IcS can tar nen pha bien trong xa hc)i,.dac. Wet la a tre Khi benh mai ducc phat hien, nguai to cho rang nguyen nhan gay benh chit yeu do yeu to mai truing song, str thieu quan tam tir cha me va nh4ng nguai co trach nhiem day do. Tir da se clan den firth twig tre kern phat trien toin dien ve mat neon nga, giao tiep va gag hoat clang xa ,hai. Thai gian gin day, viec nghien ciru can benh nay da cO met buoc tien mai khi cac nha khoa hoc da bat dau tim ra nhitng gen c6 kha nang gay benh do xay ra hien Wong dot bien gen. Tir day, mat nhan dinh duoc dua ra de là benh tkr kjr co the c6 kha nang di truyen to bo,me sang con cal. Trong so nhung gen c6 kha nang gay benh, gen SHANK3 yeu to dung vao ir6 quan trong nhat, ben canh nhCrng gen khac nhu NLGN3, NLGN4X,... FISH (floumescent in situ hybridization) va aCGH (array comparative genomic hybridization) la hai phuong phap chinh duce sir dung de phat hien nhung sai khac tren gen hay tren nhiem sac the, ben canh d6 de xic nhan lai nhung thay dal do, phuong phip MLPA (multiplex ligation probe amplification) se duce clung den. Ben canh viec tim ra nhung rot loan ye di tntyen, nhimg lieu phap chera tri cling dirge ap dung de gin) cho benh nhan cc, the mph dan han trong viec giao tiep, trong nhung hoot dang xa hai va nhan biet nhung sit vat, hien tuong xung quanh. Tuy nhien, cho den nay, mat cau hei van chtra co lai giii la sit twang quan gifra kieu hinh, kieu gen cita benh va sv twang tic gifra nhimg yeu to di truyen va hoar girth m8i tnreng. Trong tuang lai gin, neu nhung thic mac nay c6 lei giii dap chinh xac thi se la mat tien ba len trong viec ngan chart va dieu tri can benh nay.
Trang 1BAI TONG QUAN
PHAP CHAN DOAN
Le Bic Vi0, Nang Van Hal, Nguyen Huy Mang
Vien Nghien ctitt he gen, Vien Han lam Khoa hoc vet Cong nghe Viet Nam
Ngay nhan bai:18.8.2013
Ngay nhan clang: 05.3.2014
TOM TAT
Trong thoi doi phat trien, benh to IcS/
rang
can tar nen pha bien trong xa hc)i,.dac Wet la a tre Khi
benh mai ducc phat hien, nguai to cho rang nguyen nhan gay benh chit yeu do yeu to mai truing song, str thieu quan tam tir cha me va nh4ng nguai co trach nhiem day do Tir da se clan den firth twig tre kern phat trien toin dien ve mat neon nga, giao tiep va gag hoat clang xa ,hai Thai gian gin day, viec nghien ciru can benh nay
da cO met buoc tien mai khi cac nha khoa hoc da bat dau tim ra nhitng gen c6 kha nang gay benh do xay ra hien Wong dot bien gen Tir day, mat nhan dinh duoc dua ra de là benh tkr kjr co the c6 kha nang di truyen to
bo ,me sang con cal Trong so nhung gen c6 kha nang gay benh, gen SHANK3 yeu to dung vao ir6 quan trong
nhat, ben canh nhCrng gen khac nhu NLGN3, NLGN4X, FISH (floumescent in situ hybridization) va aCGH
(array comparative genomic hybridization) la hai phuong phap chinh duce sir dung de phat hien nhung sai khac tren gen hay tren nhiem sac the, ben canh d6 de xic nhan lai nhung thay dal do, phuong phip MLPA (multiplex ligation probe amplification) se duce clung den Ben canh viec tim ra nhung rot loan ye di tntyen, nhimg lieu phap chera tri cling dirge ap dung de gin!) cho benh nhan cc!, the mph dan han trong viec giao tiep, trong nhung hoot dang xa hai va nhan biet nhung sit vat, hien tuong xung quanh Tuy nhien, cho den nay, mat cau hei van chtra co lai giii la sit twang quan gifra kieu hinh, kieu gen cita benh va sv twang tic gifra nhimg yeu
to di truyen va hoar' girth m8i tnreng Trong tuang lai gin, neu nhung thic mac nay c6 lei giii dap chinh xac thi se la mat tien ba len trong viec ngan chart va dieu tri can benh nay
Tit khoa: aCGH, benh ttr 4, di truyJn, &Of ban gen, FISH, gen SHANK3, MLPA
GIOI THIEU
Dinh nghia ve bdnh tv kY' len dAu tiep duqc nha
khoa hoc nguai My Leo Kanner dua ra vao nam
1943 Khi d6, ttr ky ducfc cho là benh gay ra nhimg
•
rot loan phat trien he than kinh a nguai benh bang
cach lam thay dOi su lien ket va to chin giaa to bao
thAn kinh va cac khop than kinh Benh thuOng bee
phat ngay tv khi benh nhan con nh6, nett kitting duric
phat hien semi va co nhang lieu phap dieu tri thich
hop, benh se ngay cang nang han va benh nhan
thuong c6 xu htrang tranh xa moi hoat &Ong xung
quanh mirth, khong muon tiep xtic vii nguai Ichfic va
c6 nhung hanh ding bit thu6ng
Ve ca ban, su thieu nhung hoat deng va giao
tiep xa hai, nen nga la diu hien not bat trong moi
berth nhan tv Icy Dar Ming là tieu chuin yang de
chin doin lam sang doi vii nhung ngirtri bi nghi nga
mac tv ki tai cac Benh vien chuyen khoa Nhi
Nguyen nhan ma tin tnrac den nay van duoc cho la
nye tiep va chit yeti nit& la sv thieu quan tam, chain s6c dimg each tir cha mg nal rieng va cac bac nuoi day n6i chung Chinh dieu nay da khiAn cho tit khong ductc, phattrien met each toan dien the,
chat, tinh than va dac biet là he than kink Lau dan, nhung roi loan ve than kinh tang dan len, tao nen 06 roi loan tu ky (autism spectrum disorders - ASD) yeti niang bieu hien rat ro rang ve tinh each, hanh Ong
va suy nghT (Autism Association, 1994)
Thai gian gin day, vii nhung nen ba nhay 'KA trong y hoc, sinh hoc phan tir, sinh hoc to bao, chin doin, mat nguyen nhan mai gay bath tkr kjf da,ittroc tim ra DO nhOng sv roi loan chuyen h6a, mat can bang sinh hOa trong ca the do det bien tren cac gen chirc nang gay ra Nhiffig gen nay m4 Ma cho clic protein lien quan trVc tiep den he thong than kinh
va nhting khap than kinh trong ca the Do do, (tat bien xay ra ten nh!ng gen nay se tnjc tiep gay ra nhang h6i chung roi loan thAn kinh c6 bieuhien lam sang giOng nhu benh tv kY Mang det bien clAu
1
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sCs
4-\
6' 01 "1 o, a " 4 9 ' ce \IP S
b Cl= 4 4 V s • e -V" ""k s •
tien da duqc tim thy tren cac gen inh hu6ng den
kh6p thin kinh nhu gen SHANK3 (SH3 and
multiple ankyrin repeat domains 3) (Gauthier et al.,
2009; Moessner et al., 2007) NLGN3 (Neuroligin 3)
va NLGN4X (Neuroginin 4, X-linked) (Jamain et
al., 2003; Laumonnier et al., 2004) Trong do,
nhung d6t bien tren gen SHANK3 duqc cho la yeu
to chit yeu hcm tat ca giy ra ph8 rOi loan tq kY hay
con goi la h6i chimg Phelan — McDermid (Durand
et al., 2007) Ben canh do, sq ph& trien cUa ceng
nghe giai ma town b6 he gen ngu6i ding viec tim ra
nhung bien the s6 lumg ban sao chep (copy
number variations — CNVs) da gifip tim ra duqc
nhung bien the di truyen giy inh hung 16n den
benh kY cling nhu khang dinh met cich chic
chin tam quan trong cua chirc 'tang khop thin kinh
d6i vai benh tr k9 (Autism Genome Project, 2007)
Cac nghien ceu sau de da tim ra nhung CNV ten
phirc he gen NLGN-NRXN-SHANK Ara hai gen !chop
thin kinh Mac nhu SynGAP va DLGAP (Berkel et
al., 2010; Marshall et al., 2008; Pinto et al., 2010)
Tuy nhien, cho den nay, tucmg quan giea kieu hinh
vi kieu gen dm benh nhin van chua duqc lim
sang to
Trong bii bio nay, chUng toi de cap den cac
phucmg phi!) sinh hoc phin tir de Oat hien (let
Wen gen giy benh de tit d6 c6 the chin dofin benh
nhanh hon (tong th6i gifip cac bac &I dua ra nhung
16i khuyen heti ich cling nhu phip
s dieu tri dung din
ANH HONG
Le Bic Viet et al
TInh hinh b?nh tv ky hi4n nay Tien the gi6i, nhung nghien ciru yr trtrac nam 1985
ve tS l I:41th tv lc* va nhung dieu kien lien quan cho ket qui 5 tru&ng hqp troll 1000 tre em dual
18 tuoi Te nhung nam 1980, so ca mac benh duqc chin doin thanh c8ng tang len vOi t6c d6 nhanh ch6ng Met Olin la do nhung tien 136 cua y hoc chin doin va chinh phli cling da diu to nhieu ham vac) Unit vqc y to dOC biet là nhung benh lien quan den thin kinh (Blumberg, 2013) Trung tam Kiem sat vi Phong ch6ng benh (CDC) 6 My da dua ra t9 le tre mac nhung rOi loan tkr ky tren town ciu hien nay dat mem 12 ca trong 1000 tre em (American Autism Centers, 2011) Tai My, ts, le tlr k9 tinh tlr nhung nam 1980 den nay di tang gip
den 10 lin, uorc tinh 1/110 tre em (1%) duqc chin
doin mic,benh Dieu nay a ding duqc giii thich bai loi song ngAy cang thqc dung tai My Ben canh my, Anh cling IA met mac co t9 le tq kjr dat muc cao (xip xi 1%) (Autism Society, 2006) Ngoai Anh vi My co ty le mac tlr k9 cao, benh nay cling co inh huerng tren khap cac qu6c gia tren the gi6i Tuy nhien, rat kh6 de xac dinh chinh xic tY le nay Posserud ding c6ng skr (Autism Society, 2010; Autism Speaks, 2008) da th6ng ke
deu tren khap cac Chau lqc (tre Chau Phi) dqa tren sq chin elan tkr kY 6 cac tre em song tren dit
nuac de (Autism Speaks, 2008; Posserud et al.,
2010) (Hlnh 1) Do ty 1(9 co the xiy ra dOng th&i
va a bi nham Ian vai nhieu benh khic ye mat thin kinh nen de tinh toan chinh xic tY le mac benh la met viec tucrng doi kh6 khan
Hinh 1 Tlnh hInh bOnh tit kjr tai mOt s6 quOc gia hen thO giai
Trang 3Tai Viet Nam, cho den nay van chua c6 met dieu
tra, thong ke chinh thirc ve benh to kSr Neu chieu
theo ti le cua Anh quec, Viet Nam hien c6 83 trien
dan thi c6 160.000 ngu&i to VS/ Ben canh do, theo so
lieu cita Be Thucmg binh vi Xa hei c6 khoang tir
5-7% tre em tan tit 6 dO tuoi clued 15, trong de tre em
to 1(9 va bai nao chiem khoang tren 40% Ngoai ra,
trong so nhung tre ducc chin doin xic djnh li to IcS,
trong giai doan ttl 2008 — 2011, chi Ichoing 12% so
tre duqc phit hien cic diu hieu cua berth truck 2
tuoi; 19,74% so tre duqc phit hien li do co giao chit
khong phai b8 mg hay 8ng bi; 56,58% tre duqc phit
hien benh nha diu hieu chim not (tre da han 2 thing
tuoi) Ben canh do, theo nghien cuu me hinh tan tit &
tre em cua Khoa Phuc hoi chirc nang Benh vien Nhi
Trung uang, giai doan 2000-2007, so lucmg tre duqc
chin doin va dieu trj to lcSe ngay cingsdeng; tre to k9
den khim nam 2007 tang gap 50 lan so vii nam
2000; s6 tre to IcS, den dieu tri nam 2007 tang gip 33
lan so yeti nam 2000 Xu the mac to lcSr tang nhanh tir
122% den 268% trong giai doan 2004-2007 so yin
nam 2000 Theo cic thong ke tir Berth vien Nhi deng
I, TP HO Chi Minh, nam 2000, Benh vien chi dieu trj
cho 2,tre bj to k9, thi sau 4 nam con se nay da li 170
tre, den nam 2008 con so nay tang gip gin 2 lan tirc
la 324 tre
Bieu hien lam sang binh ter 1[5,
6 benh to 1c9, rei loan phit trien he thin kinh
chinh la Neu hien lam sing tieu bieu nhit N6 bao
gem nhieu trieu chimg khic nhau & ngu&i benh, tip
trung lai ph6 rOi loan to icy (autism spectrum disorders
- ASD) Trong do, n6i, nhat chinh li so kern phit
trien toan din tre mac benh, dac biet IA kha nang sir
dung ngen nprei kern, chim biet n6i; ngai hoac khong
muen giao tiep van ngtr&i khic; tir do din den cic hoat
deng xa hei bj kim ham met cich tei da
DOi vii nhung hinh dOng sinh hoat hang ngiy, tre
thuting co xu htreing lam nhung viec lap di lap lai theo
bin nang ma khong chju ngei yen met ch6 hay con
goi la hien tuong tang deng (Lam and Aman, 2007)
Hien Wong nay lai bao gem nhieu bieu hien khic nhu
ngu&i benh hay c6 hinh dOng quay co tay, quay diu
hay c6 nhung hinh Ong c6 tinh bat buec vi du nhu
xep de chaff, bitp be,, 0 to thinh met hang ngang hoac
doc Nguy hiem nhat chinh la benh nhan lai hay to
lam minh bj thuong nhu: lay tay choc len mat, dm len
da, to danh vao tay, vao dau Met nghien cuv vao nam
2007 da bao cao ve hien wow nay vii ti le 30% benh
nhan c6 dau hieu rei loan to kk (Dominick et aL,
2007)
M6t van da nava la Ire mac benh thuong c6 khi 'tang di lai chim han nhieu so vii tre Ichic, thuong phii mit 2-3 num tuoi mai di lai binh thuong duqc Ngoai ra, kha tang lien lac bang mat cita tre thoc so kheng tot vi benh nhi thuong c6 thii de he( hung vii moi thir xung quanh
Nhiing yiu to gay benh b cap de di truyen hue Benh to 1c9, c6 nen tang di truyen rat manh, n6 Bong Op len den khoang 90% kha 'tang benh to Ic9 phit trien & tre em va thong thu&ng duqc chi ra bei
cic gen ttrcmg ung (Hallmayer et al., 2011) Mac di'
viy, so di truyen benh rat phirc tap vi khong re rang (Abrahams and Geschwind, 2008; Buxbaum, 2009) Nhiing nghien ciru ye nhung cap song sinh da cho thay so di truyen benh to 1c9 c6 xic suit la 0,7 vi dei vii phe roi loan to kS, len an 0,9 Dac biet doi yen nhang cap song sinh la con gii thi kith nang di truyen to IcS, gap tai 25 lin so vii ngu&i binh thuong (Geschwind, 2009) Tuy nhien, cho den nay, nhifmg det bien c6 nguy ca gay to ky vi 016 r6i loan tkr ky van chua duqc xic djnh het Nhung diet Wen nay c6 the là det bien don gen (det bien chi xiy ra tren met gen) hoac IA nhang bien dei bat thu&ng tren nhiem sic the (NST) Nhung det bien NST nay gay ra ntrOng hei chirng benh khic nhau lien quan den phis) rei loan to kjf (Abrahams and Geschwind, 2008) Nguyen nhan gay benh bit nguen tir nhi-mg hien the
so Itrong sao chep (copy number variations) tren gen qui djnh, nhung bien the nay c6 the li mat doan, lap doan, them doan, dio doan tren gen hoac NST (Cook and Scherer, 2008) Berth to Ic9 c6 tinh di truyen nhung Ichong chic chin c6 tinh ke filth Dieu de the hien & ch6: con cai mac benh tuy nhien be mg van c6 the hoan toan binh thu&ng, khoe manh duqc goi la ngu&i mang mam benh (Beaudet, 2007)
Thai gian gin day, met s6 gen vi NST c6 nguy ca gay ra to Ic9 vi phe rOi loan to k,S, da duqc cic nhi khoa hoc tim ra Nhung det bien vi bien doi bat thu&ng tren nhiing gen nay gay ra nhting hei chimg khicnhau, tang vii mOi loai phe red loan to Ic9 vi mei hei chirng duqc dat ten theo nha khoa hoc da phit hien ra n6: hei chirng
Asperger vii gen NLGN3 va NLGN4X (Jamain et al., 2003; Laumonnier., 2004); hei cluing Phelan-McDermid vii gen SHANK3 (Durand et al., 2007; Gauthier et al., 2009; Moessner et al.,
2007), hei chirng nay con co ten khac la hei chirng x6a NST 22q13 CA 3 gen nay deu c6 diem chung la anh htrang troc tiep den so phit trien cua trung tam than kinh
3
Trang 4Le Bic Viet et al
Gen SHANK3 ma h6a cho met loai protein lien
quan truc tiep den cac khap than kinh giau proline
Gen nay nam tren NST canh dai 22q13 Ve mat chat
nang, gen SHANK3 la mot thanh vien trop lien hQ
gen SHANK Cac protein SHANK deu bao gom nhieu
vOng (domain), la nhiing protein xoan hinh ,khan,
duqc sinh ra ki sau phin bao Chung ket tivc
tiep diem thy cam he thong can truyen than kinh, cac
kenh ion va nhang protein mang khac den actin
cytoskeleton va G-protein Protein SHANK kheng
nhthig ce chirc nang kiem soat to chac mit dO khap
than kil!' ma con c6 }chi nang tao phirc he receptor
khap thin kinh, phin tir tin hieu va protein lien quan
den to bao xuang c6 trong tity cOt song (Boeckers et
al., 2002; Naisbitt et aL, 1999) Trong do, protein
SHANK3 c6 the tao lien ket yeti to bao protein thin
kinh (Meyer et al., 2004) Do viy, trong so 3 gen
chirc nang anh huang den henh tu kSr ke tren, gen
SHANK3 duqc coi la nhin to ce anh huang manh me
nhit de giy ra pho rAi loan tv kS, a ngu&i benh Gen
khoang 60 kb, bao gOm 23 exon Trong de exon 23
co kich thuac dai nhat va eking vai Ire quan trong
trong viec *ay ra hOi chang x6a NST 22q13 - met
hOi chimg rat dac trung cua H) p roi loan to kjt
Gen NLGN3 nam tren NST X ma h6a cho
protein Neuroligin-3, la met thanh vien trong lien hQ
protein neuroligin trong nhOrn cac protein be mat
to bio thin kinh Neuroligin tham gia vao ciu tao va
dinh hinh nen trung tam he thong thin kinh Nhiing
bien the (mit, them, dao doan) tren gen nay di duqc
xac dinh, tuy nhien toan bO trinh tu doan gen cho den
nay yin chua duqc xac dinh chinh xac
Gen NLGN4X ma h6a cho protein Neuroligin-4,
X-link Protein nay din* thuOc hQ neuroligin nen cimg ca vai fro *An giOng nhu neuroligin-3 Gen
NLGN4X ding nam tren NST X, c6 kich thuac
Ichoang 5,5 Mb Khac vai gen NLGN3, hi4n nay, mai
chi c6 2 bien the duqc xac dinh tren gen NLGN4X
WO Men teen gen SHANK3 va hOi chfing x6a NST
22q13
Nhiing hien the tren gen SHANK3 hau hit la
mat met doan DNA Ian, do dO hien Urging nay con g9i la hpi chang xoa NST 22ti13 HOi ,chirng nay mang gin nhu dAy m9i diu hieu rOi loan dm benh to kS, nhu da neu a tren, do da gen nay duqc coi nhu nhin to chu ch8t trong viec giy benh tg Icy Trong do, dOt bien x6a toan be exon cuoi hinh thanh hei chung benh rat dien hinh cua hqi chirng Phelan-McDermid, ten g9i khac la hOi chung x6a NST 22q13 Hien tuqn* mit doan tren NST 22q13 bit nguon tir nhaing mat doan nucleotide, skr hoan
vi gen hoac su thay doi cau trfic anh huang den NST canh dai 22 Kich thuac doan gen bi x6a tren NST 22q13 thuang dao dOng trong Ichoing 100 kb den 9 Mb chia lam 3 loai da la: xoa met doan nho, xoa doan rat nh6 va xoa doan Ian Nhimg nghien ciru truac day da chi ra x6a doan nh6 giy ra pho roi loan dac trung cua benh tu kSt, x6a doan lon co
xu , huang giy ra nhang kieu hinh nghiem trQng nhit va x6a doan rat nh6 mang nhising diem ca ban cua hOi chang x6a NST 22q13 da dirge bao tir
tnrac (Moessner et al., 2007) Bonaglia cung tong
skr da liet ke duqc nhang mit doan tren NST
22q13 tren 42 benh nhan nghien ciru (Bonaglia et
al., 2011) (Bang 1)
Bang 1 Danh sach nhCrng mat doan m6iduvc tim thay tren NST 22q13
Trang 512 NO, aCGH Del(22)(q13.3) X6a nucleotide tai exon cuoi 1.08 Mb China xac dinh
13 NO, Phan tich NST Del(22)(q13.31) X6a nucleotide tai exon cuoi 5.8 Mb China xac dinh
14 Nam Phan tich NST Del(22)(q13.2) X6a nucleotide tai exon cuoi 7.6 Mb Cha me
di truyen
15 NO' FISH Del(22)(q13.31) X6a nucleotide tai exon cuoi 4.7 Mb Chu,a xac dinh
16 Nam FISH Del(22)(q13) X6a nucleotide tai exon cuoi 3.7 Mb Chive xac dinh
17 NO' Phan tich NST Del(22)q(13.2q1 X6a nucleotide tai exon cuoi 7.2 Mb Cha me
3.3)
18 NCr FISH Del(22)(q13.31) X6a nucleotide tai exon cu6i 4.7 Mb Mg
19 NO, FISH Del(22)(q13.32) X6a nucleotide tai exon cuoi 1.9 Mb Mg
20 Nam aCGH Del(22)(q13.31) X6a nucleotide tai exon cu6i 3.4 Mb Cha me
22 NO, aCGH Del(22)(q13.32) X6a nucleotide tai exon cu6i 1.8 Mb Cha me
23 NCr aCGH Del(22)(q13.31) X6a nucleotide tai exon cuoi 3.4 Mb Cha mg
24 Nam aCGH, MLPA Del(22)(q13.33) X6a nucleotide tai exon cuoi -122 Kb Cha me
25 NO' aCGH Del(22)(q13.33) X6a nucleotide tai exon cuoi -122 Kb Cha me
26 Nam FISH Del(22)(q13.31) X6a nucleotide tai exon cuoi 4.4 Mb Cha me
27 Nam FISH Del(22)(q13.31) X6a nucleotide tai exon cuoi -4 Mb Cha me
28 NCr Phan tich NST Del(22)(q13.2) X6a nucleotide tai exon cuoi 9.0 Mb Cha me
29 Nam aCGH Del(22)(q13) X6a nucleotide tai exon cuoi 122 Kb Cha me
30 NCr Phan tich NST Del(22)(q13.2q1 X6a nucleotide tai exon cuoi 7.4 Mb Me
3.3)
31 NO' Phan tich NST Del(22)(q13.31q X6a nucleotide tai exon cuoi 5.8 Mb Cha mg
13.3)
32 NO' aCGH Del(22)(q 13.3q 1 X6a nucleotide & giO,a NST -74 Kb Cha me
3.3)
3.3)
X6a nucleotide b giCya NST -44 Kb Cha mg
34 Nam aCGH Del(22)(q13.3q1 X6a nucleotide & giDa NST -18 Kb Chiya xac dinh
3.3)
35 NCr aCGH Del(22)(q13.3q1 X6a nucleotide 6, giCra NST -27 Kb Chu,a xac dinh
3.3)
36 Nam aCGH Del(22)(q13.3q1 X6a nucleotide a gift NST -39 Kb Chiya xac dinh
3.3)
37 NCr Phan tich NST Del(22)(q13.32) Ring 22 2.16 Mb Cha me
38 NO' Phan tich NST Del(22)(q13.33) Ring 22 1.2 Mb Chu,a xac dinh
41 Nam Phan tich NST Del(22)(q13.31) Ring 22 3.2 Mb Cha me
42 Nam Phan tich NST Del(22)(q13.32) Ring 22 2.04 Mb Cha me
CAC PHUONG PHAP CHAN DOAN 0 CAP DO
PHAN TU, TE BAO
Nhu di nal u tren, nhang d6t bi6n hay nhang bien
the so luting sao chep tren nhirng gen chirc nang lien
quan den he thong thin kinh anh huang den benh to kY
hau het la nhang mat doan, lip doan hoic dao doan Do
d6, de Oat hien &roc nhirrig bat thuang nay, doi hoi
phai can Ai) dung ca flitting phuong phap sinh hoc phan
to ciing nhu sinh hoc to bao Nhang phtrang phap hien dai va dang duac clang ph6 bien nhat hien nay la array comparative genomic hybridization (aCGH), fluorescence in situ hybridization (FISH) Ben canh do, multiplex ligation probe amplification (MLPA) la in6t phuang Olaf) ding rat hiTru ich &roc dung,nham xac nhan lai nhang mat doan hoc d6t bien diem di tim
5
Trang 6Le Bic Viet et al
they bang cac phucmg phap traac do Ngoai 3 phucmg
phap hay clang den a tren, phuong phap giai trinh iv the
he mai di buac dau duqc img dung nha lcha nang doc
duqc trinh to met doan DNA caa ne
Phtrang phip array comparative genomic
hybridization (aCGH)
aCGH la met phuong phap duqc sir dung de xac
djnh nhen bien the trong phien ban sao chep caa
genome nhu them hoac mat NST hay met phan NST
Ve nguyen li tien hash phuong phap aCGH, man dua
vao thi nghiem lute phai gem it !that 2 Mau, do la man
'dem tra (test) va mau doi chimg (control) Nheng mau
nay la DNA tong so di duqc tach chiet tir trtrac do va
hoin toan dO dieu Ici'e'n ve de tinh sach Mat khac,
phuong phap doi hoi nhang matt do dac hieu cho
nheng (loan DNA nghi ng6 bj x6a hoac chen them
nucleotide Mau de nay la nheng doan oligonucleotide
co kich thuac tir 20-85 nucleotide Cuei cling, yeu to
Ichong kern phan quan tong khac caa aCGH la nheng
tin hieu lai (hybridization signals) Tin hien lai nay la
nheng mau huSmh quang duqc nhuem vao man lam
tra, trong !chi mau doi chimg duqc nhuem vai met loai
mau dac trung khac Trong phucmg phap aCGH, tin
hieu lai nay chinh la yeo to quan tong de nhan biet c6
hay Ichong nheng su bat thuang trong gen/doan DNA
ma minh dang nghien cau
Dua vao phucmg phi') nay, 10 dot bien va 14 (let
bien mit doan tren NST 22q13 Ian lugt di phat hien
thay tren cac nghien ciru cita Bonaglia va Soorya cling
cac cong su (Bonaglia et al., 2011; Soorya et al., 2013)
Phtroug phi') gild trinh ttr the he mai
Giai trinh to the he mai (illumina dye sequencing)
la met ki thuat ducc sir dung a xac djnh 4 loai cac
baza nits tren doan DNA dua ten nhimg mau quknh
dac hieu cho mOi loai bazo nits Su tien be cua
phuong phap nay the hien 6 the n6 c6 the xac djnh
duqc trinh to a ca nheng 'yang khe doe va nheng trinh
to lap lai Trong nghien ciru oh Chaste ding cling
cong stir, phuong phap giai trinh ttr mai tren may
illumina di buac dau duqc img dung de phat hien 5
bien the tren met se gen va NST c6 lcha nang gay phe
rei loan to kk (Chaster and Leboyer, 2012)
Phuong phdp MLPA
icy thu4t MLPA (multiplex ligation probe
amplification) la met ki thuat sir dung nheng man del
(probe) dac hien duqc khuich dai nh6 phan img PCR
nham sang loc nhimg (let bien thuong gap tren
nheng gen chirc nang gay benh di truyen Be Kit
MLPA duqc thucrng mai h6a tir cong ty MRC
Holland, Amsterdam, Ha Lan Vai tro chinh caa MLPA trong nghien benh ttr Ick la nham kiem tra xac nh4n lai ket (let bien mit 'Joan hoac dot bien diem di duqc tim thay nha phuong phip cac phucrng phap phan tich NST hoac giai trinh AL Cho den nay,
di co tong cong 37 mall de duqc sir dung cho NST 22q13 va 4 trong so de dac hien cho gen SHANK3
Plurong phap FISH FISH (lai huknh quang trong to bao) la met ki thuat di truyen hoc to bao duqc cac nha nghien ciru y sinh hoc phat then vao dau nheng nam 1980 Phuang phap nay clung de phat hien va khoanh vimg cac diem mat hoac ellen them nucleotide 6 cac trinh
tv DNA trong NST FISH sir dung nheng mau do huknh quang gan vao nhimg phan mong muen cua NST DO phat hien nhang yang gin dm mau do huknh quang len NST, kinh hien vi huknh quang can duqc sir dung FISH thuang duqc sir dung de tim ra nhang diem dac tnmg trong DNA nham dua ra nheng 16i khuyen di truyen, xac djnh loai va thuoc mai Doi vai phuong phap nay, met mau do can duqc thiet ke Mau de phai c6 kich thuac du km de lai met cach dac hieu vai DNA dich nhung cling khong duqc qua Ian se rat de gay kim yam qua trinh lai Mau de duqc gan duOi truc fiep vai huknh quang, can vai DNA dich la Idling the
Thuc te, FISH la phuong phap di truyen hoc to bao ducc biet den nhieu nhat trong viec phat hien nhemg bat thuang tren NST (Durand et al., 2007) TOng cong di c6 28 OA bien mit doan di tim thay trong nhang nghien ciru cua Bonaglia va Soorya ding cong su ve benh to Ick (Bonaglia et al., 2011; Soorya et al., 2013)
TIXONG QUAN GICJA KIEU ILINH VA KIEU GEN
Met trong nheng yin de quan tong nhtmg chua duqc giai quyet ki cang la viec am hieu nheng mei ttrcmg quan gift bien the di truyen va kieu hinh benh
to kk Gia thuyet dau tien li giai tinh Ichong den nhat ye kieu hinh cua benh trong suet qua trinh phat trien gay ra su cham phat trien co the 6 ngeri benh MOt gia thuyet khac la nguyen nhan gay benh den tir
ca nheng bien the hiem va thuang gap Mac du cac nghien can co lien quan trtrac day van chua dua ra duqc nheng bang chirng re rang ye nguyen nhan c6 nguOn gec tir nhtmg hien the ha?, gap 6 benh tu.kk, nhung cac phan tich gan day ye nheng bien the di truyen lien quan den phe roi loan to Ick di dua ra gqi
k rang ca nheng bien the hiem hay thuang gap deu
Trang 7c6 the gay ra phO rOi loan tv ky do sir lign loan cfra
mang ltrai than kinh (Ben-David and Shifman,
2012) Gia thuyet cuOi cling, khong lien quan den hai
gia thuyet tru6c do, la nguyen nhan bat nguan tir
nhung yeu to mai truing lam thay doi kieu hinh
SU' TUONG TAC GIUA YEU TO DI TRUYEN
VA MOI TRUONG (GxE)
Nheng sir khong ang nhAt ve met di truyen c6
the duqc ly giai la do flirting nghien ciru lien quan
den benh tv ky van con kha it Tuy nhien, nheng ket
qua nay con c6 the duqc lam sang to drra tren khung
hinh mau twang tic GxE (D'Amelio et al., 2005)
Ben canh nhung nguyen nhan ye di truyen dA &Km
neu a tren, nheng tranh cal xung quanh nguyen nhan
bat nguon tra moi truing not len nhu benh nhan c6
tiep xtic vai nhung loai kim loai nAng c6 thu8c
tna sau, thuoc diet co, benh truyen nhiem do virus
hay nhung hoa chat dOC hai thai ra moi tnnang
MAc du Meng ket qua ban du thu (URN la rat
dang khich le, nhtrng gia dinh va benh nhan c6 lien
quan den benh tv ky van clura duqc ma rOng nghien
dm den sir Wang tic GxE M'et trong nhung van de
chinh trong hinang nghien ciru nay do la kha nang de
phat hien nhung twang tic GxE thuang it kha thi hon
kha nang phat hien nhung anh huong rieng re dr di
truyen hay moi truing Nheng nghien ciru ye twang
tic GxE a trong nhung 1:18i cheng kilt loan thin kinh
khac nhau dang din bi lang xwingdo thieu di nhung
ket qua tich cuc (Duncan and Keller, 2011) Tuy
nhien, nhung ket qua nghien ciru nay van can thiet
bai chfing glut) chung to hieu hon ve tinh khong lien
trong nhirng nghien ciru ttr twac den nay va tir
Q6 Qua an nhung gqi him ich ve phuang phip
ngin chAn benh tir sarn
CuAi ding, nhung nghien ciru tiep theo ve moi
twang quan giea nhung bien the hiem gAp c6 lien
quan den pho rOi loan tit ky va nhung yeu to moi
twang tren nhung benh nhan mang cfic dOt bien da
duqc xic dinh c6 the se rat hen ich Tuy nhien, de
thuc hien duqc dieu do cling khong he a ding do ,s6
ltrqng ngtnai mang mam benh kh6ng nhieu
'CET LUAN
Cho den nay, nhO sir phat trien cita khoa hQc
cOng nghe, dAc biet la linh vuc di truyen hQc da dua
den nheng quan niem mai ye ca the phan flit va to
bao gay ra benh tu Icy NO khong chi din gian la do
nhung yeu to moi truing ben ngoai tic amg, ma con
c6 the do ca nhung rOi loan chric nAng gen Nhieu cau hal mai se not len, bao gem vai tra cita nhung bien the hay gAp va sir tuong quan gift kieu hinh va kieu gen oh benh Cuoi ding nhung cling khong kern phan quan trong, str am hieu ye su tuang tic gift nh(tng yen to di truyen va hoan canh moi tnnang
la rat can thiet doi vai nghien tiro benh li cita hr ky, tuy nhien de di sau vao nghien ciru su Wang tic nay can doi hoi mot Wong mau benh lin va thai gian nghien ctru lau dii
Uri cam an: Cong trinh nghien citu nay duqc Myr hien bang sy ho try kink phi dm de tai cap ca sd Vien Nghien ctiu he gen, Vien Han lam Khoa hQc va Cling nghe Viet Nam
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Trang 9GENETIC FACTORS CAUSING AUTISM IN CHILDREN: STATUS AND DIAGNOSIS METHODS
Le Bac Viet, Nong Van Hai, Nguyen Huy Hoang*
Institute of Genome Research, Vietnam Academy of Science and Technology
SUMMARY
In the modem life, autism is becoming more and more popular in society, especially children Originally,
it was believed that the major cause of this disease is due to environmental factors such as lacking care of parents or teaching responsible people Therefore, children patients are delayed in entire development of languages, communication and social activities In recent years, studies of autism have been obtained a great breakthrough when scientists found out genes getting involved in this disease due to mutagenesis Thus, a consideration was brought out that autism may be well a heritable disease from parents Among related genes,
the SHANK3 gene is the main contribution factor, beside the NLGN3 gene, NLGN4X gene Array
comparative genomic hybridization (aCGH) and floumescence in situ hybridization (FISH) are two main methods applied for autism-related genes/chromosomes analysis Moreover, multiplex ligation probe amplification (MLPA) technique is used to confirm results obtained by two methods above After diagnosising genetic disorders, some treatment therapies should be implemented in order to encourage autism patients be positive in communicating, social activities and recognizing everything around However, up to now, two issues which are still debatable and unsolvable, are the relationships between phenotype-genoype and the interactions between genetic factors and environmental backgrounds In the near future, if these wonders are answered, there will be a significant step in prevention and treatment of autism
Keywords: aCGH, autism, FISH, genetic, MLPA, SHANK3 gene
* Author for correspondence: E-mail: nhhoangaigrac.vn
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