[Patients suffered from enlarged vestibular aqueduct syndrome in Chifeng deaf and dumb school detected by Pendred's syndrome gene hot spot mutation screening].
OBJECTIVE
To investigate the incidence of hot spot mutation of PDS gene by genetic screening testing method in Chifeng City, Inner Mongolia. The feasibility and effectiveness of genetic screening method in finding enlarged vestibular aqueduct syndrome were confirmed by temporal bone CT scan.


METHODS
DNA were extracted from peripheral blood of 141 students of Chifeng Deaf and Dumb school. PDS IVS7-2 A-G mutation, the most common PDS mutation in Chinese population, was analyzed by direct sequencing for PDS exon 7, exon 8 with intron 7. The individuals found with homozygous or heterozygous PDS IVS7-2 A-G mutation were given further temporal CT scan, ultrasound scan of thyroid and thyroid hormone assays. The results of PDS genetic screening and temporal bone CT scan were compared with each other.


RESULTS
The sequencing results revealed twenty cases carrying PDS IVS7-2 A-G mutation, of whom nine cases were homozygous mutation and eleven cases were heterozygous mutation. Eighteen cases underwent temporal bone CT scan except two cases that left the school due to other health problem. Sixteen cases were confirmed to be enlarged vestibular aqueduct syndrome (EVAS) by CT scan and the shape and function of thyroid were clinically normal by ultrasound scan of thyroid and thyroid hormone assays, respectively.


CONCLUSIONS
The patients suffered from EVAS can be diagnosed by the screening for the PDS hot spot mutation which has unique advantage in epidemiologic study in large scale deaf population. The preliminary data of this study suggested relatively high incidence of EVAS in Chifeng area.
Dai
Pu
P
Department of Otorhinolaryngology Head and Neck Surgery, General Hospital of Chinese People's Liberation Army, Beijing 100853, China.
Zhu
Xiu-Hui
XH
Yuan
Yong-Yi
YY
Zhu
Qing-Wen
QW
Teng
Guo-Chun
GC
Zhang
Xin
X
Liu
Li-Xian
LX
Wang
Jia-Ling
JL
Feng
Bo
B
Zhai
Suo-Qiang
SQ
Kang
Dong-Yang
DY
Liu
Xin
X
Huang
De-Liang
DL
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002681:China; D005260:Female; D005820:Genetic Testing; D034381:Hearing Loss / Q000235:genetics*; D006801:Humans; D026901:Membrane Transport Proteins / Q000235:genetics*; D017354:Point Mutation; D000076988:Sulfate Transporters; D013577:Syndrome; D014723:Vestibular Aqueduct / Q000473:pathology*; D015837:Vestibular Diseases / Q000235:genetics*; D055815:Young Adult
D026901:Membrane Transport Proteins; C085609:SLC26A4 protein, human; D000076988:Sulfate Transporters