[Detection and related analysis to chromosome 22q11 microdeletion in patients with congenital heart diseases].
OBJECTIVE
To ascertain 5 short tandem repeat (STR) markers as qualified tools for detecting chromosome 22q11 deletion and to understand the prevalence and clinical importance of the deletions in patients with congenital heart diseases (CHD) from Chinese Han population.


METHODS
The authors selected 5 new tetranucleotide repeat markers, 22D_4_1, 22D_4_2, 22D_4_3, 22D_4_4 and D22S873 located in the proximal region of chromosome 22q11 deletion. One hundred and sixty-three unselected CHD patients and their unaffected parents were analyzed by genotyping of these new tetranucleotide STR markers to detect 22q11 deletion. With fluorescence in situ hybridization (FISH, LSI dual color DNA probe), the deletion status was confirmed in all patients with deletions and some patients without deletions.


RESULTS
The heterozygosity of these STR markers in normal population was more than 0.7, except for 22D_4_1 and 22D_4_2 that were 0.65 and 0.52 respectively. Twelve cases of 163 CHD patients (7.36%) had the deletions at chromosome 22q11. The deletions were confirmed in 9 of 12 patients by FISH, except for 2 cases who had unique nested deletion and 1 case who had nested distal deletion. One hundred and ten patients were associated with ventricular septal defect (VSD); and 9 (8.18%) of these cases had microdeletion. Twenty-one patients were associated with tetralogy of Fallot (TOF); and 3 (14.3%) of these cases had microdeletion.


CONCLUSIONS
This study demonstrated that genotyping of 5 STR markers was a useful mean of detecting 22q11 microdeletion in clinical diagnosis owing to its rapid experimental procedure, cost effectiveness and high resolution. 22q11 deletion was common in CHD patients, particularly in VSD and TOF patients, from Chinese Han population.
Xu
Zheng-feng
ZF
Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, 210008 PR China. njxzf@hotmail.com
Yi
Long
L
Mo
Xu-ming
XM
Hu
Yali
Y
Wang
Dong-jin
DJ
Zhu
Rui-fang
RF
Jiang
Yong-zhong
YZ
Wu
Xing
X
Wu
Zhong
Z
Shen
Li
L
Zhang
Ying
Y
Zhong
Xiao-ling
XL
D002872:Chromosome Deletion; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics*; D006330:Heart Defects, Congenital / Q000175:diagnosis / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D018895:Microsatellite Repeats / Q000235:genetics; D016133:Polymerase Chain Reaction