[Etiology of nonspecific chronic cough in children and relationship between TRPV1 gene polymorphisms and nonspecific chronic cough].
OBJECTIVE
To explore the causes of nonspecific chronic cough in children and relationship between transient receptor potential vanilloid 1 (TRPV1) gene polymorphisms and nonspecific chronic cough.


METHODS
A total of 195 children with chronic cough were followed up half a month, one month and three months after their first visit to hospital. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to examine polymorphisms of the TRPV1 gene in the children. A total of 205 healthy or surgical children without chronic cough served as the control group.


RESULTS
The etiologic distribution of the 195 children with chronic cough was as follows: 96 (49.2%) cases of cough variant asthma (CVA), 48 (24.6%) cases of CVA complicated by upper airway cough syndrome (UACS), 34 (17.4%) cases of post-infectious cough, and 17 (8.7%) cases of UACS. Three genotypes were identified in both groups at positions rs222747 (CC, GC and GG), rs222748 (CC, TC and TT) and rs8065080 (CC, TC and TT). The frequencies of genotype and allele at position rs222747 did not accord with the law of Hardy-Weinberg. There was no significant difference in frequencies of genotype and allele at positions rs222748 and rs8065080 between the two groups.


CONCLUSIONS
CVA, UACS and post-infectious cough are common causes of nonspecific chronic cough in children. TRPV1 gene polymorphisms at positions rs222748 and rs8065080 may be unrelated to nonspecific chronic cough in children.
Ministry of Education Key Laboratory of Child Development and Disorders, Key Laboratory of Pediatrics in Chongqing, Chongqing 400014, China.
Xiao-Ning
XN
Zhang
Juan
J
Yang
Zheng-Xiu
ZX
Luo
Jian
J
Luo
Luo
L
Ren
Bo
B
Li
Kun-Hua
KH
Chen
Zhou
Z
Fu
Quan
Q
Lu
En-Mei
EM
Liu
D000293:Adolescent; D000483:Alleles; D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease; D003371:Cough / Q000209:etiology / Q000235:genetics*; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D008297:Male; D011110:Polymorphism, Genetic; D050916:TRPV Cation Channels / Q000235:genetics*
D050916:TRPV Cation Channels; C494482:TRPV1 protein, human