Association of serotonin transporter polymorphisms with responsiveness to adrenocorticotropic hormone in infantile spasm

Xiu-Yu Shi, Li-Ping Zou, Guang Yang, Ying-Xue Ding, Bing He, Yan-Hong Sun, Fei-Yong Jia

Beijing, China

Author Affiliations: Department of Pediatrics, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, China (Shi XY, Zou LP, Yang G); Department of Pediatrics, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China (Ding YX); Division of Matrix Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden (He B); Department of Pediatrics, Cangzhou Central Hospital, Cangzhou 061001, China (Sun YH); Department of Pediatrics, First Hospital of Jilin University, Changchun 130021, China (Jia FY)

Corresponding Author: Li-Ping Zou, MD, Department of Pediatrics, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, China (Tel: +86-10-66939770; Fax: +86-10-66939770; Email: zouliping21@hotmail.com).

doi: 10.1007/s12519-013-0420-6

Background: Serotonin or 5-hydroxytryptamine (5-HT) is an important neurotransmitter in the central nervous system. The serotonin transporter (5-HTT) is a key regulator of the level of serotonergic neurotransmission. In the present study, the contribution of 5-HTT polymorphisms to the risk of infantile spasm (IS) and the responsiveness to adrenocorticotropic hormone (ACTH) were investigated.

Methods: Two functional polymorphisms, the 44-bp insertion-deletion polymorphism in the promoter region (5-HTTLPR) and the variable number tandem repeat in the second intron (5-HTTVNTR), were genotyped in a Chinese case-control study involving 112 patients with IS and 120 controls.

Results: Genotyping yielded valid data in 111 patients and 118 controls for 5-HTTLPR and 110 patients and 118 controls for 5-HTTVNTR. The polymorphisms were not found to have an allelic or genotypic association with IS. However, responsiveness to ACTH was higher in patients who were homozygous for L (91%) than in those with S/L (56%) or S/S (60%) (P=0.017). Haplotype analysis did not improve the observed association.

Conclusions: The results suggest that the 5-HTTLPR genotype may influence the responsiveness to ACTH. This interpretation deserves further study.

Key words: genetic predisposition; infantile spasms; polymorphisms; serotonin transporter

World J Pediatr 2013;9(3):251-255