Table 2.

Overview of genetic association studies in functional dyspepsia

Protein (gene)	Polymorphism	Finding	Ref.
TLR-2	(192-174)del	Protective for Helicobacter pylori-infected patients	[43]
SERT	SS variant	No association	[45]
5-HT1A	-Pro16Leu	No association	[46,47]
5-HT2A	-1438 G/A	No association	[46,47]
HTR3A	C178T	No association	[46,47]
GNB3	C825T	Risk factor	[48-50]
GNB3	CT and TT carriers	Risk factor	[48-50]
GNB3	C825T	Risk factor for PDS	[48-50]
GNB3	CC and TT carriers	Risk factor for PDS	[48-50]
GNB3	C825T	Risk factor	[48-50]
GNB3	CC carriers	Risk factor	[48-50]
GNB3	C825T	Risk factor for EPS	[50]
GNB3	TT carriers	Risk factor for EPS	[50]
Presynaptic inhibitory α2A and α2C adrenoceptor	-1291 C>G (α2A) and -del 1322-325 (α2A)	No association	[46]
Fatty acid amide hydrolase	C385A	No association	[51]
TRPV1	G315C	Risk factor	[52]
Na (V) 1.8	SCN10A	Protective	[53]
Na (V) 1.8	3218CC	Protective	[53]

PDS: Post discharge surveillance; EPS: Encapsulating peritoneal sclerosis; TLR: Toll-like receptor; TRPV: Transient receptor potential vanilloid.