. Author manuscript; available in PMC: 2018 Mar 22.

Published in final edited form as: Eur Arch Psychiatry Clin Neurosci. 2017 May 29;268(3):301–316. doi: 10.1007/s00406-017-0808-8

Table 2.

Overview of investigated candidate genes previously implicated in TS, OCD, or ASD

TS neurotransmitter-related candidate genes	# of tSNPs	# of tSNPs excluded following QC^a	CHR	Neurotransmitter pathway	Function	Sample size reference study	Reference
DRD2	14		11	Dopamine	Dopamine receptor	147 TS / 314 controls	[3]
HDC	11		15	Histamine	Histamine synthesis	520 TS families	[17]
MAO-A	9	1	X	Serotonin (5-HT), dopamine	Degradation of dopamine and 5-HT	110 TS parent-child trios	[4]
SLC6A3/DAT1	21	3	5	Dopamine	Dopamine transporter	266 Cases / 236 controls	[37]
TPH2	19		12	Serotonin (5-HT)	5-HT synthesis	149 TS / 125 controls	[42]

Candidate genes implicated in related disorders

GABRA2	14		4	GABA	GABA receptor	470 Autism families	[14]
SLC1A1	52		9	Glutamate	Glutamate transporter	377 OCD families	[15]

Newly investigated candidate gene

HRH3	8	2	20	Histamine	Histamine receptor

TS, Tourette syndrome; OCD, obsessive-compulsive disorder; ASD, autism spectrum disorder; tSNPs, tagging SNPs; QC, quality check; CHR, chromosome; DRD2, dopamine receptor D2; HDC, l-histidine decarboxylase; MAO-A, monoamine oxidase-A; SLC6A3/DAT1, solute carrier family 6 / dopamine transporter; TPH2, tryptophan hydroxylase 2; GABRA2, GABA-A receptor, alpha 2; SLC1A1, solute carrier family 1 member 1, glutamate transporter; HRH3, histamine receptor H3.

SNPs were excluded following standard quality control checks in PLINK V1.07 using the recommended parameters published in [29, 30].