Diagnosis of SLC6A3-negative DTDS is established in a proband via molecular genetic testing, looking for biallelic (i.e. homozygous or compound heterozygous) pathogenic SLC6A3 variants. DTDS-positive patients are further identified by matching their genetic testing results with known characteristic clinical, laboratory, and imaging findings. To date, another potential diagnostic tool is neurotransmitter analysis of patient cerebrospinal fluid. All individuals tested with classical early-onset, SLC6A3-related DTDS display raised homovanillic acid (HVA) levels with normal 5-hydroxyindoleacetic acid (5-HIAA, a serotonin metabolite) levels. DTDS patients demonstrate a HVA:5-HIAA ratio of 5.0-13.0, above the normal range of 1.0-4.0. In addition, the patients have normal pterin profiles. Mutant constructs of human<unk><unk>  can be used for in vitro functional analysis of any particular mutant's<unk>  uptake and cocaine-analogue binding.
Dopamine transporter deficiency syndrome
Gerstmann syndrome
Scheie syndrome
Dopamine beta hydroxylase deficiency
Ohtahara syndrome
Pallister–Killian syndrome
Dopamine dysregulation syndrome
Gerstmann–Sträussler–Scheinker syndrome