Understanding DTDS: A Medical & Scientific Glossary
Medical and scientific language can be overwhelming—especially when your family is navigating a rare genetic disorder like Dopamine Transporter Deficiency Syndrome (DTDS).
Terms such as dystonia, dopamine transporter, pathogenic variant, lumbar puncture, neurotransmitter, gene therapy, and natural history study may become part of everyday conversations with doctors, therapists, researchers, and other families. But understanding what these terms mean can make those conversations easier to follow and help families feel more confident asking questions.
The DTDS Foundation created Understanding DTDS: A Medical & Scientific Glossary as a practical reference for families, healthcare professionals, therapists, researchers, educators, and others who want to better understand the language surrounding Dopamine Transporter Deficiency Syndrome (DTDS).
What is DTDS?
Dopamine Transporter Deficiency Syndrome (DTDS) is an ultra-rare genetic disorder caused by disease-causing variants in both copies of the SLC6A3 gene. SLC6A3 provides instructions for making the dopamine transporter, a protein that helps regulate dopamine signaling in the brain.
DTDS primarily affects the nervous system and dopamine pathways and can cause a range of movement, developmental, and other neurological differences. Commonly described features include dystonia, abnormal muscle tone, bradykinesia, dyskinesia, and other movement difficulties. The way DTDS affects an individual can vary considerably.
Because DTDS is so rare, families may encounter unfamiliar terminology across many areas of care and research. This glossary brings many of those terms together in one place.
What is included in the DTDS glossary?
The glossary includes medical, genetic, neurological, therapeutic, research, and supportive-care terminology relevant to DTDS.
Entries include terms related to:
DTDS and dopamine biology, including DAT, dopamine, neurotransmitters, synapses, and dopamine transporter deficiency
Movement and neurological symptoms, including dystonia, dyskinesia, bradykinesia, rigidity, hypotonia, hypertonia, spasticity, tremor, chorea, and ataxia
Genetics and diagnosis, including SLC6A3, pathogenic variants, variants of uncertain significance (VUS), genetic testing, exome sequencing, and whole genome sequencing
Medical testing and biomarkers, including cerebrospinal fluid (CSF), lumbar puncture, MRI, EEG, and biomarkers
Therapies and medications, including physical therapy, occupational therapy, speech-language therapy, baclofen, levodopa, tetrabenazine, and botulinum toxin
Feeding, respiratory, and supportive care, including aspiration, dysphagia, enteral feeding, airway clearance, respiratory therapy, and supportive care
Assistive technology and mobility, including augmentative and alternative communication (AAC), gait trainers, orthotics, standers, wheelchair seating, and durable medical equipment
Research terminology, including clinical trials, natural history studies, patient registries, biobanks, biosamples, cell lines, RNA sequencing, gene therapy, and drug repurposing
Long-term and multidisciplinary care, including scoliosis, hip dysplasia, palliative care, quality of life, and multidisciplinary care
Each entry provides a straightforward definition along with an explanation of why the term matters in DTDS.
Why create a DTDS-specific glossary?
Many medical glossaries explain a term in general but do not explain how it relates to Dopamine Transporter Deficiency Syndrome. For families affected by DTDS, that distinction matters.
A term such as dystonia has a general neurological definition, but families may also need to understand how dystonia relates to DTDS. Similarly, terms such as pathogenic variant, biomarker, lumbar puncture, or gene therapy can have very different significance depending on the context in which they are being discussed.
This glossary was designed to provide that additional context while keeping definitions understandable and useful for people who do not have a medical or scientific background.
Who is the glossary for?
This DTDS glossary may be useful for:
Individuals and families affected by DTDS
Newly diagnosed families learning DTDS terminology
Neurologists and movement disorder specialists
Geneticists and genetic counselors
Physical, occupational, and speech-language therapists
Other healthcare professionals involved in DTDS care
Researchers studying DTDS, SLC6A3, or related neurotransmitter disorders
Educators and school professionals supporting individuals with DTDS
Advocates and organizations working in rare disease
It can be used as a starting point when encountering an unfamiliar term, preparing for a medical appointment, reading research, or discussing DTDS with a healthcare professional.
A resource that can grow with DTDS research
DTDS is an ultra-rare disorder, with approximately 50 documented cases worldwide. As research continues, our understanding of the condition will continue to develop.
New information about DTDS diagnosis, biomarkers, natural history, treatment approaches, gene therapy, and other areas of research may change how certain terms are understood or used. This glossary is intended to be a living educational resource that can be updated as knowledge advances.
The current edition is Version 1.0, published September 2026.
Download the DTDS Glossary
The complete Understanding DTDS: A Medical & Scientific Glossary is available as a free downloadable PDF.
We encourage families, healthcare professionals, researchers, educators, and advocates to share this resource with others who may find it useful.
About the DTDS Foundation
The DTDS Foundation is a nonprofit organization dedicated to supporting individuals and families affected by Dopamine Transporter Deficiency Syndrome, advancing awareness and understanding of this ultra-rare disorder, and supporting research toward better diagnosis, treatment, and ultimately a cure.
The Foundation connects DTDS families and researchers around the world, shares knowledge and resources, supports research efforts, and brings the patient and family perspective to the DTDS community.
Learn more about DTDS and the DTDS Foundation here.
This glossary is provided for educational and informational purposes only. It is not intended to replace medical advice, diagnosis, or treatment from a qualified healthcare professional. Medical information and research can change as knowledge advances. Always consult an appropriate healthcare professional regarding individual medical questions or decisions.
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