SLC6A1 Europe

Research and Support Alliance (SERSA)

We are a European alliance of SLC6A1 patient organisations, working with researchers, clinicians and partners to advance research and improve the lives of people affected by SLC6A1-related neurodevelopmental disorder (SLC6A1-NDD) and their families.

WE STAND BESIDE EVERY FAMILY

We work to ensure that no family faces
SLC6A1-NDD alone.

WE SHARE TRUSTED KNOWLEDGE

We share reliable information with families, healthcare professionals and partners.

WE SUPPORT RESEARCHERS

We support SLC6A1 research and strengthen collaboration between researchers.

WE COLLABORATE WITH INDUSTRY

We support therapeutic development through access to patient expertise, data and biobank resources.

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What is SLC6A1-NDD?

SLC6A1-related neurodevelopmental disorder is a rare genetic condition estimated to occur in approximately 1 in 38,000 live births.

The SLC6A1 gene encodes a protein called GAT-1, which is located mainly in the membranes of nerve terminals of GABAergic neurons (neurons that use GABA as a neurotransmitter), and also in astrocytes. GAT-1 is responsible for the reuptake of GABA (gamma-aminobutyric acid).

Disease-causing variants in the SLC6A1 gene can impair GAT-1 function.

This can lead to developmental delay, intellectual disability, delayed or absent speech, epilepsy (particularly absence, myoclonic and atonic seizures), low muscle tone, coordination and walking difficulties, sleep disturbances, autism spectrum disorder, attention and behavioural difficulties, and gastrointestinal problems. Some individuals may also experience developmental regression, with the loss of previously acquired skills.

SLC6A1-NDD is increasingly recognised within the spectrum of genetic developmental and epileptic encephalopathies (DEEs). Epilepsy is a major feature of the condition, although clinical manifestations and their severity vary considerably, and not all affected individuals develop epilepsy.

ESTIMATED BIRTH

INCIDENCE

1 in 38,000

SLC6A1-related neurodevelopmental disorder is estimated to occur in approximately 1 in 38,000 live births. This corresponds to around 26 affected children for every million babies born.

Source: López-Rivera et al., 2020

GABA

REGULATION

GAT-1

SLC6A1 encodes GAT-1, which clears GABA—the brain’s main inhibitory neurotransmitter—from the space between nerve cells. This process helps control the duration of GABA signalling and maintain balanced activity in the brain.

AUTISM-

ASSOCIATED GENE

Top 10

SLC6A1 ranked among the top 10 genes showing the strongest enrichment of genetic variants in people with autism compared with controls in a large sequencing study.

Source: Satterstrom et al., 2020

EPILEPSY

~90%

SLC6A1-NDD is increasingly recognised as a genetic developmental and epileptic encephalopathy (DEE), with epilepsy affecting around 90% of clinically identified individuals.

Source: Goodspeed et al., 2020

Samanta D. (2026)

DEVELOPMENTAL DELAY

~97%

Developmental delay was reported in 61 of 63 individuals with SLC6A1-NDD in a 2026 study by Varnet et al., affecting areas such as speech, motor skills and cognitive development.

Source: Varnet et al. (2026)

Lisbon, August 2025

First European SLC6A1 Symposium

In August 2025, the first European SLC6A1 Symposium took place in Lisbon, bringing together families, researchers, clinicians and industry representatives committed to advancing knowledge and therapeutic development for SLC6A1-NDD.

Our research network

GABAnet

GABAnet brings together researchers across Europe working on SLC6A1 to strengthen collaboration, share expertise and develop joint research projects aimed at advancing our understanding of the disorder and accelerating therapeutic development.

Researchers and patient advocates at the first European SLC6A1 Symposium, Lisbon, August 2025.