Targeted gene(s)/phenotype under study

ATXN1 (MIM: 601556); spinocerebellar ataxia type 1 (MIM: 164400)Name of the gene/phenotype


We identified two de novo truncating variants in ATXN1, in patients with neurodevelopmental disorders and without spinocerebellar ataxia. ATXN1 is known to cause spinocerebellar ataxia type 1 (SCA1) with a CAG triplet expansion mechanism (polyglutamin) leading to a gain-of-function mechanism.

To date, only one manuscript report 4 families (PMID: 28288114) with neurodevelopmental anomalies and also without SCA1. They suggest that a loss-of-function mechanism is the reason of this disorder, rather than a gain-of-function as described in SCA1.

Therefore, we are collecting ATXN1 truncating variants and CNV encompassing ATXN1, in patients with neurodevelopmental disorders / intellectual disability, and negative for another molecular cause.

We aim to increase our cohort and perform a genotype-phenotype correlation of these patients, to better delineate this syndrome.

Coordinating clinicians/researchers

Dr Frederic Tran-Mau-Them (MD, PhD)

Dr Quentin Thomas (MD)


UF6254 Innovation en Diagnostic Genomique des Maladies Rares
CHU Dijon

Specific requirements beyond clinical data and genotype data sharing

  • Re-analysis of DNA samples: No (if de novo occurrence proven)
  • Resampling of patients: No (if de novo occurrence proven)
  • Linked to a translational/basic research project: No