DAB1 (Spinocerebellar Ataxia 37) Repeat Expansion Testing
Description
Pathogenic ATTTC repeat expansions within the DAB1 gene have been associated with spinocerebellar ataxia type 37 (SCA37), characterized by adult onset progressive ataxia, dysarthria, dysphagia and abnormal ocular movements in the presence of cerebellar atrophy on MRI 1,2.
Pathogenicity is dependent upon ATTTC repeat length according to the following ranges 1-4:
Normal Alleles | Mutable Normal Alleles | Intermediate/Uncertain Alleles | Reduced Penetrance Alleles | Full Penetrance Alleles |
No ATTTC repeats within the ATTTT repeat region | - | 2-30 consecutive ATTTC repeats within the ATTTT repeat region | - | 31 or more ATTTC repeats within the ATTTT repeat region |