Dentatorubral–pallidoluysian atrophy (DRPLA) is an autosomal dominant spinocerebellar degeneration caused by an expansion of a CAG repeat encoding a polyglutamine tract in the atrophin-1 protein.

Although this condition was perhaps first described by Smith et al. in 1958, and several sporadic cases have been reported from Western countries, this disorder seems to be very rare except in Japan.

Other symptoms that have been described include cervical dystonia,[3] corneal endothelial degeneration[4] autism, and surgery-resistant obstructive sleep apnea.

[8] Atrophin-1 may be a dispensable or redundant protein as mice bred with a null allele for atrophin-1 produce viable and fertile offspring and show no compensatory upregulation of atrophin-2.

[10][11][12] The Schilling mice express full-length human atrophin-1 with 65 CAG repeats under transcriptional control of the mouse prion protein promoter.

The hemizygous transgenic offspring of the Q129 mice exhibited symptoms similar to juvenile-type DRPLA, such as myoclonus and seizures.

Diffuse accumulation in the nuclei began on post-natal day 4 and ubiquitinated NII formation was detectable at 9 weeks of age.

No PML bodies were found to be associated with the NIIs, which were morphologically mildly altered from those seen in human neural cells.

The globus pallidus (lateral greater than medial segment) and subthalamic nucleus demonstrate consistent neuronal loss and astrocytic gliosis.

[citation needed] Morphometric analysis of DRPLA mouse brains has shown a loss of normal inter-microtubule spacing in neuronal axons.

The microtubules were relatively compacted, suggesting abnormalities in protein transport may play a role in neuronal degeneration.

[21] NIIs have also been demonstrated to alter the distribution of the intranuclear structures, such as promyelocytic leukemia protein (PML) nuclear bodies.

The extent and frequency of neurons showing the diffuse nuclear accumulations changes depending on CAG repeat length.

Family history can be difficult to obtain if a relative was misdiagnosed, died young, or experiences late onset of symptoms.

[citation needed] Other diseases in the differential diagnosis of adult-onset DRPLA include Huntington's and the spinocerebellar ataxias.