Four RAN biomarkers not previously known to accumulate in Huntington’s disease have been discovered in a higher abundance in the brains of those affected by the disease and in early onset juvenile cases. More than 15,000 Americans have Huntington’s disease and about 150,000 others are at risk of developing the disease. Affected individuals have symptoms that include irritability, depression, involuntary jerking movements, poor coordination, trouble learning new information or making decisions, and trouble walking, speaking, and swallowing. Substantial evidence suggests that mutant huntingtin genes (HTT genes) and other expansion proteins contribute to the disease, but most treatment strategies focus on molecular readouts and attempt to reduce the only known expansion protein biomarker – polyGlutamine. Researchers at the University of Florida have discovered four proteins that accumulate in HD patients’ brains and amass in a significantly higher abundance in both affected brain regions and in juvenile onset cases. These RAN proteins are expressed by repeat-associated non-ATG translation (RAN translation) and will enable researchers to test the effectiveness of treatments and create tools to block RAN translation in HD.
Four RAN protein biomarkers enable testing for HD treatment effectiveness, allow for possible future prognosis markers, and help improve disease outcomes
Researchers have shown that polyAla, polySer, polyLeu and polyCys proteins are expressed in both the sense (positive) direction and the antisense (negative) direction in both affected brain regions and in juvenile onset cases. They are direct protein products of the mutation which are expressed in alternative reading frames without an ATG initiation codon.
