Huntington's Disease Gene Hunters: An Expanding Tale.

Anne E Rosser,Lesley Jones

doi:10.1002/mdc3.13375

Abstract

Huntington's Disease Gene Hunters: An Expanding Tale.

Highlights

It is 28 years since the Huntington’s Disease (HD) gene and mutation were identified and published in Cell by the Huntington’s Disease Collaborative Research Group (HDCRG; Fig. 1A).[1]
In the HD-CRG paper, the authors commented on a possible link between CAG repeat number and age of onset, noting the very long repeats seen in juvenile cases
They noted instability of the repeat when transmitted to the generation as underlying the phenomenon of genetic anticipation in which subsequent generations can have progressively earlier disease onsets, and demonstrated the link to paternal transmission, with the longest expansions see in juvenile cases where transmission occurred through the paternal line

Summary

IN FOCUS HISTORICAL REVIEW

In the HD-CRG paper, the authors commented on a possible link between CAG repeat number and age of onset, noting the very long repeats seen in juvenile cases They noted instability of the repeat when transmitted to the generation as underlying the phenomenon of genetic anticipation in which subsequent generations can have progressively earlier disease onsets, and demonstrated the link to paternal transmission, with the longest expansions see in juvenile cases where transmission occurred through the paternal line. The publication of the gene sequence was rapidly followed by the availability of a genetic test which revolutionized preclinical testing by eliminating the need for complicated linkage analysis and provided near 100% accuracy (full penetrance for expansions of 40 and above, with incomplete penetrance for repeats of 36–39) This has made confirmation of diagnosis in symptomatic individuals easier and raised awareness of the HD phenocopy conditions, the genetic basis for many of these conditions having been established. The emergence of a reliable genetic test underpinned a number of important large longitudinal observational studies, starting with the North American’s Huntington’s Study group’s Cooperative Huntington Observational Research Trial (COHORT),[14] followed by the European HD network

IN FOCUS

Findings

Disclosures