New findings indicate that Juvenile Huntington’s should be separated into two distinct categories, which in turn may be treated differently. Children with a long mutation length shows a faster rate of disease progression compared to adults and children with a shorter length.
Squitieri and his international team found a relationship between mutation length and progression of Huntington’s disease. In other words: a high number of CAG-repeats causes a rapid development of the disease, leading to a shorter life-span and a developmental delay in the brain.
– Our study identifies the most aggressive juvenile-pediatric variant that affects children, Dr. Ferdinando Squitieri states.
Two variants of Juvenile Huntington’s disease
Children with Juvenile onset of Huntington’s disease (JHD) with a CAG-repeat over 80, shows a faster rate of disease progression and abnormalities in the brain – which is not reported in adults with Huntington’s disease and other juveniles with fewer CAG repeats.
Among many things, juveniles with a high number of CAG repeats, shows a underdeveloped Striatum (area of the brain) and a developmental delay in both psychic and motoric components.
These findings indicate that JHD may be separated into two distinct categories: those with a high number of CAG-repeats, and those with a shorter CAG-expansion. Further, this might imply that the two variants should be ‘attacked’ and treated in different ways.
– JHD is a very rare disease and it is therefore important to expand the focus. IHA will contribute to this with a JHD development program, the newly elected President of the International Huntington Association, Svein Olaf Olsen, states
What is CAG-repeats?
This description is a shortened version first published at HDBuzz.net
DNA is the code for all life and is made up of a combination of 4 ‘letters’ – A, C, G and T. The genetic mutation that causes HD is a long sequence of repeated C-A-G in the Huntington gene.
The number of CAG repeats in the Huntington gene determines whether or not someone will develop Huntington’s disease. The average number of CAG repeats is around 17. That’s why the number of CAG-repeats gets measured in a HD testing.
The facts are quite straightforward:
If both copies of a person’s HD gene contain 26 or fewer repeats, they will not develop Huntington’s disease, and nor will any of their children.
Or: if one copy of an person’s HD gene has 40 or more repeats, they will develop Huntington’s during their lifetime.
Few vs. many repeats
A person with Huntington’s disease may therefore have a CAG-repeat of 40 and another may have a repeat of 120.
Now Squitieri and his team is the first in the world to demonstrate a significant distinction between the two juvenile groups: those with 40 or less CAG-repeats, and those with 80 or more repeats.
This important finding may open the door to new therapeutic strategies for ‘attacking’ this rare variant of Huntington’s Disease.