A small rural fishing village in the state of Zulia

Last updated: 1/17/2023

A small rural fishing village in the state of Zulia Venezuela has the highest concentration of people suffering from Huntington s Disease in the world In 1979 scientists caught wind of the alarming rates of HD in this area Several research teams were sent to meet with the people in the village and take blood samples to examine their DNA The data that was collected and continues to be collected from the people of this village has led to astounding advancements of our knowledge of the disease which will hopefully one day lead to better treatments prevention and maybe even a cure Scientists were able to obtain over 4 000 blood samples for DNA analysis as well as an immense amount of clinical data i e family history symptoms etc Using this data they were able to determine the source of the devastating genetic mutation a single woman who helped found the village ten generations prior Currently there are over 18 000 individuals living in this area of Venezuela who have Huntington s Disease Examine Figures 1 and 2 below then answer the corresponding questions bab inanimob Is to have chlide 00 II of Onset Charcot Marie Troth they might have more of an effect than you imagine your genes matter to anyone besides you Do they affect the rest of the population Well as it turns out mutation known as a triplet expansion The triplet expansion occurs on a mutated HTT gene where a triplet of Huntington s disease HD is a rare autosomal dominant neurodegenerative disease caused by a type of the disease individuals who have 6 35 CAG repeats will be unaffected while people with 40 or more CAG repeats are nucleotides CAG is repeated several times The number of repeats also plays an important role in the age of onset of guaranteed to develop symptoms of the disease HD is unique in that the symptoms and onset of the disease begin in adulthood and usually appear around the age of 30 45 this means that many people who have the disease have already had kids and passed on the genetic trait before their symptoms even appeared Symptoms of HD include a loss of motor control altered personality and a decline in overall cognitive function The disease is fatal and there are no current treatments to slow the progression of the disease IIIth IV Fig 1 Pedigree depicting four generations of a Venezuelan Huntington s Disease family Circles represent females and squares represent males A shaded symbol means they are affected with the disease A slashed symbol means the individual has died 80 60 I 40 Ione I 20 pitice of 11 44 48 Triplet Repeat Length CAG T T 52 56 38 T 60 of the triplet Fig 2 Box plot representing the age of onset vs the expansion The larger the boxes the more data that fell within that range