Here are the top interesting facts about Tay-Sachs disease:
#1 Tay-Sachs disease, also known as GM2 gangliosidosis Type 1, is a rare inherited neurodegenerative disorder that progressively destroys nerve cells in the spinal cord and brain.
#2 The majority of affected infants have symptoms appearing from age 3 to 6 months. Progression is rapid, and the sufferer will typically pass away by five years old.
#3 This inherited disease is categorized as a lysosomal storage disease (a group of approximately 50 rare inherited metabolic diseases). Lysosomes are the primary digestive units in cells.
Enzymes within this type of digestive units break down nutrients, such as fats and complex carbohydrates.
#4 This neurodegenerative disorder was first characterized by two doctors working independently, resulting in its hyphenated name: an American physician named Bernard Sachs and a British physician named Warren Tay.
#5 This condition is divided into the infantile or classic form, the juvenile form, and the late-onset or adult form.
#6 For patients with the late-onset form (LOTS), symptoms and signs may become apparent anytime until the mid-30s.
In individuals with infantile form, symptoms, and signs usually first occur between 3 and 6 months of age.
#7 The initial symptoms in the infantile form may include:
- delayed learning development;
- increased startle response;
- poor vision;
- a red dot visible near the center of the retina.
#8 Additional symptoms and signs can commonly be observed after about 8 months of age and develop very fast. They include:
- a lack of interest in the world around them;
- muscle stiffness;
- difficulties swallowing;
- a loss of hearing;
- increasing loss of vision;
- increasing muscle weakness which progresses to paralysis.
#9 Kids who have this neurodegenerative condition are at increased risk of lung conditions which may lead to accumulation of mucus in their lungs as well as breathing problems.
More importantly, young patients with this disorder can become blind, deaf, and paralyzed.
#10 Early signs and symptoms of LOTS include – fasciculations, muscle cramps, lack of coordination, muscle weakness in the legs, and dysarthria.
Approximately 40 percent of affected individuals have mental health symptoms, including – psychotic or bipolar (previously known as manic depression) episodes.
#11 This condition is caused by the absence of an essential enzyme, with the scientific term – hexosaminidase-A (Hex-A).
Without this crucial protein, gangliosides (found in the brain and other organs), especially ganglioside GM2, build up in cells, frequently nerve cells in the brain. This continuous accumulation ultimately leads to progressive damage to the cells.
#12 The Hex-A gene is one of approximately 30,000 to 70,000 genes in the human genome.
#13 All humans have two copies of the Hex-A gene. However, if an individual has one healthy copy of the hexosaminidase-A gene and the other copy has a problem with it, that individual is called a “carrier.”
#14 Anyone can be a carrier of the Tay-Sachs gene, however, this neurodegenerative condition is most frequent among the Ashkenazi Jewish population (most individuals with this unique ancestry trace their DNA to Central and Eastern Europe, and Middle Eastern).
According to statistics, 98% of Tay-Sachs cases result from one of 3 mutations in the Ashkenazi Jewish population. Also, one in every 27 members of this population carries the Hex-A gene.
#15 Other groups most at risk are French Canadians living near the Louisiana Cajuns and St. Lawrence River.
#16 An infant can only have this neurodegenerative disorder if both parents are carriers of the Hex-A gene. When two carriers have a baby, there is a:
- 25 percent chance that their baby will have the condition;
- 25 percent chance that their baby will not have the condition and not be a carrier;
- fifty percent chance that their baby will not have the disease, but be a carrier.
#17 This condition can be diagnosed before birth, through chorionic villus sampling and amniocentesis. Chorionic villus sampling can be executed between 10 and 14 weeks of the pregnancy and uses a cell sample from the placenta, taken via the abdomen or the vagina.
In amniocentesis, a needle is inserted into the uterus through the abdomen and a sample of amniotic fluid (the protective liquid contained by the amniotic sac) is removed for testing.
#18 There is no treatment for this neurodegenerative disorder, only methods to make the sufferer more comfortable. This may involve:
- psychosocial support for the family;
- physical therapy to maintain as much ability to move and help keep joints flexible;
- language and speech services;
- antiepileptic drugs for seizures;
- support for feeding and airway protection.
#19 If you are a member of a high-risk group or if you have a family history of this disorder and plan to have children, it is recommended that you should do genetic counseling and genetic testing.
#20 Most children pass away by the age of 4 or 5. However, if a child has the juvenile type of this neurodegenerative disorder, she or he commonly develop symptoms between the ages of 2 and 10.
They usually die between the ages of 5 and 15. If an adult has LOTS, she or he can develop symptoms from adolescence to their 30s or 40s.
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References https://www.genome.gov/10001220/learning-about-taysachs-disease/ https://ghr.nlm.nih.gov/condition/tay-sachs-disease https://clinicaltrials.gov/ct2/show/NCT01869270