Tay Sachs

By: Azeen Bemani

About Tay Sachs

Tay-Sachs disease happens when the body lacks hexosaminidase A, a protein that helps break down a chemical found in nerve tissue called gangliosides. Without this protein, gangliosides, particularly ganglioside GM2, build up in cells, especially nerve cells in the brain.

Tay-Sachs disease is caused by a defective gene on chromosome 15. When both parents carry the defective Tay-Sachs gene, a child has a 25% chance of developing the disease. The child must receive two copies of the defective gene -- one from each parent -- in order to become sick. If only one parent passes the defective gene to the child, the child is called a carrier. He or she won't be sick, but will have the potential to pass the disease to his or her own children.

Anyone can be a carrier of Tay-Sachs, but the disease is most common among the Ashkenazi Jewish population. About 1 in every 27 members of the Ashkenazi Jewish population carries the Tay-Sachs gene.

Tay-Sachs has been classified into infantile, juvenile, and adult forms, depending on the symptoms and when they first appear. Most people with Tay-Sachs have the infantile form, when the nerve damage usually begins while the baby is still in the womb. Symptoms usually appear when the child is 3 to 6 months old. The disease tends to get worse very quickly, and the child usually dies by age 4 or 5.

History

Warren Tay- The disease is named for Warren Tay (1843-1927), a British ophthalmologist who in 1881 described a patient with a cherry-red spot on the retina of the eye.

Bernard Sachs- It is also named for Bernard Sachs (1858-1944), a New York neurologist whose work several years later provided the first description of the cellular changes in Tay-Sachs disease. Dr. Sachs also recognized the familial nature of the disorder, and, by observing numerous cases, he noted that most babies with Tay-Sachs disease at that time were of Eastern European Jewish origin. Today, Tay-Sachs occurs among people of all backgrounds.

Symptoms

Deafness

Decreased eye contact, blindness

Decreased muscle tone (loss of muscle strength)


Delayed mental and social skills

Dementia

Increased startle reaction

Irritability

Loss of motor skills

Paralysis or loss of muscle function

Seizures

Slow growth

Treatments and Complications

Treatment- There is no treatment for Tay-Sachs disease itself, only ways to make the patient more comfortable.

Complications- Symptoms appear during the first 3 to 10 months of life and progress to spasticity, seizures, and loss of all voluntary movements.