What is Difference Between Tay-Sachs Disease and Niemann-Pick Disease

The key difference between Tay-Sachs disease and Niemann-Pick disease is that Tay-Sachs disease is caused due to deficiency of β-hexosaminidase A, which leads to the build-up of GM2 ganglioside within the cells, while Niemann-Pick disease is caused due to a deficiency of sphingomyelinase, which leads to a build-up of sphingomyelin within the cells.

Tay-Sachs disease and Niemann-Pick disease are two autosomal recessive lysosomal storage disorders. They have common symptoms such as cherry red spots in the macula, central nervous system damage, regression in the development, seizures, hypotonia, and areflexia. Moreover, both these disorders are caused due to deficiency of a specific enzyme.

CONTENTS

1. Overview and Key Difference
2. What is Tay-Sachs Disease
3. What is Niemann-Pick Disease
4. Similarities – Tay-Sachs Disease and Niemann-Pick Disease
5. Tay-Sachs Disease vs Niemann-Pick Disease in Tabular Form
6. Summary – Tay-Sachs Disease vs Niemann-Pick Disease

What is Tay-Sachs Disease?

Tay-Sachs disease is caused by a deficiency of the enzyme β-hexosaminidase A. This deficiency leads to a build-up of GM2 ganglioside within the cells. The absence of this enzyme helps to break down fatty substances, which eventually leads to the build-up of fats to toxic levels in the brain and spinal cord. This affects the function of the nerve cells. The symptoms of this condition may include cherry red spots in the eyes, loss of motor skills, muscle weakness, movement problems, seizures, hearing loss and deafness, problems in swelling, behaviour problems, frequent respiratory infections, slow loss of speech, a decline in mental function and responsiveness, clumsiness, tremors and muscle spasms, loss of ability to walk, and psychiatric disorders. Tay-Sachs disease is caused due to mutation of a gene called the HEXA gene.

Moreover, Tay-Sachs disease is diagnosed through family history, physical examination, diagnostic blood test, genetic testing, and eye examination. Furthermore, treatment options for Tay-Sachs disease include medications (anti-seizure and antibiotic medicines), respiratory care, nutrition and hydration, physical therapy, occupational therapy, and speech and language therapy. The potential future treatments include gene therapy, stem cell transplantation, and enzyme replacement therapy.

What is Niemann-Pick Disease?

Niemann-Pick disease is caused due to a deficiency of the enzyme sphingomyelinase, which leads to a build-up of sphingomyelin within the nerve cells. It is a rare inherited disease that is due to the body’s inability to metabolize fats within cells. The accumulation of sphingomyelin within cells over time leads to the death of these cells. Niemann-Pick disease can affect the brain, nerves, liver, spleen, bone marrow, and lungs. The symptoms of this condition may include clumsiness and difficulty walking, dystonia or eye movements, sleep disturbances, difficulty swallowing or eating, and recurrent pneumonia. Moreover, this disease is caused by mutations in a specific gene (a mutation in a gene known as SMPD1) related to the metabolizing of fats such as cholesterol and lipids.

Niemann-Pick disease can be diagnosed through family history, blood and skin biopsy, MRI, eye examination, genetic testing, and prenatal testing. Furthermore, treatment options for Niemann–Pick disease may include the miglustat (Zavesca) drug, which improves neurological symptoms, and physical therapy.

What are the Similarities Between Tay-Sachs Disease and Niemann-Pick Disease?

• Tay-Sachs disease and Niemann-Pick disease are two different lysosomal storage disorders.
• Both are rare inherited autosomal recessive disorders.
• They have common symptoms such as cherry red spots in the macula, central nervous system damage, regression in the development, seizures, hypotonia, areflexia, etc.
• Both these disorders are caused due to deficiency of a specific enzyme.
• There is no exact cure for both disorders, and they are treated by improving the symptoms.

What is the Difference Between Tay-Sachs Disease and Niemann-Pick Disease?

Tay-Sachs disease is caused due to a deficiency of β-hexosaminidase A, which leads to the build-up of GM2 ganglioside within the cells, while Niemann-Pick disease is caused due to a deficiency of sphingomyelinase, which leads to a build-up of sphingomyelin within the cells. Thus, this is the key difference between Tay-Sachs disease and Niemann-Pick disease. Furthermore, Tay-Sachs disease is due to a mutation in a specific gene called the HEXA gene. On the other hand, Niemann-Pick disease is due to a mutation in a specific gene called SMPD1.

The below infographic presents the differences between Tay-Sachs disease and Niemann-Pick disease in tabular form for side-by-side comparison.

Summary – Tay-Sachs Disease vs Niemann-Pick Disease

Tay-Sachs disease and Niemann-Pick disease are two autosomal recessive lysosomal storage disorders. Both these disorders have some similar symptoms. Tay-Sachs disease is caused due to a deficiency in β-hexosaminidase A, leading to the build-up of GM2 ganglioside within the cells. Niemann-Pick disease is caused due to a deficiency in sphingomyelinase, leading to the build-up of sphingomyelin within the cells. So, this summarizes the difference between Tay-Sachs disease and Niemann-Pick disease.

Reference:

1. “Tay-Sachs disease.” NHS Choices, NHS.
2. “Niemann-Pick Disease: Medlineplus Genetics.” MedlinePlus, U.S. National Library of Medicine.

Image Courtesy:

1. “Tay-sachsUMich” By Jonathan Trobe, M.D. (CC BY 3.0) via Commons Wikimedia
2. “Niemann–Pick disease” By humpath.com – Niemann-Pick disease (CC BY 2.0) via Commons Wikimedia