GM2 Gangliosidosis

GM2 gangliosidosis is a rare genetic disorder that progressively destroys nerve cells in the brain and spinal cord. The most common form of the disease typically presents in infancy, but various other forms can present in childhood, adolescence, or even adulthood.

GM2 gangliosidosis is sometimes called Tay-Sachs disease or HexA deficiency. The disorder is one of about 50 diseases that are classified as lysosomal storage disorders (LSD), where a genetic variation disrupts the normal activity of lysosomes in human cells.

What are lysosomes and what do they do?

Lysosomes contain specific proteins (enzymes) that are responsible for breaking down and recycling molecules such as fats and sugars. Individuals with a lysosomal storage disorder lack one of these necessary enzymes or do not have one of these enzymes in sufficient quantities to break down molecules for proper cell function. As a result, fats and sugars normally broken down by lysosomes can accumulate to toxic levels in the body’s cells and tissues, eventually leading to signs of disease.

What causes GM2 gangliosidosis in children?

GM2 gangliosidosis is most often caused by a mutation in the HEXA or the GM2A gene, which prevents an enzyme called beta-hexosaminidase A from properly breaking down large molecules inside the body’s cells. This genetic condition is inherited in an autosomal recessive pattern, which means that an affected child has received one defective copy of the gene from each of their parents.

What are the symptoms of GM2 gangliosidosis?

The severity of symptoms and the time at which they first present can vary in GM2 gangliosidosis. Children with this disease typically show no signs at the time of birth and develop normally during the first few months of life.

Signs and symptoms may include:

• slowing of growth
• plateau of gross and fine motor development
• developmental regression
• poor muscle tone (hypotonia)
• exaggerated startle reaction
• seizures
• visual impairment
• hearing loss
• intellectual disability

Treatment for GM2 gangliosidosis

There are currently no approved therapies to reverse the effects of GM2 gangliosidosis. Current approaches involve interdisciplinary collaboration to provide targeted management for specific symptoms.

How we care for GM2 gangliosidosis

At the Boston Children’s Lysosomal Storage Disorder (BoLD) Program, our team of providers is committed to the care of complex patients. As part of Boston Children’s Hospital, we are prepared to meet the challenge of providing multifaceted care by partnering with you and your child to deliver direct care in our BoLD clinic. We work with the broad array of world-class specialists at Boston Children’s to optimize the care we provide your child with GM2 gangliosidosis.