Illinois siblings suffer from Sanfilippo syndrome, a dementia-like disease: Doctor explains the rare disorder
Illinois couple Megan Kempf and Kyle are parents to Poppy, 9, and Oliver, 2, who suffer from a dementia-like condition called Sanfilippo syndrome, which is also called childhood dementia.“Life is taken away from these children before they even have a chance to live it,” Megan told PEOPLE. The mom says her elder one is a different kid now than what she was few years before. “She used to love helping in the kitchen, dressing her dolls, helping her daddy in the yard, playing in the pool. None of those things happen anymore. And Oliver, we know, is already fighting against his own body, but is a seemingly normal, bright, hilarious little boy. No one would expect that anything is wrong with him, let alone that he’s already battling a terminal illness,” she told the media outlet. In November, the couple shared a video on Instagram showing the life of Oliver and Poppy. World Sanfilippo Day is observed on November 16.“Sanfilippo syndrome, also medically referred to as Mucopolysaccharidosis type III (MPS III), is a rare genetic disorder of metabolism. Although it has been referred to as “childhood dementia,” this term actually describes a progressive decline in cognitive and motor skills that resembles the deterioration seen in older patients with Alzheimer’s disease. However, due to its distinct biological cause, the two terms cannot be used interchangeably,” says Dr. Ritu Jha, Director & HOD – Neurology, Sarvodaya Hospital, Sector-8, Faridabad.“Essentially, Sanfilippo Syndrome is a lysosomal storage disease. A normal body has a way of disposing of its wastes through the “recycling stations,” or lysosomes. However, a child suffering from Sanfilippo Syndrome cannot degrade a type of long-chain sugar molecule named heparan sulfate. This molecule is not able to be eliminated from the body and gradually builds up inside the cells until it reaches a poisonous level. This causes permanent and progressive damage to the central nervous system and the brain,” Dr Ritu says and explains why it happens.
Why does it happen?
The condition is entirely genetic and follows an autosomal recessive inheritance pattern. This means a child must inherit one copy of the defective gene from each parent to develop the syndrome. The biological “glitch” occurs due to a deficiency in one of four specific enzymes required to degrade heparan sulfate. Depending on which enzyme is missing, the disease is categorized into four types:Type A: The most common and often most severe form.Type B, C, and D: Caused by different enzyme deficiencies but resulting in similar clinical outcomes.
The stages of progression and warning signs
As per the expert, the development of Sanfilippo syndrome begins with a gradual and abnormal progression of development in three stages, and ends with complete physical dependence. The first stage (1-4 years of age), where a child may show minimal delays in speech development or an increase in coarseness of their facial features, such as a broad forehead or heavy eyebrows, can often lead to incorrect diagnoses of the syndrome as other developmental delays or frequent ear infections.The doctor says the second stage is characterized by significant behavioral and cognitive decline. Between the ages of five and ten, the accumulation of cellular waste in the brain leads to extreme hyperactivity, sleep disturbances, and a loss of previously acquired skills, such as language or toilet training. This “dementia-like” phase is often the most taxing for families as the child’s behavior becomes increasingly difficult to manage. Finally, the third stage involves a slowing of the system. The hyperactivity fades, replaced by a loss of motor function. Children eventually lose the ability to walk, swallow, and move independently, requiring full-time palliative support as the body’s physical systems begin to fail.“Sanfilippo syndrome is often misdiagnosed due to early signs like speech delays and hyperactivity that can be seen in other common conditions, such as Autism or ADHD. It is often only when the physical “coarsening” of features or significant developmental regression occurs that metabolic testing is performed. Currently, no cure exists for Sanfilippo syndrome, and recent medical treatment involves palliation of sleep disturbances, seizures, and physical therapy so that patients may remain mobile as long as possible. Several clinical trials are underway to explore new treatments using both gene therapy and enzyme replacement. These treatments attempt to repopulate the brain with the missing enzymes that cause Sanfilippo,” Dr Ritu says.
