Mucopolysaccharidosis (MPS) is a group of rare inherited metabolic disorders caused by deficiencies in specific enzymes required to break down substances called glycosaminoglycans (GAGs). When these substances are not broken down properly, they accumulate in cells and tissues, gradually affecting different organs and body systems.
There is no single first sign of mucopolysaccharidosis (MPS). The earliest symptoms vary depending on the type of MPS, the severity of the enzyme deficiency, and the age at which the disease begins to affect the body.

Common early signs of mucopolysaccharidosis
Some children with MPS develop symptoms during infancy, although they may appear healthy at birth.
– Hernias: Umbilical or inguinal hernias may be among the earliest noticeable signs.
– Frequent ear infections: Recurrent ear infections and hearing difficulties can occur.
– Persistent nasal congestion: A constantly blocked nose, recurrent respiratory infections, or noisy breathing may develop.
– Developmental delays: Some children may take longer to achieve milestones such as walking, speaking, or learning new skills.
– Joint stiffness: Restricted movement, particularly in the fingers and other joints, may become noticeable.
– Enlarged liver or spleen: Accumulation of GAGs can cause enlargement of internal organs.
– Changes in facial features: Some children gradually develop characteristic facial features, including a broad nose, fuller lips, or a prominent forehead.
– Skeletal abnormalities: Short stature, changes in bone development, and spinal abnormalities may develop over time.

Not every child experiences all these symptoms. Some features may also occur in other medical conditions, so their presence alone does not establish a diagnosis.

Are the first signs different in different types of MPS?
Yes. Different types of mucopolysaccharidosis can present differently.
For example, children with MPS I may develop hernias, recurrent respiratory infections, joint stiffness, and skeletal abnormalities. In MPS II, which is also known as Hunter syndrome, symptoms can include enlarged organs, joint problems, and developmental difficulties in some affected individuals.
In MPS III, also called Sanfilippo syndrome, early signs may be more subtle. Speech delay, behavioural changes, hyperactivity, difficulty sleeping, and developmental regression can be early clues. Physical features may be less obvious than in some other MPS types.
In MPS IV, or Morquio syndrome, skeletal abnormalities, short stature, and joint problems may be prominent, while intelligence is generally preserved.

When should parents seek medical advice?
Parents should consult a paediatrician if their child has unexplained developmental delays, multiple hernias, recurrent respiratory or ear infections, unusual skeletal features, or a combination of these symptoms.
When mucopolysaccharidosis is suspected, the doctor may recommend urinary GAG analysis, specific enzyme activity testing, and molecular genetic testing.