ML I

ML I – Neuramidase Deficiency/Sialidosis

Mucolipidosis type I (ML I), also known as Sialidosis, is a rare inherited lysosomal storage disease that has clinical and histologic findings similar to the mucopolysaccharidoses and the sphingolipidoses. Symptoms of ML I are either present at birth or develop within the first year of life. In many infants with ML I, excessive swelling throughout the body is noted at birth. These infants are often born with coarse facial features, such as a flat nasal bridge, puffy eyelids, enlargement of the gums, and excessive tongue size (macroglossia). Many infants with ML I are also born with skeletal malformations such as hip dislocation. Infants often develop sudden involuntary muscle contractions (called myoclonus) and have red spots in their eyes (called cherry-red macules). They are often unable to coordinate voluntary movement (called ataxia). Tremors, impaired vision, and seizures also occur in children with ML I. Tests reveal abnormal enlargement of the liver and spleen and extreme abdominal swelling. Infants with ML I generally lack muscle tone (hypotonia) and have impaired intellect that is either initially or progressively severe. Many patients suffer from failure to thrive and from recurrent respiratory infections. 

For more information please email mps@mpssociety.org.uk.