Early diagnosis of mucopolysaccharidosis type III (Sanfilippo syndrome) in the practice of a pediatrician

Abstract

Mucopolysaccharidosis (MPS) type III (Sanfilippo syndrome) is a lysosomal storage disease inherited in an autosomal recessive manner, it is characterized by the accumulation of heparan sulfate in the cells of the body, which leads to the development of multiple organ failure. It occurs with a frequency of 1: 70 thousand newborns. There are 4 subtypes of the disease: A, B, C, D. Cognitive and neurological disorders are the earliest symptoms of the disease. Delay (loss) of speech development, regression of acquired skills, hyperreactivity, autistic character traits, mental retardation, sleep disturbance, epilepsy are noted; aggressive behavior is formed, the ability to move is impaired, hepatomegaly appears. There are observed the violations of other organs and systems – the organ of vision, bone, respiratory, cardiovascular systems, ENT organs, dental problems. Clinically, the subtypes of mucopolysaccharidosis III are practically indistinguishable. The average age at diagnosis is 2–6 years. Diagnostic search includes qualitative and quantitative determination of glycosaminoglycans in urine. It should be remembered that with mild variants of the disease, these indicators may be within the normal range. In the future, it is necessary to assess the activity of the corresponding enzymes in leukocytes, plasma or serum, in skin fibroblasts. Genetic testing is then performed to identify the mutation of the corresponding defective gene. Differential diagnosis should be carried out with other types of mucopolysaccharidosis, mucolipidosis, gangliosidosis, multiple sulfatase deficiency, some rheumatoid diseases.