Maroteaux–Lamy syndrome

Maroteaux–Lamy syndrome
Other namesMucopolysaccharidosis type VI, MPS VI, or Polydystrophic dwarfism
A 16-year old boy with rapidly progressing MPS-VI, showing characteristic facial features and spinal deformities
SpecialtyEndocrinology 
SymptomsVariable. May include: Macrocephaly, Hydrocephalus, Coarse facial features, Heart valve disease, Enlarged liver and spleen, Umbilical hernia
Usual onsetPatients are affected at birth; symptoms usually appear during early childhood
DurationLifelong
CausesMutations in the ARSB gene
Differential diagnosisOther mucopolysaccharidosis disorders
PrognosisReduced life expectancy

Maroteaux–Lamy syndrome, or mucopolysaccharidosis Type VI (MPS-VI), is an inherited disease caused by a deficiency in the enzyme arylsulfatase B (ARSB). ASRB is responsible for the breakdown of large sugar molecules called glycosaminoglycans (GAGs, also known as mucopolysaccharides). In particular, ARSB breaks down dermatan sulfate and chondroitin sulfate. Because people with MPS-VI lack the ability to break down these GAGs, these chemicals build up in the lysosomes of cells. MPS-VI is therefore a type of lysosomal storage disease.