The diagnosis of mucopolysaccharidosis (MPS) VI is usually not made before the age of 2 or 3 years when the main clinical signs of dwarfed stature, skeletal deformities, coarsening facies, stiff joints and hepatosplenomegaly described in textbooks are recognisable. Conversely, accelerated growth with advanced bone age, a precocious feature of this condition although not suggestive of a storage disorder, is usually neither recognised, nor adequately interpreted. We report on two infants with MPS VI who presented with these two "unexpected" features within the 1st year of life.
Conclusion: Recognition of precocious excessive growth in a mucopolysaccharidosis enables an early diagnosis, the prime responsibility of the clinician, in order to propose early treatment like bone marrow transplantation or active recombinant sulphatase therapy, and appropriate genetic counselling.