Abstract
Purpose To describe a clinical case of mucopolysaccharidosis type VI (MPS VI), or Maroteaux-Lamy syndrome, with fundoscopic alterations that may correspond to scleral deposits of glycosaminoglycans. Materials and Methods Clinical case report. Results A 16-year-old girl with MPS VI was examined at the Ophthalmology Department for poor vision due to opacified corneas. Treatment consisted of bilateral penetrating keratoplasty. Retinographies and enhanced depth imaging optical coherence tomography (EDI-OCT) were performed after surgery, suggesting the presence of scleral glycosaminoglycan deposits. The patient evolved with stable corneal and fundoscopic findings. Conclusions To our knowledge, this is the first case of MPS VI described in vivo with suspected deposits of glycosaminoglycans in the sclera. Fundoscopic alterations are not usually included in the ocular pathological spectrum of MPS VI. However, with improved control of systemic comorbidities, survival rates of these patients have increased, which in turn has made it possible to observe other changes besides the ones that were classically described. Despite being particularly challenging to manage, efforts should be made to maximizing the visual acuity of these patients, in order to provide them the best possible quality of life.
Highlights
Mucopolysaccharidoses (MPSs) are a group of disorders caused by inherited defects in lysosomal enzymes resulting in widespread intra and extracellular accumulation of glycosaminoglycans [1].MPS type VI (MPS VI), or Maroteaux-Lamy syndrome, is a very rare disorder with an incidence ranging from 0.36 to 1.30 per 100,000 [2]
It is an autosomal recessive disorder caused by a deficient activity of the enzyme N-acetylgalactosamine 4-sulfatase, which is involved in the degradation of the glycosaminoglycans dermatan sulfate and chondroitin 4-sulfate. Deficient levels of this enzyme lead to the accumulation of partially degraded glycosaminoglycans in tissues and organs, which in turn causes a wide range of clinical manifestations, including abnormal structural development, lung infections, sleep apnoea, cardiac valvular disease, and a characteristic facies, with enlarged tongue, flat nasal bridge, and macrocephaly, that progressively worsens with age
Ocular accumulation of glycosaminoglycans results in progressive corneal opacification and is the main reason for the low visual acuity of these patients as well as the difficulty in observing the retina and optic nerve in detail
Summary
Mucopolysaccharidoses (MPSs) are a group of disorders caused by inherited defects in lysosomal enzymes resulting in widespread intra and extracellular accumulation of glycosaminoglycans [1]. MPS type VI (MPS VI), or Maroteaux-Lamy syndrome, is a very rare disorder with an incidence ranging from 0.36 to 1.30 per 100,000 [2] It is an autosomal recessive disorder caused by a deficient activity of the enzyme N-acetylgalactosamine 4-sulfatase, which is involved in the degradation of the glycosaminoglycans dermatan sulfate and chondroitin 4-sulfate. Deficient levels of this enzyme lead to the accumulation of partially degraded glycosaminoglycans in tissues and organs, which in turn causes a wide range of clinical manifestations, including abnormal structural development, lung infections, sleep apnoea, cardiac valvular disease, and a characteristic facies, with enlarged tongue, flat nasal bridge, and macrocephaly, that progressively worsens with age. Retinal changes are not usually associated with MPS VI [3,4,5]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
