Mucopolysaccharidoses

Philip Mathew

Mucopolysaccharide (or proteoglycan): a linear carbohydrate polymer with more than one kind of monosaccharide, linked covalently to a protein core.

Glycosaminoglycan (GAG): the carbohydrate portion of the mucopolysaccharide.

Mucopolysaccharidoses: a group of diseases that result in the inability of lysosomes to degrade mucopolysaccharides.

Diseases arise due to a deficiency of a number of lysosomal hydrolases.

Deficiency: a-L-iduronidase

Urinary Metabolites: heparan sulfate, dermatan sulfate

Inheritance: AR

Symptoms: musculoskeletal abnormalities, corneal clouding, neurological deterioration, cardiovascular abnormalities

Type I: Hurler’s

Deficiency: Iduronosulfate sulfatase

Urinary Metabolites: heparan sulfate, dermatan sulfate

Inheritance: XR

Symptoms: musculoskeletal abnormalities, neurological deterioration

Type II: Hunter’s

4 variants

Type A: Heparan-N-sulfataseType B: a-N-acetylglucosaminidaseType C: Acetyl-Coa-glucosaminide

acetyltransferaseType D: N-acetylglucosamine-6-sulfatase

Type III: Sanfillipo’s

Urinary Metabolites: heparan sulfate

Inheritance: AR

Symptoms: musculoskeletal abnormalities, neurological deterioration

Deficiency: N-acetylgalactosamine-6-sulfatase

Urinary Metabolites: keratan sulfate, chondroitin-6-sulfate

Inheritance: AR

Symptoms: musculoskeletal abnormalities, corneal clouding, cardiovascular abnormalities

Type IV: Morquio’s

Deficiency: a-L-iduronidase

Urinary Metabolites: heparan sulfate, dermatan sulfate

Inheritance: AR

Symptoms: musculoskeletal abnormalities, corneal clouding, cardiovascular abnormalities

Type V: Scheie’s

Deficiency: N-acetylgalactosamine-4-sulfatase

Urinary Metabolites: dermatan sulfate

Inheritance: AR

Symptoms: musculoskeletal abnormalities, corneal clouding, cardiovascular abnormalities

Type VI: Maroteaux-Lamy’s

Deficiency: b-glucuronidase

Urinary Metabolites: heparan sulfate, dermatan sulfate

Inheritance: AR

Symptoms: musculoskeletal abnormalities, corneal clouding, cardiovascular abnormalities

Type VII: Sly’s