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Morquio syndrome (referred to as mucopolysaccharidosis IV or Morquio) is a mucopolysaccharide storage disease (see also Lysosomal Storage Disorder), usually inherited. It is a relatively rare dwarfism with serious consequences on account of medical conditions and such. When the body cannot process certain types of mucopolysaccharides, they build up or are eliminated, causing various symptoms. Two forms are recognized, type A and type B. Type A is a deficiency of the enzyme N-acetylgalactosamine-6-sulfate sulfatase. Type B is the deficiency of the enzyme beta-galactosidase. The disease is caused by an abnormal accumulation of mucopolysaccharides - in this case, keratan sulfate - in the body. Keratan sulfate is excreted in urine. The symptoms vary from patient to patient, and may include hearing loss, cataracts, skeletal dysplasia, spinal instability, and minor respiratory issues, among others. The condition was first described, simultaneously and independently, in 1929, by Luis Morquio in Montevideo, Uruguay, and by James Frederick Brailsford in Birmingham, England. They both recognized the occurrence of corneal clouding, aortic valve disease, and urinary excretion of keratan sulfate. Morquio observed the disorder in 4 siblings in a family of Swedish extraction and, to further compound the international melange, reported his observations in French.

Note that much of the information available online regarding this disorder may be out of date and or incorrect.

The following symptoms are associated with morquio syndrome:

• Abnormal heart development
• Abnormal skeletal development
• Hypermobile joints
• Large fingers
• Knock-knees
• Widely spaced teeth
• Coarse facial features
• Large head
• Star shaped chest (ribs flared)
• Compression of spinal cord

As most mucopolysaccharidoses, Morquio syndrome exhibits alterations in white blood cells that are diagnostic, and might allow for screening procedures and cost-effective differential diagnosis in the future. These anomalies can be best studied with [Wright stain], the routine dye employed in hematology laboratory.Neutrophils in Morquio´s syndrome exhibit persistence of the azurophilia in its granules, which is explained by the deficient enzyme´s inability to clear them from mucopolysaccharides used as a tags in the cells vesicular sorting system. Approximately 70 percent of the neutrophils exhibit this subtle alteration. Differential diagnosis must be made with mucopolisaccharidoses I,II,III,VI and VII. Nonetheless, after this screening procedure has been carried on, quantitative enzyme determination assays must be conducted to verify the diagnosis, should any replacement treatment is available.

Complications that may develop include:^{[citation needed]}

• Heart failure
• Difficulty with vision
• Walking problems related to abnormal curvature of the spine
• Abnormal neck bones can cause spinal cord damage that can cause severe disease including paralysis if not caught early -- spinal fusion can prevent this
• Breathing problems
  • MedlinePlus Medical Encyclopedia entry
  • National MPS Society

  Morquio Foundation www.morquio.com

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  v • d • e Metabolic pathology (E70-90)
  Amino acid	Phenylketonuria - Alkaptonuria - Ochronosis - Tyrosinemia - Maple syrup urine disease - Propionic acidemia - Methylmalonic acidemia - Isovaleric acidemia - Primary carnitine deficiency - Cystinuria - Cystinosis - Hartnup disease - Homocystinuria - Citrullinemia - Hyperammonemia - Glutaric acidemia type 1
  Carbohydrate	Lactose intolerance - Glycogen storage disease (type I, type II, type III, type IV, type V, type VI), Fructose intolerance, Galactosemia
  Lipid	Lipid storage disorders Sphingolipidoses: Gangliosidosis - GM2 gangliosidoses (Sandhoff disease, Tay-Sachs disease) - GM1 gangliosidoses - Mucolipidosis type IV - Gaucher's disease - Niemann-Pick disease - Farber disease - Fabry's disease - Metachromatic leukodystrophy - Krabbe disease Neuronal ceroid lipofuscinosis (Batten disease) - Cerebrotendineous xanthomatosis - Cholesteryl ester storage disease (Wolman disease) Hyperlipidemia - Hypercholesterolemia - Familial hypercholesterolemia - Xanthoma - Combined hyperlipidemia - Lecithin cholesterol acyltransferase deficiency - Tangier disease - Abetalipoproteinemia
  Mineral	Cu Wilson's disease/Menkes disease - Fe Haemochromatosis - Zn Acrodermatitis enteropathica - PO43− Hypophosphatemia/Hypophosphatasia - Mg2+ Hypermagnesemia/Hypomagnesemia - Ca2+ Hypercalcaemia/Hypocalcaemia/Disorders of calcium metabolism
  Fluid, electrolyte and acid-base balance	Electrolyte disturbance - Na+ Hypernatremia/Hyponatremia - Acidosis (Metabolic, Respiratory, Lactic) - Alkalosis (Metabolic, Respiratory) - Mixed disorder of acid-base balance - H2O Dehydration/Hypervolemia - K+ Hypokalemia/Hyperkalemia - Cl− Hyperchloremia/Hypochloremia
  Porphyrin and bilirubin	Acatalasia - Gilbert's syndrome - Crigler-Najjar syndrome - Dubin-Johnson syndrome - Rotor syndrome - Porphyria (Acute intermittent porphyria, Gunther's disease, Porphyria cutanea tarda, Erythropoietic protoporphyria, Hepatoerythropoietic porphyria, Hereditary coproporphyria, Variegate porphyria)
  Glycosaminoglycan	Mucopolysaccharidosis - Hurler syndrome - Hunter syndrome - Sanfilippo syndrome - Morquio syndrome
  Glycoprotein	I-cell disease - Pseudo-Hurler polydystrophy - Aspartylglucosaminuria - Fucosidosis - Alpha-mannosidosis - Sialidosis
  Other	Alpha 1-antitrypsin deficiency - Cystic fibrosis - Familial Mediterranean fever - Lesch-Nyhan syndrome

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