Morquio syndrome

The Morquio syndrome (type IV mucopolysaccharidosis) is associated with the excretion of large amounts of keratan sulfate in the urine.389 The patients appear to have a normal pattern of enzymic activities in the liver lysosomes.399 Types V (Scheie syndrome) and... 

Chih-Kuang C, Shuan-Pei L, Shyue-Jye L, Tuen-Jen W (2002) MPS screening methods, the Berry Spot and acid turbidity tests, cause a high incidence of false-negative results in San-filippo and Morquio syndromes. J Clin Lab Anal 16 253-258... 

Northover H, Cowie RA, Wraith JE (1996) Mucopolysaccharidosis type IVA (Morquio syndrome) a clinical review. J Inherit Metab Dis 19 357-365... 

Compound 7 is a so-called diantennary oligosaccharide it can be isolated from the urine of patients suffering from GMj-gangliosi-dosis,52,63-643 as well as from64,65 Morquio syndrome type B. The 500-MHz, H-n.m.r. spectrum of 7 is presented in Fig. 7, and the chemical shifts of the structural-reporter groups are summarized in Table IV. 

Compound 11 has been isolated from the urine of patients suffering from GM,-gangliosidosis52 64,643 or from64 65 Morquio syndrome type B. This reducing decasaccharide is isomeric with oligosaccharide 10. It contains three N-acetyllactosamine units, the third unit being attached to 0-6 of Man-4. This structure is denoted as a tri -antennary oligosaccharide. 

F-1) The mucopolysaccharidoses are proteoglycan disorders that generally result from a hereditary lysosomal defect in enzymes that normally degrade mucopolysaccharides (in most cases heparan sulfate and dermatan sulfate). This leads to the accumulation of different mucopolysaccharides, which may be associated with a variety of different findings, commonly including mental retardation and various skeletal abnormalities. These diseases include Hunter disease, Hurler and Scheie disease, I-cell disease , Maroteaux-Laury disease, Morquio syndrome, Mucolipidoses VH disease, multiple sulfatase deficiency, and Sanfilippo A and B diseases, which will not be elaborated on further here. Often these conditions can be detected in advance on amniocentesis. 

Stepwise degradation of keratan sulfate. The deficiency diseases corresponding to the numbered reactions are 1 = MPS IV A, Morquio syndrome type A 2 = MPS IVB, Morquio syndrome type B 3 = MPS III D, Sanfilippo s syndrome type D 4 = Sandhoff s disease and 5 = Tay-Sachs and Sandhoff s disease. The alternate pathway releases intact N-acetylglucosamine-6-sulfate, a departure from the usual stepwise cleavage of sulfate and sugar residues. [Reproduced with permission from E.F. Neufeld and J. Muenzer In Metabolic Basis of Inherited Disease, 7th ed., C. R. Scriver, A. L. Beaudet, W. S. Sly, and D. Valle (Eds). McGraw-Hill, New York, 1995, p. 2468.]... 

Other causes Hunter syndrome, Hurler syndrome, or Morquio syndrome... 

Minami, R., Abo, K., Kudoh, T., Tsugawa, S., Oyanagi, K., and Nakao, T., Activities ofN-acetylgalactosamine 6-sulfate sulfatase in liver from two sisters with Morquio syndrome. Tohoku J. Exp. Med. 131, 53-57 (1980). 

There are two forms of Morquio syndrome. The Morquio syndrome, type A is characterized by significant physical and skeletal abnormalities after birth with no neurological problems in childhood. Corneal clouding, enlarged liver, development of abnormal teeth, and hearing loss occur later in the course of the disease. Urinary excretion of increased quantities of keratan sulfate and/ or chondroitin-6-sulfate is strongly suggestive of the Morquio syndrome. The prevalence of Morquio syndrome, type A is estimated at 1 in 169,000 [2]. 

The Morquio syndrome, type B is somewhat milder than that of the type A. Onset is about the same as in the type A. The milder clinical manifesta-... 

Table 18.7. N-Acetylgalactosamine 6-Sulfatase (Morquio syndrome, type A, MPS IVa) Table 18.8. y -D-Galactosidase (Morquio syndrome, type B, MPS IVB) ...

The Morquio syndrome, type B phenotype encompasses similar symptoms, is more variable and is rarer than type A. 

Also grouped with the mucopolysaccharidoses can be the true Morquio syndrome with extraskeletal manifestations and keratosulfaturia present. 

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