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GENATLAS PHENOTYPE
last update : 21-08-2009
Symbol MPS4A
Location 16q24.3
Name mucopolysaccharidosis, type IVA
Other name(s)
  • Morquio syndrome A
  • galactosamine-6-sulfatase deficiency
  • GALNS deficiency
    • Corresponding gene GALNS
    Main clinical features
  • various types of spondyloepiphyseal dysplasia and multiple epiphyseal dysplasia, prone to the dangerous complications of atlantoaxial dislocation, due to hypoplasia of the odontoid with high excretion of keratan sulfate
  • intelligence normal and no direct central nervous system involvement, although the skeletal changes may result in neurologic complications, early death
  • intracellular accumulation of keratan sulfate and chondroitin-6-sulfate
  • urinary glycosaminoglycans by a 2-dimensional electrophoresis technique was a reliable and efficient diagnostic assay with no false-negative results
    • Genetic determination autosomal recessive
    Function/system disorder metabolism/lysosomal
    Type disease
    Gene product
    Name galactose-6-sulfatase (GALNS)
    Mechanism(s)
    Gene mutationChromosome rearrangementEffectComments
    missense     R386C, I113F are most frequent, and G replaced by another residue (G301C)
    deletion     severe form
    frameshift     severe form
    Remark(s)