Hurler’s syndrome

Features of Mucopolysaccharidosis Syndrome-HURLER’S SYNDROME(MPS I H, Gargoylism):

  • Type- I-H
  • Eponym-Hurler
  • Inheritance-Autosomal Ressesive
  • Enzyme Deficiency- α-L-Iduronidase
  • Stored Substrate- HS- heparan sulfate and DS-dermatan sulfate
  • Clinical Features – Appears in infancy; cloudy corneas, growth retardation, reduced intelligence, coronary artery disease; rarely live 10 years.
  • Chromosomal abnormality on chromosome arm 4p16.3

  • Characterized by increased levels of MPS in urine.

Clinical features:-

  • Becomes apparent in first 2 years of life, life expectancy of 6-10 yrs.
  • Head appears large; facial features quite typical.
  • Prominent forehead
  • Broad saddle nose & wide nostrils
  • Puffy eyelids with coarse bushy eyebrows
  • Hypertelorism
  • Thick lips
  • Large tongue with open mouth
  • Nasal congestion & noisy breathing.
  • Progressive corneal clouding classic manifestation.
  • Hepatosplenomegaly, results in protrudent abdomen
  • Short neck & spinal abnormalities typical.
  • Flexion contractures result in “claw hand”.
  • Dwarfed, mentally retarded individuals.
  • hhs

Histologic features:-

  • Excessive accumulation of intracellular mucopolysaccarides in many tissues & organs.
  • Accumulation of dermatan & heparan sulfate in cells of mononuclear – phogocyte system, fibroblasts & endothelial cells.
  • Affected cells are swollen, have clear cytoplasm resulting from accumulation of PAS +ve material in engorged, vacuolated lysosomes.
  • Involved fibroblasts assume appearance of ‘clear’ or ‘gargoyle’ cells.
  • ‘Hurler cells’ relatively large with metachromatically staining cytoplasm with crescent shaped nuclei.
  • Cells not identified with normal H/E stain but with toluidine blue or Alcian blue/ aldehyde fuchsin stains.
  • Should be differentiated from mast cells.

Oral Manifestations:-

hhss

  • Shortening and broadening of the mandible with prominent gonions.
  • Localized areas of bone destruction in the jaws.
  • Teeth may be small and widely spaced.
  • Gingival hyperplasia has been repeatedly described in
    patients with Hurler syndrome.
  • the tongue is also characteristically enlarged.

Laboratory findings:-

  • Elevated levels of mucopolysaccharides in urine.
  • Metachromatic granules or ‘Reily bodies’ often demonstrated in cytoplasm of circulating lymphocytes.

Treatment:-

  • Because of multisystemic involvement in patients with mucopolysaccharidosis type I (MPS I), treatment is multidisciplinary and encompasses both the curative and palliative elements.
  • Corrective surgery may be necessary for patients with mucopolysaccharidosis type I (MPS I) who have joint contractures or foot and hand deformities.

  • Corneal transplants may be required if vision problems become severe.

  • Given the numerous mutations at this genetic locus, identification of which allele or alleles are involved requires referral to medical geneticists for diagnosis and genetic counseling.

References :-

1.SHAFERS’s 8th edition

2.NEVIELLE’S 3rd edition

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