Hunter's disease

from Wikipedia, the free encyclopedia
Classification according to ICD-10
E76.1 Mucopolysaccharidosis,
Hunter type II disease
ICD-10 online (WHO version 2019)

The Hunter syndrome (also Mucopolysaccharidosis Type II called) is an X-linked - recessive inherited metabolic disease . It belongs to the mucopolysaccharidoses (MPS), a group of diseases in which the lysosomal breakdown of mucopolysaccharides is disturbed.

frequency

Due to the X-linked inheritance, almost only boys are affected by the disease. One case of Hunter syndrome is one out of around 156,000 births. In Germany this is around 4–5 new cases per year.

root cause

Hunter's disease is caused by a defective gene on the X chromosome (Xq27.3-q28), which codes for iduronate 2 sulfatase . The mutation disrupts the breakdown of dermatan and heparan sulfate.

Symptoms

The appearance ranges from severe forms with mental retardation (formerly type A) to very mild forms with little or no mental development delay (formerly type B). The transitions are fluid.

Specific for MPS type II are skin symptoms with pale, nodular thickenings, usually grouped together (“peau d'orange”).

Other symptoms are

  • Facial changes: thick eyebrows, flat, sunken bridge of the nose, fleshy, broad lips, enlarged tongue, prognathy .
  • deep and hoarse voice
  • Cardiac involvement up to heart failure
  • Middle ear and inner ear hearing loss
  • Optic atrophy
  • early onset, progressive joint contractures,
  • distended abdomen from developing hepatosplenomegaly
  • Umbilical hernia
  • Growth retardation .
  • Severely affected patients can develop tetraspasticity with swallowing and breathing disorders after a phase of aggressiveness and eretics, gross motor disorders with unsteady gait and frequent falling .
  • Skeletal changes (dysostosis multiplex congenita)

diagnosis

The diagnosis is established by the increased excretion of mucopolysaccharides (dermatan and heparan sulfate) in the urine (electrophoresis). The defective enzyme is also determined in leukocytes or fibroblasts . A molecular genetic analysis is possible, as is a prenatal diagnosis in amnion cells or chorionic villi (cells).

therapy

A causal treatment is not available. The possibility of a stem cell transplant is possible in individual cases. Idursulfase (Elaprase) was approved as the first enzyme replacement therapy in Europe in January 2007 .

See also Gaucher's disease and Hunter-McAlpine craniosynostosis .

Individual evidence

  1. http://www.ratschlag24.com/index.php/morbus-hunter-erste-enzymersatztherapie-zugelassen-_57825/