Richner Hanhart syndrome

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Richner Hanhart syndrome, also called Richner syndrome or Hanhart syndrome,^[1] is a rare autosomal recessive disorder due to a deficiency of the enzyme tyrosine aminotransferase.

1 Symptoms
2 Pathophysiology
3 Treatment
4 Eponym
5 References
6 External links

[edit] Symptoms

Symptoms of Richner Hanhart syndrome include ocular lesions and palmo-plantar hyperkeratosis. Eye symptoms develop from two weeks of age and include redness, lacrimation and photophobia. Tyrosine crystals in the cornea cause corneal clouding with corneal opacities, corneal scarring and dendritic ulcers. In the first year of life, the patient will show skin conditions like nonpruritic hyperkeratotic papules and plaques on the palms and soles. Mental retardation affects less than 50% of all cases. Patients will have high levels of tyrosine in the urine.

[edit] Pathophysiology

Richner Hanhart syndrome has an autosomal recessive pattern of inheritance.

Richner Hanhart syndrome is caused by a deficiency of the enzyme tyrosine amino transferase (TAT). TAT is located on chromosome 16q22.1-q 22.3.

[edit] Treatment

Dietary restriction of amino acids phenylalanine and tyrosine is an effective treatment for people with Richner Hanhart Syndrome.

[edit] Eponym

It is named for Ernst Hanhart and Hermann Richner, who independently reported it in 1947 and 1938, respectively.

[edit] References

^ Hanhart E (1950) "Über die Kombination von Peromelia mit Mikrognathia, ein neues Syndrom beim Menschen, entsprechend der Akroteriasis congenita von Wriedt und Mohr beim Rinde". Archiv der Julius Klaus-Stiftung für Vererbungsforschung, Sozialanthropologie und Rassenhygiene, Zürich. 25: 531-544.