Hanhart syndrome

Richner Hanhart Syndrome, also called Richner Syndrome and Hanhart Syndrome, is a rare autosomal recessive disorder due to a deficiency in enzyme tyrosine amino transferase. It is named for Ernst Hanhart and Hermann Richner, who independently reported it in 1947 and 1938, respectively.

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 coneal 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.

Genetics
Richner Hanhart Syndrome occurs from a deficiency of the enzyme tyrosine amino transferase (TAT). TAT is located on chromosome 16q22.1-q 22.3.

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