Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
12 Cards in this Set
- Front
- Back
Richner-Hanhart Syndrome
|
|
|
Synonym
|
Tyrosinemia type II
|
|
Inheritance
|
Autosomal recessive; tyrosine aminotransferase gene on 16q22.1 q22
|
|
Prenatal
|
Amniocentesis: tyrosine aminotransferase assay
DNA analysis available if defect known in family |
|
Incidence
|
Less than 50 cases reported; increased in patients with Italian ancestry; M=F
|
|
Age at Presentation
|
First few months of life (eye findings precede skin findings)
|
|
Pathogenesis
|
Mutations in the tyrosine aminotransferase gene on I 6q leads to deficiency of the hepatic enzyme with accumulation of tyrosine in all tissues; tyrosine crystals in corneal epithelium are thought to induce an inflammatory response; tyrosine may stimulate microtubule assembly
|
|
Clinical
|
Skin
Focal (weight bearing plantar surfaces, hypothenar or thenar emminences, finger-tips) or diffuse palmoplantar keratoderma; with/without pain with impaired ambulation, erosions, bullae, erythema; Hyperkeratotic plaques on elbows, knees Eyes Severe keratitis with photophobia, corneal ulceration, neovascularization, and Blindness Central Nervous System With/without mental retardation |
|
D/Dx
|
Other forms of PPK
Herpetic keratitis |
|
Lab
|
Increased plasma tyrosine levels
Increased urinary tyrosine metabolites |
|
Management
|
Referral to nutrition ist low phenylalanine/low tyrosine diet
Referral to dermatologist topical therapy, oral retinoids Referral to ophthalmologist |
|
Prognosis
|
If dietetic intervention made early enough, can prevent cutaneous and ocular complications; mental retardation may not respond to diet
|