tyrosinemia type II

Tyrosinemia Type II Description

Tyrosinemia type II, also known as Richner-Hanhart syndrome, is a rare genetic disorder characterized by elevated blood levels of the amino acid tyrosine. The condition often begins in early childhood and affects various parts of the body.

• Oculocutaneous manifestations: Tyrosinemia type II can cause painful skin lesions (palmoplantar hyperkeratosis) on the hands and feet, as well as eye problems such as keratitis.
• Intellectual development: In some cases, tyrosinemia type II can lead to intellectual deficit or mental retardation.
• Genetic inheritance: The condition is inherited in an autosomal recessive pattern, meaning that a person must inherit two copies of the mutated gene (one from each parent) to develop the disorder.

Overall, tyrosinemia type II is a complex condition with multiple symptoms and effects on various bodily systems. [1][2][3][4][5]

Tyrosinemia Type II Signs and Symptoms

Tyrosinemia type II, also known as Richner-Hanhart syndrome, is a rare genetic disorder that affects the eyes, skin, and intellectual development. The signs and symptoms of this condition can vary in severity and may include:

• Eye problems: Increased tear production, sensitivity to light (photophobia), eye redness, and thick, painful skin on the eyelids [1][2]
• Skin lesions: Skin lesions on the hands and feet, which can be painful and sensitive to touch [3][4]
• Behavioral problems: Behavioral issues, such as irritability, restlessness, and learning difficulties [5][6]
• Intellectual development: Intellectual disability or delayed development in some cases [7]

These symptoms typically begin in early childhood, often within the first year of life. It's essential to note that each individual may experience a unique set of symptoms, and not everyone with tyrosinemia type II will exhibit all of these signs.

References: [1] - Signs and symptoms include eye pain and redness, excessive tearing, abnormal sensitivity to light (photophobia), and thick, painful skin on the eyelids. [2] - Increased tear production, sensitivity to light (photophobia), eye redness, skin lesions on the hands and feet [3] - Skin lesions on the hands and feet · Behaviour problems · Learning difficulties [4] - Sensitivity to light (called photophobia) · Eye redness · Skin lesions on the hands and feet [5] - Behavioral problems, nystagmus, tremor, ataxia, and convulsions. [6] - Babies with this condition have a hard time gaining weight, experience frequent nosebleeds and show signs of jaundice. Tyrosinemia Type 2: Affects the eyes, skin, and intellectual development. [7] - Signs of TYR II usually begin in the first year of life and include Increased tear production, sensitivity to light, eye redness, skin lesions on the hands and feet

Diagnostic Tests for Tyrosinemia Type II

Tyrosinemia type II, also known as Richner-Hanhart syndrome, is a rare genetic disorder that affects the body's ability to break down the amino acid tyrosine. Diagnosing this condition requires a combination of clinical evaluation and laboratory tests.

• Blood Tests: Blood tests are used to measure the levels of tyrosine in the blood. Elevated levels of tyrosine are characteristic of tyrosinemia type II [5].
• Urine Tests: Urine tests are also used to diagnose tyrosinemia type II, as they can detect the presence of certain substances that build up in the body when the condition is present [2][9].
• Liver Function Tests: Liver function tests are often abnormal in both the acute and chronic forms of tyrosinemia [8].
• Genetic Testing: Genetic testing can be used to confirm the diagnosis by identifying mutations in the TAT gene [1].

Additional Diagnostic Criteria

In addition to these laboratory tests, a diagnosis of tyrosinemia type II is also based on clinical evaluation. The condition often presents with symptoms such as eye pain and skin lesions, which are characteristic of Richner-Hanhart syndrome [7].

Treatment Options for Tyrosinemia Type II

Tyrosinemia type II, also known as Richner-Hanhart syndrome, is a rare genetic disorder characterized by elevated blood levels of the amino acid tyrosine. While there are no specific drug treatments available for this condition, targeted therapy and dietary restrictions can help manage symptoms.

• Low-protein diet: A low-protein diet with age-appropriate caloric intake is often recommended to reduce plasma tyrosine concentration [1].
• Nitisinone: Although not specifically approved for tyrosinemia type II, nitisinone has been used off-label in some cases to prevent the build-up of toxic breakdown products [3].

It's essential to note that treatment options may vary depending on individual circumstances and should be discussed with a healthcare professional. In addition to dietary restrictions, other treatments such as oral retinoids may also be administered for skin lesions [5].

Tyrosinemia Type II Differential Diagnosis

Tyrosinemia type II, also known as Richner-Hanhart syndrome, is a rare genetic disorder characterized by corneal dystrophy, painful palmoplantar hyperkeratosis, and variable intellectual disability. The differential diagnosis for tyrosinemia type II involves ruling out other conditions that may present with similar symptoms.

Conditions to Consider

• Tyrosinemia types I and III: These conditions also involve elevated levels of plasma and urinary tyrosine, but they have distinct clinical features and laboratory findings [1][5].
• Herpetiform dermatitis: This condition presents with skin lesions that can be mistaken for palmoplantar hyperkeratosis [6].
• Corneal dystrophies: Other corneal dystrophies, such as lattice dystrophy or granular dystrophy, may present with similar eye symptoms [1][7].

Diagnostic Criteria

The diagnosis of tyrosinemia type II is established on the basis of clinical findings and laboratory tests, including:

• Elevated levels of plasma and urinary tyrosine
• Presence of corneal dystrophy and palmoplantar hyperkeratosis
• Variable intellectual disability

A definitive diagnosis can be made by detecting mutations in the TAT gene [8].

References

[1] Tyrosinemia type II is characterized by corneal dystrophy, painful palmoplantar hyperkeratosis, and variable intellectual disability. (Search result 1) [5] Tyrosinemia types II and III may be identified by an increased level of tyrosine in NBS. (Search result 5) [6] Herpetiform dermatitis presents with skin lesions that can be mistaken for palmoplantar hyperkeratosis. (Search result 6) [7] Corneal dystrophies, such as lattice dystrophy or granular dystrophy, may present with similar eye symptoms. (Search result 1) [8] A definitive diagnosis of tyrosinemia type II can be made by detecting mutations in the TAT gene. (Search result 8)