Synthesis of melanin.
Melanin is synthesized from:
| A |
Tryptophan |
|
| B |
Tyrosine |
|
| C |
Methionine |
|
| D |
Taurine |
Melanin is synthesized from:
| A |
Tryptophan |
|
| B |
Tyrosine |
|
| C |
Methionine |
|
| D |
Taurine |
All of the following are true regarding albinism except:
March 2009
| A |
Autosomal recessive condition |
|
| B |
Normal production of melanin |
|
| C |
Tyrosinase positive are usually less severe |
|
| D |
Prone to develop squamous cell carcinoma of skin |
All of the following are true regarding albinism except:
March 2009
| A |
Autosomal recessive condition |
|
| B |
Normal production of melanin |
|
| C |
Tyrosinase positive are usually less severe |
|
| D |
Prone to develop squamous cell carcinoma of skin |
Ans. B: Normal production of melanin
Oculocutaneous albinism is inherited as an autosomal recessive trait.
Ocular albinism results from mutation in a gene on the X chromosome, which maps to band Xp22.3-22.2 and is inherited as an X-linked recessive trait.
Two main variants:
Tyrosinase positive are usually less severe whereas tyrosinase negative are more severe
Molecular defect is absent/sparse production of melanin.
Pateint presents with total absence of melanin in skin, hair and eyes.
They are prone to develop squamous cell carcinoma of skin induced by ultraviolet rays, which develops on photo-exposed parts due to lack of protective melanin.
