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Albinism in this form is limited to the mere presence of signs of ocular albinism.
Eye colour and skin are in the normal range but lighter than unaffected siblings.
Tyrosinase activity of the hair bulb is positive.
There are at least three known forms of this disease (OA1, OA2, OA3).
OA1 is a recessive X-linked form, it manifests itself fully only in hemizigous males.
In heterozygous female carriers it can be present an abnormal pigmentation of the retina or the iris. Skin and ocular melanocytes contain giant melanosomes.
The gene involved is located on the short arm of the X chromosome.
Only recently it's been understood that the OA2 form could be a variant of the OA1.
The OA3 form is seen nowadays as a moderate variant of Oculocutaneous albinism type 2.
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Father
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X
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Y
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Mother
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X
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Carrier Daughter
XX
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Affected Son
XY
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X
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Healthy Daughter
XX
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Healthy Son
XY
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