Albinism! :D
Partial : hypomelanosis
Total: amelanism or amelanosis
Cause?
The principal gene which results in albinism
prevents the body from making the usual
amounts of the pigment melanin.
melanin- found in plants&animals. They are
derivatives of the amino acid tyrosine
OPPOSITE:
Melanism- increased amount of dark
pigmentation
Albinism appears in different forms and may
be inherited by one of several modes:
autosomal recessive, autosomal dominant,
or X-linked.
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This figure shows the coding region of the MATP gene (530 amino acids). The red is
the coding region and the yellow boxes are the putative transmembrane regions.
Missense mutations are on the top and nonsense, frameshift and splice site
mutations are on the bottom.
GenBank Accession for mRNA sequence (AF172849).
2 Types!
oculocutaneous albinism [4 types]
A form of albinism involving the eyes
("oculo-"), skin ("-cutaneous"), and the hair
as well.
ocular albinism
is a form of albinism which, in contrast to
oculocutaneous albinism, presents
primarily in the eyes.
Albinism
Humans with albinism commonly have vision
problems and need sun protection..
Tanzia http://news.bbc.co.uk/2/hi/africa/7518049.stm
Tyrosinase Related Protein-1 Gene
Mutations Associated with Oculocutaneous
Albinism type 3
This figure shows the coding region of the tyrosinase related
protein-1 gene (537 amino acids). Light blue is the signal
peptide, green is the putative metal ion binding regions,
orange is the transmembrane region. White circles are the
location of cystein residues and the EGF is a epidermal
growth factor-like region. Missense mutations are on the
top and nonsense, frameshift and splice site mutations
are on the bottom.
Frequency
Albinism usually occurs with equal frequency in both
genders. An exception to this is ocular albinism,
because it is passed on to offspring through X-linked
inheritance. Thus, males more frequently have ocular
albinism as they do not have a second X chromosome.
Those with oculocutaneous albinism may experience
abnormal flickering eye movements (nystagmus) and
sensitivity to bright light. There may be other eye
problems as well, including poor vision and crossed or
"lazy" eyes (strabismus).
About 1 in 17,000 human beings has some type of
albinism, although up to 1 in 70 is a carrier of albinism
genes
Phenotypes!
Animals with albinism occasionally have red eyes
due to the retinal blood vessels showing through
from under the eye. (not enough pigment)
However red eyes for humans are rare. The
human eye is quite large and thus produces
enough pigment to lend opacity to the eye. So,
the iris pale blue. However, there are cases in
which the eyes of an albinistic person appear
red or purple, depending on the amount of
pigment present.
Works Cited!
"Albinism." Wikipedia. N.p., 12 Nov. 2009. Web. 12 Nov. 2009. <http://en.wikipedia.org/wiki/
Albino>.
Alan, Rick. "Albinism." Aurora Health Care. N.p., 12 Nov. 2009. Web. 12 Nov. 2009.
<http://www.aurorahealthcare.org/yourhealth/healthgate/
getcontent.asp?URLhealthgate=%2222573.html%22>.
"Welcome to the Albinism Database." Albinism Database. University of Minnesota, n.d. Web. 12 Nov.
2009. <http://albinism.med.umn.edu/>.
“Oculocutaneous Albinism." Wikipedia. N.p., 12 Nov. 2009. Web. 12 Nov. 2009.
<http://en.wikipedia.org/wiki/Oculocutaneous_albinism>.
"Living in fear: Tanzania's albinos." BBC News. N.p., 21 July 2008. Web. 12 Nov. 2009.
<http://news.bbc.co.uk/2/hi/africa/7518049.stm>.
"Albinism." Answers. N.p., 12 Nov. 2009. Web. 12 Nov. 2009. <http://www.answers.com/topic/
becker-s-muscular-dystrophy>.