This video shows the eye of a patient with oculocutaneous albinism. The deficiency of melanin pigment in the iris shows up as transillumination in slit lamp examination. The edge of the lens and the ciliary processes are seen through the iris. Other ocular features include nystagmus, foveal hypoplasia, refractive error and decreased visual acuity. The albinotic fundus charecteristically shows deficient pigment and is orangish with choroidal vessels seen through.
References
| 1. | Basic and Clinical Science Course. American Academy of Ophthalmology. 2006-2007. | |
| 2. | Duane's Ophthalmology 1997. CD-ROM Edition. |
1 Comment
Dear Dr. Karanth: Thanks so much for the post on albinism. As someone with albinism I found it especially interesting. I am also the Vice President and Director of Outreach for the Hermansky-Pudlak Syndrome Network. HPS, as you may know, is a rare type of albinism that also involves a bleeding disorder and in some gene mutations, pulmonary fibrosis. We keep a patient registry of people from all over the world with HPS. We currently have nine people on our registry of Indian background - all but one adopted from India. We had one member from India, however, he passed away last year. I'm aware of at least three others mentioned in the medical literature.
I only mention this because very often people with HPS go undiagnosed because there is so little awareness of the syndrome. Because of the bleeding issues (which can be treated) it can be important for people to know.
Here's a paper recently published about several cases found here. Thanks so much for your educational work. We are very anxious to find other cases of HPS in India.
Hermansky–Pudlak syndrome type 1 in patients of Indian descent
Lisa M. Vincenta, , , David Adamsa, Richard A. Hessa, Shira G. Zieglera, Ekaterini Tsiloub, Gretchen Golasa, c, Kevin J. O’Briena, c, James G. Whited, Marjan Huizinga and William A. Gahla, c
aSection on Human Biochemical Genetics, Medical Genetics Branch, NHGRI, NIH, 10 Center Drive, Bldg. 10, Rm 10C107, MSC1851, Bethesda, MD 20892-1851, USA
bOphthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
cIntramural Office of Rare Diseases, Office of the Director, NIH, Bethesda, MD 20892, USA
dDepartment of Laboratory Medicine, University of Minnesota, Minneapolis, USA
Received 11 February 2009; revised 26 March 2009; accepted 27 March 2009. Available online 2 April 2009.
Abstract
Hermansky–Pudlak syndrome (HPS) develops from defects in the biogenesis and/or function of lysosome-related organelles essential to membrane and protein trafficking. Of the eight known human subtypes, only HPS-1 and HPS-4 develop pulmonary fibrosis in addition to the general clinical manifestations of oculocutaneous albinism and bleeding diathesis. We identified HPS-1 in three unrelated patients from different regions of India, who presented with iris transillumination, pale fundi, hypopigmentation, nystagmus, decreased visual acuity, and a bleeding diathesis. Two of these patients carried the homozygous mutation c.398+5G>A (IVS5+5G>A) in HPS1, resulting in skipping of exon 5 in HPS1 mRNA. The third patient carried a novel homozygous c.988−1G>T mutation that resulted in in-frame skipping of HPS1 exon 12 and removes 56 amino acids from the HPS1 protein. Given the discovery of HPS-1 in an ethnic group where oculocutaneous albinism (OCA) is highly prevalent, it is possible that HPS in India is under-diagnosed. We recommend that unconfirmed OCA patients in this ethic group be considered for mutational screening of known HPS genes, in particular c.398+5G>A and c.980−1G>T, to ensure that patients can be monitored and treated for clinical complications unique to HPS.
Molecular Genetics and Metabolism
Volume 97, Issue 3, July 2009, Pages 227-233
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