Oculocutaneous albinism

نویسندگان

  • Karen Grønskov
  • Jakob Ek
  • Karen Brondum-Nielsen
چکیده

Oculocutaneous albinism (OCA) is a group of inherited disorders of melanin biosynthesis characterized by a generalized reduction in pigmentation of hair, skin and eyes. The prevalence of all forms of albinism varies considerably worldwide and has been estimated at approximately 1/17,000, suggesting that about 1 in 70 people carry a gene for OCA. The clinical spectrum of OCA ranges, with OCA1A being the most severe type with a complete lack of melanin production throughout life, while the milder forms OCA1B, OCA2, OCA3 and OCA4 show some pigment accumulation over time. Clinical manifestations include various degrees of congenital nystagmus, iris hypopigmentation and translucency, reduced pigmentation of the retinal pigment epithelium, foveal hypoplasia, reduced visual acuity usually (20/60 to 20/400) and refractive errors, color vision impairment and prominent photophobia. Misrouting of the optic nerves is a characteristic finding, resulting in strabismus and reduced stereoscopic vision. The degree of skin and hair hypopigmentation varies with the type of OCA. The incidence of skin cancer may be increased. All four types of OCA are inherited as autosomal recessive disorders. At least four genes are responsible for the different types of the disease (TYR, OCA2, TYRP1 and MATP). Diagnosis is based on clinical findings of hypopigmentation of the skin and hair, in addition to the characteristic ocular symptoms. Due to the clinical overlap between the OCA forms, molecular diagnosis is necessary to establish the gene defect and OCA subtype. Molecular genetic testing of TYR and OCA2 is available on a clinical basis, while, at present, analysis of TYRP1 and MATP is on research basis only. Differential diagnosis includes ocular albinism, Hermansky-Pudlak syndrome, Chediak-Higashi syndrome, Griscelli syndrome, and Waardenburg syndrome type II. Carrier detection and prenatal diagnosis are possible when the disease causing mutations have been identified in the family. Glasses (possibly bifocals) and dark glasses or photocromic lenses may offer sufficient help for reduced visual activity and photophobia. Correction of strabismus and nystagmus is necessary and sunscreens are recommended. Regular skin checks for early detection of skin cancer should be offered. Persons with OCA have normal lifespan, development, intelligence and fertility.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

A Unique Albino Village of Bhatti Tribe in Rural Sindh, Pakistan, with Oculocutaneous albinism Manifestations: An Epidemiological Study

Background: Oculocutaneous albinism is a disease with an autosomal recessive inheritance pattern in most cases. People with Oculocutaneous albinism face many health, psychological and financial issues. In this study, we report a unique village of Bhatti tribe in Jacobabad District, Pakistan, in which 40 children and adults with albinism live. The aim of this study was to observe the patte...

متن کامل

Oculocutaneous albinism type 2

Oculocutaneous albinism represents a group of inherited skin disorders characterized by a generalized reduction of cutaneous, ocular, and pilar pigmentation from the time of birth. Oculocutaneous albinism types I and II are the most common, with several other types described. A defect in the melanin synthesis pathway, resulting in reduced formation of melanin, is responsible for oculocutaneous ...

متن کامل

Mutational Analysis of Oculocutaneous Albinism: A Compact Review

Oculocutaneous albinism (OCA) is an autosomal recessive disorder caused by either complete lack of or a reduction of melanin biosynthesis in the melanocytes. The OCA1A is the most severe type with a complete lack of melanin production throughout life, while the milder forms OCA1B, OCA2, OCA3, and OCA4 show some pigment accumulation over time. Mutations in TYR, OCA2, TYRP1, and SLC45A2 are mainl...

متن کامل

Childhood autism in a 13 year old boy with oculocutaneous albinism: a case report

INTRODUCTION Hypomelanotic skin disorders like tuberous sclerosis and hypomelanosis of Ito that present with multiple systemic manifestations have been reported in association with childhood autism. Oculocutaneous albinism is another hypomelanotic skin disorder that rarely presents with multiple systemic manifestations. It is infrequently reported in association with childhood autism when compa...

متن کامل

Synchrony of oculocutaneous albinism, the Prader-Willi syndrome, and a normal karyotype.

A Chinese girl with oculocutaneous albinism has the Prader-Willi syndrome and a normal karyotype. This association emphasises the importance of further molecular study of the 15(q12) region of the genome in the search for the locus of an albinism gene.

متن کامل

Genetic Analysis of Oculocutaneous Albinism Type1A (OCA1A) in an Iranian Family

BACKGROUND Oculocutaneous albinism type1 (OCA1) is characterized by the absence of melanin pigmentation. The mutation on TYR gene makes OCA1 as an autosomal recessive genetic disorder. In this study, we delineated the genetic analysis of an Iranian family with four members affected with OCA1. METHODS Clinical exams and paraclinical test were performed for all patients of the case family, also...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Orphanet Journal of Rare Diseases

دوره 2  شماره 

صفحات  -

تاریخ انتشار 2007