Zühlke C, Stell A, Käsmann-Kellner B
Institut für Humangenetik, Universität Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Deutschland.
Ophthalmologe. 2007 Aug;104(8):674-80. doi: 10.1007/s00347-007-1590-1.
Albinism comprises a heterogeneous group of nonprogressive genetic disorders characterized by the absence of pigmentation in the skin, hair, and/or eyes. Hypopigmentation or complete lack of pigmentation is caused by an enzyme deficiency involving the production, metabolism, or distribution of melanin. Clinically, oculocutaneous and ocular types, as well as syndromes associated with albinism resulting from mutations in at least 14 genes, are distinguishable. Most frequent is oculocutaneous albinism (OCA), which is subdivided nowadays into four forms, OCA 1-OCA 4. OCA is inherited as an autosomal recessive trait. Clinical differentiation of OCA types is difficult due to the observed range of phenotypic variation. Thus, genetic analysis may be helpful with respect to a precise diagnosis. Sequencing of the four genes associated with OCA detects variations in approximately 60-70% of German patients with albinism. The majority of German patients are affected by OCA 1 resulting from mutations in the gene for tyrosinase, the key enzyme in the synthesis of melanin pigment. Worldwide, OCA2 is the most frequent form of albinism.
白化病是一组异质性的非进行性遗传性疾病，其特征是皮肤、毛发和/或眼睛缺乏色素沉着。色素沉着不足或完全缺乏色素沉着是由涉及黑色素产生、代谢或分布的酶缺乏引起的。临床上，眼皮肤型和眼型白化病，以及由至少14个基因突变导致的与白化病相关的综合征是可区分的。最常见的是眼皮肤白化病（OCA），目前可细分为四种类型，即OCA 1 - OCA 4。OCA以常染色体隐性性状遗传。由于观察到的表型变异范围，OCA各类型的临床鉴别较为困难。因此，基因分析可能有助于精确诊断。对与OCA相关的四个基因进行测序，在大约60 - 70%的德国白化病患者中检测到变异。大多数德国患者受OCA 1影响，这是由黑色素合成关键酶酪氨酸酶基因突变所致。在全球范围内，OCA2是最常见的白化病类型。
