Department of Dermatology, and Reference Centre for Genodermatoses and Rare Skin Diseases (MAGEC), Université Paris Descartes-Paris Cité, INSERM U1163, Institut Imagine, APHP, Hôpital Universitaire Necker-Enfants Malades, 75015 Paris, France.
Department of Dermatology, Reference Centre for Genodermatoses and Rare Skin Diseases, INSERM U1312, Bordeaux University Hospital, 33000 Bordeaux, France.
Genes (Basel). 2022 Nov 23;13(12):2198. doi: 10.3390/genes13122198.
Albinism is a genetic disorder, present worldwide, caused by mutations in genes affecting melanin production or transport in the skin, hair and eyes. To date, mutations in at least 20 different genes have been identified. Oculo-cutaneous Albinism type IV (OCA4) is the most frequent form in Asia but has been reported in all populations, including Europeans. Little is known about the genotype-phenotype correlation. We identified two main phenotypes via the analysis of 30 OCA4 patients with a molecularly proven diagnosis. The first, found in 20 patients, is clinically indistinguishable from the classical OCA1 phenotype. The genotype-to-phenotype correlation suggests that this phenotype is associated with homozygous or compound heterozygous nonsense or deletion variants with frameshift leading to translation interruption in the gene. The second phenotype, found in 10 patients, is characterized by very mild hypopigmentation of the hair (light brown or even dark hair) and skin that is similar to the general population. In this group, visual acuity is variable, but it can be subnormal, foveal hypoplasia can be low grade or even normal, and nystagmus may be lacking. These mild to moderate phenotypes are associated with at least one missense mutation in .
白化病是一种遗传疾病，存在于世界各地，由影响皮肤、头发和眼睛中黑色素生成或运输的基因突变为导。迄今为止，已经确定了至少 20 种不同基因的突变。眼皮肤白化病 IV 型（OCA4）是亚洲最常见的形式，但已在包括欧洲人在内的所有人群中报告过。关于基因型与表型的相关性知之甚少。我们通过对 30 名经分子证实诊断的 OCA4 患者进行分析，确定了两种主要表型。第一种表型存在于 20 名患者中，与经典的 OCA1 表型在临床上无法区分。基因型与表型的相关性表明，这种表型与导致基因翻译中断的无义或缺失变异的纯合子或复合杂合子相关，这些变异会导致移码。第二种表型存在于 10 名患者中，其特征是头发（浅棕色甚至深色头发）和皮肤的色素沉着非常轻微，类似于一般人群。在这一组中，视力可变，但可能低于正常水平，黄斑发育不良可能为低等级甚至正常，眼球震颤可能缺乏。这些轻度至中度表型与至少一种错义突变相关，这些突变位于基因中。
