Laboratoire Maladies Rares, Génétique et Métabolisme, Bordeaux University INSERM U1211, Bordeaux, France.
Infirmerie Hôpital Militaire, Bamako, Mali.
Pigment Cell Melanoma Res. 2024 Nov;37(6):752-761. doi: 10.1111/pcmr.13175. Epub 2024 May 9.
Albinism is a phenotypically and genetically heterogeneous condition characterized by a variable degree of hypopigmentation and by ocular features leading to reduced visual acuity. Whereas numerous genotypic studies have been conducted throughout the world, very little is known about the genotypic spectrum of albinism in Africa and especially in sub-Saharan Western Africa. Here we report the analysis of all known albinism genes in a series a 23 patients originating from Mali. Four were diagnosed with OCA 1 (oculocutaneous albinism type 1), 17 with OCA 2, and two with OCA 4. OCA2 variant NM_000275.3:c.819_822delinsGGTC was most frequently encountered. Four novel variants were identified (two in TYR, two in OCA2). A deep intronic variant was found to alter splicing of the OCA2 RNA by inclusion of a pseudo exon. Of note, the OCA2 exon 7 deletion commonly found in eastern, central, and southern Africa was absent from this series. African patients with OCA 1 and OCA 4 had only been reported twice and once, respectively, in previous publications. This study constitutes the first report of the genotypic spectrum of albinism in a western sub-Saharan country.
白化病是一种表型和基因型异质性疾病，其特征是色素沉着程度不同，以及导致视力下降的眼部特征。虽然世界各地已经进行了许多基因研究，但对于非洲，特别是撒哈拉以南的西非的白化病的基因谱知之甚少。在这里，我们报告了对来自马里的 23 名患者的一系列已知白化病基因的分析。其中 4 名被诊断为 OCA1（眼皮肤白化病 1 型），17 名被诊断为 OCA2，2 名被诊断为 OCA4。最常见的 OCA2 变体 NM_000275.3：c.819_822delinsGGTC。鉴定出了四个新的变体（两个在 TYR，两个在 OCA2）。一个深内含子变体通过包含假外显子改变了 OCA2 RNA 的剪接。值得注意的是，该系列中没有发现常见于东部、中部和南部非洲的 OCA2 外显子 7 缺失。以前的出版物中仅报道过两次和一次非洲 OCA1 和 OCA4 患者。本研究首次报道了撒哈拉以南西部国家白化病的基因型谱。
