PDF(Pubmed)
Abstract：
We present a case involving a patient whose clinical phenotype aligns with oculocutaneous albinism (OCA), yet exhibits a complex genotype primarily characterized by variants of unknown significance (VUS). An 11-year-old boy manifested iris hypopigmentation and translucency, pronounced photophobia, diminished visual acuity and stereopsis, nystagmus, reduced pigmentation of the retina, and foveal hypoplasia. Genetic testing was performed. A heterozygous missense VUS CAPN5 c.230A>G, p.(Gln77Arg), a heterozygous missense VUS TYR c.1307G>C, p.(Gly436Ala), and a heterozygous missense variant TYR c.1205G>A, p.(Arg402Gln) which was classified as a risk factor, were identified. We hypothesized that the TYR c.1307G>C, p.(Gly436Ala) variant is in genetic disequilibrium with the TYR c.1205G>A, p.(Arg402Gln) variant leading to deficient expression of melanogenic enzymes in retinal cells, resulting in the manifestation of mild OCA. Additionally, this study represents the case where we did not detect chiasmal misrouting in visual evoked potentials, nor did we observe a shift in the distribution of ganglion cell thickness from a temporal to a central position. Moreover, our patient\'s case supports the probable benign nature of the CAPN5 c.230A>G, p.(Gln77Arg) variant.
摘要：
我们介绍了一例涉及临床表型与眼皮肤白化病（OCA）相符的患者，但表现出复杂的基因型，主要特征是未知意义的变异（VUS）。一个11岁的男孩表现出虹膜色素减退和半透明，明显的畏光，视力和立体视觉减弱，眼球震颤,视网膜色素沉着减少，和中央凹发育不全。进行基因检测。杂合错义VUSCAPN5c.230A>G，p.(Gln77Arg),杂合错义VUSTYRc.1307G>C，p.（Gly436Ala），和一个杂合错义变体TYRc.120G>A，p.(Arg402Gln)被归类为风险因素，已确定。我们假设TYRc.1307G>C，p。（Gly436Ala）变体处于遗传不平衡状态，TYRc.120G>A，p。（Arg402Gln）变体导致视网膜细胞中黑色素生成酶的表达不足，导致轻度OCA的表现。此外,这项研究代表了我们没有在视觉诱发电位中检测到chiasmal错误路由的情况，我们也没有观察到神经节细胞厚度从时间位置到中心位置的分布变化。此外，我们患者的病例支持CAPN5c.230A>G的可能的良性性质，p.(Gln77Arg)变体。
