Background

5.2% of people are carriers for at least two recessive diseases; it can be concluded that a much smaller proportion develop these conditions as two mutated copies of a gene must be present for the disease to manifest clinically.

Case presentation

We present a 38-year-old Caucasian female affected by two autosomal recessive disorders which can affect the eyes, pseudoxanthoma elasticum (PXE) and retinitis pigmentosa (RP). PXE is an autosomal recessive disorder caused by mutations in ABCC6, affecting 1:25 000 to 1:100 000 people; its classical features involve the dermatological, ophthalmological and cardiovascular systems. Our patient presented with dermatological features of PXE and ophthalmological features of RP. RP presents with significant locus heterogeneity; our patient had biallelic mutations in USH2A.

Conclusions

This report highlights an interesting case of two unrelated autosomal recessive diseases presenting in one person, both of which have the potential to manifest with ophthalmological symptoms and signs. Though it is likely that only one condition has caused the ophthalmological findings in this case, it raises the question of how we can distinguish the causative disease when two conditions are present that have a shared target organ.

中文翻译：

---

弹性假黄瘤和色素性视网膜炎：对隐性疾病的双重诊断具有眼科后果。

背景

5.2％的人是至少两种隐性疾病的携带者；可以得出结论，由于必须存在基因的两个突变拷贝才能使疾病在临床上表现出来，因此发展这些疾病的比例要小得多。

案例介绍

我们介绍了一名38岁的白人女性，患有两种常染色体隐性遗传疾病，可能会影响眼睛，弹性假黄瘤（PXE）和色素性视网膜炎（RP）。PXE是一种由ABCC6突变引起的常染色体隐性遗传疾病，影响了1:25 000至1：100 000的人群；它的经典特征涉及皮肤，眼科和心血管系统。我们的患者表现出PXE的皮肤病学特征和RP的眼科特征。RP具有明显的基因座异质性。我们的患者在USH2A中存在双等位基因突变。

结论

该报告突出了一个有趣的案例，即一个人出现了两种不相关的常染色体隐性遗传疾病，这两种疾病都有可能表现出眼科症状和体征。尽管在这种情况下很可能只有一种情况引起了眼科检查，但它提出了一个问题，即当存在两个目标器官共享的情况时，我们如何区分致病性疾病。