Jiang Anna, Liang Licong, She Kaiqin, Lu Fang
Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
Front Med (Lausanne). 2024 Aug 29;11:1369884. doi: 10.3389/fmed.2024.1369884. eCollection 2024.
Multiple pigmented epithelial cysts at the edge of pupils, that is, iris flocculi, in both eyes, are rare ocular diseases. It has been demonstrated that this disease can be attributed to mutations in the smooth muscle α-actin 2 () gene, which mainly affects the function of smooth muscle cells (SMCs). SMCs are components of the iris, aorta, and several other systemic organs. In addition, iris flocculi are strongly correlated with familial thoracic aortic aneurysm and dissection (TAAD), which is caused by the mutation of amino acid 149 in the gene.
A 6-month-old Chinese boy was found to have iris flocculi during ocular fundus screening for premature infants. His mother, a 30-year-old Chinese woman with a history of aortic dissection, underwent an ophthalmic examination and was found to have iris flocculi. Whole exome sequencing revealed a heterozygous c.445C > T (p. Arg149Cys) mutation in in both the boy and his mother. After his family history was traced, the boy's grandfather was diagnosed with similar iris flocculi. Due to the absence of any ocular complications caused by iris flocculi in the cases, no special treatment was given, and regular follow-up was recommended.
We reported one case of familial iris flocculi caused by a heterozygous missense mutation in (p. Arg149Cys) and presented multimodal optical images of both the iris and fundus in three consecutive generations. This case report enriched the clinical features of retinal vasculature and macula associated with the mutation in the amino acid 149 of the gene.
双眼瞳孔边缘出现多个色素上皮囊肿，即虹膜絮状赘生物，是一种罕见的眼部疾病。已证明该疾病可归因于平滑肌α - 肌动蛋白2（）基因的突变，该基因主要影响平滑肌细胞（SMC）的功能。SMC是虹膜、主动脉和其他几个全身器官的组成部分。此外，虹膜絮状赘生物与家族性胸主动脉瘤和夹层（TAAD）密切相关，后者是由基因中第149位氨基酸突变引起的。
一名6个月大的中国男婴在早产儿眼底筛查中被发现有虹膜絮状赘生物。他的母亲，一名30岁有主动脉夹层病史的中国女性，接受眼科检查后也被发现有虹膜絮状赘生物。全外显子组测序显示该男婴及其母亲的基因均存在杂合的c.445C＞T（p.Arg149Cys）突变。追溯其家族病史后，该男婴的祖父被诊断出有类似的虹膜絮状赘生物。由于这些病例中虹膜絮状赘生物未引起任何眼部并发症，因此未给予特殊治疗，建议定期随访。
我们报告了一例由基因杂合错义突变（p.Arg149Cys）引起的家族性虹膜絮状赘生物病例，并展示了连续三代人的虹膜和眼底的多模态光学图像。该病例报告丰富了与基因第149位氨基酸突变相关的视网膜血管和黄斑的临床特征。
