Bietti crystalline dystrophy (BCD) is a rare heritable retinal disease characterized by crystal deposition primarily in the retina. It is associated with atrophy of the retinal pigment epithelium (RPE) and is caused by variants in CYP4V2, which encodes a cytochrome P450 hemethiolate protein superfamily member. CYP4V2 is involved in the selective hydrolysis of saturated medium chain fatty acids, and patients with BCD demonstrate abnormalities in fatty acid metabolism, including abnormal lipid profiles and the accumulation of the pathogenic crystals within the RPE, which leads to the visual pathologies characteristic of BCD. However, the precise identity of the crystals is currently unknown, and BCD has no established extraocular manifestations. Here, we report granulomatous hepatitis associated with abundant diffuse crystalline clefts in the hepatic parenchyma in 3 patients with retinal dystrophy and dyslipidemia: 2 with pathogenic CYP4V2 variants and 1 patient with clinical ophthalmologic findings suggestive of BCD but without available genetic testing. The unique and striking histologic features unifying the liver biopsies in all 3 patients strongly support a process related to abnormal fatty acid metabolism underlying the genetic disease of BCD, expanding the spectrum of BCD and shedding light on the importance of CYP4V2 in systemic fatty acid metabolism.

中文翻译：

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与 Bietti 结晶营养不良相关的结晶性肝病：脂肪酸代谢紊乱的显着表现。


Bietti 晶体营养不良症 (BCD) 是一种罕见的遗传性视网膜疾病，其特征是晶体主要沉积在视网膜中。它与视网膜色素上皮 (RPE) 萎缩有关，由 CYP4V2 变异引起，CYP4V2 编码细胞色素 P450 羟甲基硫醇盐蛋白超家族成员。 CYP4V2参与饱和中链脂肪酸的选择性水解，BCD患者表现出脂肪酸代谢异常，包括脂质谱异常和RPE内致病晶体的积累，从而导致BCD特征性的视觉病理。然而，目前尚不清楚晶体的确切身份，并且 BCD 还没有确定的眼外表现。在这里，我们报告了 3 名视网膜营养不良和血脂异常患者的肉芽肿性肝炎，其肝实质中存在大量弥漫性结晶裂隙：2 名患者具有致病性 CYP4V2 变异，1 名患者的临床眼科结果提示 BCD，但没有可用的基因检测。所有 3 名患者的肝活检均具有独特而显着的组织学特征，有力地支持了 BCD 遗传病中与脂肪酸代谢异常相关的过程，扩大了 BCD 的谱系，并揭示了 CYP4V2 在全身脂肪酸代谢中的重要性。