Birt-Hogg-Dubé syndrome associated with chorioretinopathy and nyctalopia: a case report and review of the literature

• Published in: Ophthalmic genetics 2023-04, Vol.44 (2), p.175-181
• Main Authors: Konstantinou, Eleni K, Shaikh, Noreen, Ramsey, David J
• Format: Article
• Language: English
• Subjects: Birt-Hogg-Dube Syndrome - complications; Central Serous Chorioretinopathy - complications; Female; Humans; Middle Aged; Night Blindness - complications
• ISSN: 1381-6810; 1744-5094
• DOI: 10.1080/13816810.2021.1961281

To report a rare case of Birt-Hogg-Dubé Syndrome (BHD) with progressive chorioretinopathy. Case report. A 55-year-old woman presented with longstanding nyctalopia attributed to a congenital retinal dystrophy, but no prior genetic testing. Her posterior pole examination demonstrated retinal pigment epithelium (RPE) mottling with extensive macular drusen and paracentral chorioretinal atrophy, consistent with a fleck retinopathy. Her past medical history was remarkable for nephrectomy for unilateral renal malignancy, parotid tumors and thyroid nodules. Dark adaptation time was prolonged, and electroretinography (ERG) revealed abnormal waveforms with depressed amplitudes. Genetic testing confirmed a deletion mutation in the folliculin ( ) gene and was negative for other relevant mutations, including responsible for autosomal dominant macular and peripapillary drusen in Doyne honeycomb retinal dystrophy and responsible for Sorsby Fundus Dystrophy. BHD is a rare autosomal-dominant disorder with multi-systemic clinical manifestations caused by a mutation in the gene. Affected individuals are prone to renal and pulmonary cysts, renal cancer, and fibrofolliculomas. Reports on ocular manifestations of BHD include eyelid fibrofolliculomas, flecked chorioretinopathy, choroidal melanoma, choroidal melanoma with sector melanocytosis, and retinal pigment epithelial micro-detachments. In this case of BHD, we note a fleck retinopathy with bilateral chorioretinal atrophy, displaying a phenotype of extensive chorioretinopathy associated with impaired dark adaptation and ERG abnormalities. BHD: Birt-Hogg-Dubé syndrome; : Folliculin. RPE: retinal pigment epithelium; OD: (right eye); OS: (left eye). OU: (both eyes); ERG: electroretinogram; mfERG: multifocal electroretinography. ffERG: full-field electroretinography; FAF: fundus autofluorescence; OCT: optical coherence tomography; FA: fluorescein angiography; DA: dark-adapted; LA: light-adapted; mTOR: mammalian target of rapamycin; : epithelial growth factor-containing fibulin-like extracellular matrix protein 1; : Vacuolar Protein Sorting 13 Homolog B; : AATP/GTP-Binding Protein Like 5; : Alstrom Syndrome 1; : Collagen Type I Beta, Alpha Chain 1; : Rod Phosphodiesterase 6-alpha; : Usherin 2a; : Versican; RP: Retinitis pigmentosa; AR: Autosomal recessive.