Long-term follow-up of a patient with JAG1-associated retinopathy

Intraretinal hemorrhages and detailed retinal phenotype of three patients with Alagille syndrome

PURPOSE

To explore patterns of disease expression in Alagille syndrome (ALGS).

METHODS

Patients underwent ophthalmic examination, optical coherence tomography (OCT) imaging, fundus intravenous fluorescein angiography (IVFA), perimetry and full-field electroretinograms (ffERGs). An adult ALGS patient had multimodal imaging and specialized perimetry.

RESULTS

The proband (P1) had a heterozygous pathogenic variant in JAG1; (p.Gln410Ter) and was incidentally diagnosed at age 7 with a superficial retinal hemorrhage, vascular tortuosity, and midperipheral pigmentary changes. The hemorrhage recurred 15 months later. Her monozygotic twin sister (P2) had a retinal hemorrhage at the same location at age 11. Visual acuities for both patients were 20/30 in each eye. IVFA was normal. OCT showed thinning of the outer nuclear in the peripapillary retina. A ffERG showed normal cone-mediated responses in P1 (rod-mediated ERGs not documented), normal ffERGs in P2. Coagulation and liver function were normal. An unrelated 42-year-old woman with a de-novo pathogenic variant (p. Gly386Arg) in JAG1 showed a similar pigmentary retinopathy and hepatic vascular anomalies; rod and cone function was normal across large expanses of structurally normal retina that sharply transitioned to a blind atrophic peripheral retina.

CONCLUSION

Nearly identical recurrent intraretinal hemorrhages in monozygotic twins with ALGS suggest a shared subclinical microvascular abnormality. We hypothesize that the presence of large areas of functionally and structurally intact retina surrounded by severe chorioretinal degeneration, is against a predominant involvement of JAG1 in the function of the neurosensory retina, and that instead, primary abnormalities of chorioretinal vascular development and/or homeostasis may drive the peculiar phenotypes.

THREE-YEAR FOLLOW-UP OF PROGRESSIVE CHORIORETINAL ATROPHY IN ATYPICAL ALAGILLE SYNDROME: A CASE REPORT

PURPOSE

To report a case of atypical Alagille syndrome with progressive chorioretinal atrophy.

METHODS

Case Report.

RESULTS

A 42-year-old Japanese man presented with atypical Alagille syndrome. At the first visit, funduscopy revealed anterior circumferential chorioretinal atrophy in the peripheral retina and peripapillary region with posterior pole sparing in both eyes. Fundus autofluorescence showed hypoautofluorescence in the peripheral and peripapillary regions, but normal findings in the macular region. After follow-up for 3 years, hypopigmented area with well visualized large choroidal vessels extended to mid-peripheral region. On Fundus autofluorescence images, hypoautofluorescence newly appeared in macular region in both eyes. Perivascular hypoautofluorescence and granular hyperautofluorescence scattering within the posterior pole were also observed. BCVA deteriorated and concentric visual field contraction worsened progressively.

CONCLUSION

Alagille syndrome is known to have many ophthalmic manifestations, most of which are stable with minimal threat to vision. In the present case, chorioretinal atrophy progressed during 3-year follow-up, suggesting that progression of chorioretinal atrophy with vision loss may occur over time in Alagille syndrome.

Cellular and Molecular Mechanisms of Pathogenesis Underlying Inherited Retinal Dystrophies

Inherited retinal dystrophies (IRDs) are congenital retinal degenerative diseases that have various inheritance patterns, including dominant, recessive, X-linked, and mitochondrial. These diseases are most often the result of defects in rod and/or cone photoreceptor and retinal pigment epithelium function, development, or both. The genes associated with these diseases, when mutated, produce altered protein products that have downstream effects in pathways critical to vision, including phototransduction, the visual cycle, photoreceptor development, cellular respiration, and retinal homeostasis. The aim of this manuscript is to provide a comprehensive review of the underlying molecular mechanisms of pathogenesis of IRDs by delving into many of the genes associated with IRD development, their protein products, and the pathways interrupted by genetic mutation.

Atypical Focal Choroidal Excavation with Macular Hole in a Patient with Alagille Syndrome

This study is aimed at reporting a rare and unusual focal choroidal excavation with a macular hole in a patient with Alagille syndrome (AGS). A 21-year-old woman with an established early-life AGS diagnosis was referred to our hospital prior to liver transplantation. Examination revealed best-corrected visual acuity of 16/20 and 20/20 in the right and left eye, respectively. Slit-lamp examination was positive for posterior embryotoxon in both eyes. Fundoscopy revealed diffuse choroidal hypopigmentation with increased visibility of the choroidal blood vessels and circumferential chorioretinal atrophy in the mid-peripheral and peripheral retina in both eyes. A full-thickness macular hole with underlying focal choroidal excavation was observed in the right eye. Optical coherence tomography through the macula confirmed choroidal excavation with a full-thickness macular hole in the right eye. To our knowledge, this is the first report describing focal choroidal excavation with a macular hole in an AGS patient.

Macular atrophy in JAG1-related Alagille syndrome: a case series

BACKGROUND

: Alagille syndrome (AS) is a multisystem disorder associated with a range of ocular anomalies affecting the anterior and posterior segments. While chorioretinal abnormalities have been reported in Alagille Syndrome, identification of macular dystrophy and detailed clinical and electrophysiologic descriptions are scarce.

MATERIALS AND METHODS

: A retrospective review was conducted to identify patients with a diagnosis of AS and retinal disease who were evaluated in the Division of Pediatric Ophthalmology, Strabismus, and Adult Motility at UPMC Children's Hospital of Pittsburgh. Criteria of AS included biopsy-proven bile duct hypoplasia, presence of major clinical features of AS, and molecular confirmation of the JAG1 gene.

RESULTS

: This cohort included three patients, two females and one male, diagnosed with JAG1-Alagille syndrome. The diagnosis was made before 2 years of life in all patients. The mean follow-up period in our center was 8 years. All patients were found to have retinal pigmentary changes, macular atrophy, choroidal thinning, optic disc anomalies, and progressive decrease in vision. Marked retinal and macular dysfunction were found in electrophysiological studies.

CONCLUSIONS

: Three patients with molecularly confirmed Alagille syndrome demonstrated unusual retinal and macular findings, with two showing progressive vision loss. Due to the rarity of retinal findings in AS and the observed progression of disease in our patients, clinical genetic testing for retinal dystrophies could be completed in two cases. These investigations failed to reveal a separate molecular cause for the observed retinal dystrophy, helping to confirm the association with JAG1-related AS.