Dataset Information

MFRP-Associated Retinopathy and Nanophthalmos in Two Irish Probands: A Case Report.

ABSTRACT: The conjunction of nanophthalmos (NO) and retinitis pigmentosa (RP) provides challenges to effective clinical management while narrowing the genetic spectrum for targeted molecular diagnostics. This case study describes two not knowingly related adult cases of MFRP-associated retinopathy and nanophthalmos (MARN). Structural features including short axial lengths (mean 16.4 mm), steep keratometry (mean 49.98 D), adult-onset signs, and symptoms of retinal dystrophy and acquired disease (i.e., cataract, angle-closure glaucoma) were evident in both cases. Pathogenic variants in the MFRP gene impair both prenatal eye growth and childhood emmetropization while also leading to RPE/outer retinal degeneration in 75% of cases. We discuss the "small-eye" phenotype spectrum and associated defining characteristics, molecular mechanisms with particular focus on MFRP-associated NO with RP features (MARN), the spectrum of visual morbidities (e.g., extreme refractive error, amblyopia, cystoid macular lesions, early cataract) and the challenges of their treatment/surgical management.

SUBMITTER: O'Connell A

PROVIDER: S-EPMC9808125 | biostudies-literature | 2022 Sep-Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

<i>MFRP</i>-Associated Retinopathy and Nanophthalmos in Two Irish Probands: A Case Report.

O'Connell Ann A Zhu Julia J Stephenson Kirk A J KAJ Whelan Laura L Dockery Adrian A Turner Jacqueline J O'Byrne James J JJ Farrar G Jane GJ Keegan David D

Case reports in ophthalmology 20220901 3

The conjunction of nanophthalmos (NO) and retinitis pigmentosa (RP) provides challenges to effective clinical management while narrowing the genetic spectrum for targeted molecular diagnostics. This case study describes two not knowingly related adult cases of <i>MFRP</i>-associated retinopathy and nanophthalmos (MARN). Structural features including short axial lengths (mean 16.4 mm), steep keratometry (mean 49.98 D), adult-onset signs, and symptoms of retinal dystrophy and acquired disease (i.e ...[more]

PMID: 36605040

Similar Datasets

Project description:BackgroundNanophthalmos has a significant genetic background and disease-causing mutations have been recently been reported in the myelin regulatory factor (MYRF) gene. We report clinical features in a patient with nanophthalmos and a Thr518Met MYRF mutation.Case presentationA three-year-old male was discovered to have nanophthalmos after first presenting to the emergency department for a frontal headache, eye pain, emesis, and lethargy. Imaging studies (CT and MRI) were negative except for increased posterior fossa cerebrospinal fluid. Subsequent examinations revealed nanophthalmos (short axial eye lengths 18.1 mm OD and 18.3 mm OS), microcornea, and a large crystalline lens. Peripheral chorioretinal pigment abnormalities were also observed. He experienced episodes of marked ocular hypertension (53 mmHg OD and 60 mmHg) likely due to intermittent angle closure precipitated by nanophthalmos. The ocular hypertension was responsive to topical medicines. Genetic analysis of known nanophthalmos genes MFRP and TMEM98 were negative, while a novel mutation, Thr518Met was detected in MYRF. The Thr518Met mutation was absent from 362 matched normal controls and was extremely rare in a large population database, allele frequency of 0.000024. The Thr518Met mutation altered a highly conserved amino acid in the MYRF protein and three of four algorithms suggested that this mutation is likely pathogenic. Finally, molecular modeling showed that the Thr518Met mutation is damaging to MYRF structure. Together these data suggest that the Thr518Met mutation causes nanophthalmos.ConclusionsNanophthalmos may present at an early age with features of angle closure glaucoma and a Thr518Met mutation in MYRF was detected in a patient with nanophthalmos. Prevalence data, homology data, mutation analysis data, and protein modeling data suggest that this variant is pathogenic and may expand the phenotypic range of syndromic nanophthalmos caused by MYRF mutations to include central nervous system abnormalities (increased posterior fossa cerebrospinal fluid).

Project description:PurposeTo report a new familial case of the recently described autosomal recessive syndrome of nanophthalmos-retinitis pigmentosa-foveoschisis-optic disc drusen, which arises from compound heterozygosity for Membrane Frizzled-Related Protein (MFRP) mutations in a sibling pair of Mexican origin.MethodsOphthalmological assessment included slit-lamp and dilated fundus examination, applanation tonometry, fundus photography, A-mode and B-mode ultrasound examination, electroretinogram, fluorescein retinal angiography, optical coherence tomography, and electrooculogram in both affected siblings. Molecular genetic analysis consisted of PCR amplification and direct automated sequence of the complete coding region of the MFRP gene. In addition, allele-specific cloning and sequencing techniques were used to characterize a heterozygous MFRP frameshift mutation.ResultsClinical examination revealed high hyperopia of > +16 diopters while electroretinographic and fluorangiographic studies demonstrated a retinal dystrophy compatible with retinitis pigmentosa. Ultrasound examination showed nanophthalmos (eye axial length <15 mm) and optic disc drusen while optical coherence tomography evidenced cystoid macular edema. Nucleotide sequencing in DNA from both affected siblings disclosed the presence of two MFRP mutations: a novel heterozygous point mutation predicting a nonsense change from tyrosine (TAC) to a stop signal (TAA) at codon 317, and a heterozygous 1 bp deletion in exon 5, predicting a prematurely truncated protein (p.Asn167ThrfsX25).DiscussionThe third known family with the syndrome of nanophthalmos-retinitis pigmentosa-foveoschisis-optic disc drusen is presented. This is the first demonstration of compound heterozygosity for MFRP mutations as the source of the disease. The affected siblings described here are the youngest patients with the disease reported to date and the comparison of their clinical data with previous individuals with this syndrome suggest that some aspects of the phenotype are probably age-dependent.

Dataset Information

MFRP-Associated Retinopathy and Nanophthalmos in Two Irish Probands: A Case Report.

Publications

<i>MFRP</i>-Associated Retinopathy and Nanophthalmos in Two Irish Probands: A Case Report.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets