Ophthalmic findings in a family with early-onset isolated ectopia lentis and the p.Arg62Cys mutation of the fibrillin-1 gene (FBN1)

Purpose: The purpose of this paper is to describe ophthalmic findings in a family with isolated ectopia lentis (EL) caused by a specific FBN1 mutation.

Methods: Detailed family histories and clinical data were recorded for six isolated EL patients of 11 family members. The ophthalmological and systematic examinations were performed on patients and unaffected members of the investigated family. The detailed ocular examinations included visual acuity, anterior chamber depth, pupil size, lens location, optometry, central corneal thickness, keratometry, slitlamp examination, fundus examination, axial length, ocular B-ultrasound, gonioscope checking, ultrasound biomicroscopy (UBM) and intraocular pressure (IOP; Goldmann applanation tonometer). Systematic examinations included the measurement of echocardiogram, height, arm span, skull, face, jaw, tooth, breast bone, spinal column, and skin. Genomic DNA was extracted using the phenol-chloroform extraction method for all subjects, and sequencing was carried out on an ABI Prism 3730 Genetic Analyzer.

Results: A heterozygous mutation, c.184C>T (p.Arg62Cys) in exon 2 of FBN1 was identified in all affected members but was not found in any unaffected member of the family. Our study presented detailed clinical manifestations, including some novel ophthalmic findings, such as pupillary abnormality, different types of glaucoma, and progressive hyperopia.

Conclusions: Ophthalmic findings and the p.Arg62Cys mutation of FBN1 gene were reported in a family with early-onset isolated ectopia lentis.     

Novel truncating mutation in CACNA1F in a young male patient diagnosed with optic atrophy

ABSTRACT

Background: Low vision in children can be accompanied by pallor of the optic disc with little or no characteristic morphologic changes of the retina. A variety of diseases can be the underlying cause, including hereditary optic atrophy, Leber’s congenital amaurosis (LCA), achromatopsia, and calcium channel, voltage-dependent, L-type, alpha-1F subunit gene (CACNA1F)-associated retinopathy (most widely known as incomplete congenital stationary night blindness: iCSNB). Differentiation at early age is desirable due to large differences in prognosis, but may be difficult because phenotypes overlap and electrophysiological testing is challenging in young patients. We present the case of a 6-year-old boy with unexplained low vision and pallor of the optic disc who originally had been diagnosed with hereditary optic atrophy in the absence of recordable full-field electroretinography (ERG) due to poor patient cooperation.

Materials and Methods: Standard Sanger sequencing excluded mutations in the OPA1 gene (autosomal-dominant optic atrophy). To identify the underlying genetic cause, whole-exome sequencing was performed on patient’s DNA. Recording of the full-field ERG was successfully performed 6 months later.

Results: We identified a novel truncating mutation in CACNA1F gene (NM_001256789: c.3895C > T in exon 33) which led to the correct diagnosis of CACNA1F-associated retinopathy in the young boy. ERG recordings showed a negative scotopic mixed response with preserved oscillatory potentials and a flicker ERG with reduced amplitude and biphasic waveform, compatible with a CACNA1F-asssociated phenotype.

Conclusions: We show that genetic testing may help to differentiate between optic atrophy, LCA, and CACNA1F-associated retinopathy at a much earlier age, in absence of electrophysiological examination and by widely overlapping phenotypes.     

FBN1基因新突变导致常染色体显性遗传眼病晶状体脱位一家系三例分析

目的 通过对一汉族晶状体脱位家系3名患病成员的原纤维蛋白-1（FBN1）基因突变分析,追踪观察眼睛、心血管及全身临床表现,分析FBN1基因突变与临床表型关系。方法 系列病例研究。收集该家系所有成员的眼与心血管系统等全身临床资料。采用聚合酶链式反应和直接测序法对该家系所有成员进行FBN1基因的突变检测。结果 研究发现3名晶状体脱位患者均携带FBN1基因一个新的错义突变（c.1999T>C;p.Cys 515Arg）,而家系中正常个体无此变异。SIFT和PolyPhen-2生物信息学分析数据高度支持该变异为致病性突变。家系中3名患者均存在不同程度的晶状体脱位,1名年长患者还伴有主动脉瘤样扩张。结论 FBN1基因c.1999T>C的突变可导致常染色体显性遗传眼病晶状体脱位。家系患者的的临床表现存在异质性,年轻患者是否可确诊为马凡综合征还需长期追踪观察。     

Electrophysiological findings in a family with congenital arteriohepatic dysplasia (Alagille syndrome)

Arteriohepatic dysplasia (Alagille syndrome) is a congenital cholestatic disease associated with ocular abnormalities. Three Japanese siblings, a 14-year-old girl, an 11 year-old boy, and a 9-year-old girl with this syndrome were studied. All three patients showed neonatal jaundice, hepatic dysfunction, characteristic facies, and psychomental retardation. The two sisters had cardiac murmurs. Ophthalmological examinations revealed that they had posterior embryotoxon, refractive error, retinochoroidal degener ation, and electrophysiological abnormalities. The two sisters showed retinochoroidal degeneration and unilateral high myopia while the brother showed marked retino choroidal degeneration with extensive pigment clumps. Visual fields showed moderate concentric contraction in the two sisters and marked concentric contraction in the brother. Amplitudes of the single flash electroretinogram were moderately reduced in the sisters, the test was nonrecordable in one eye and extensively reduced in the other eye of the brother. The electrooculogram was borderline in the elder sister and abnormal in the brother and younger sister. Visual evoked cortical potential (VECP) were abnormal in the high myopic eye in each of the two sisters. Ophthalmological findings including electrophysiological examinations may help to confirm the diagnosis of this multisystem familial disorder.     

A novel FBN1 missense mutation (p.C102Y) associated with ectopia lentis syndrome in a Chinese family

AIM:To characterize the disease-causing mutations in a Chinese family with ectopia lentis syndrome (ELS).METHODS:Patients and their family members were given complete physical, ophthalmic, and cardiovascular examinations. Genomic DNA samples were extracted from the peripheral blood of the pedigree members and 100 healthy controls. Mutation screening was performed in the fibrillin-1 (FBN1) gene by bi-directional sequencing of the amplified products. The mutation was analyzed using two bioinformatics methods.RESULTS:A novel heterozygous c.305G>A mutation in exon 3 of FBN1 was detected. As a result of this change, a highly conserved cysteine residue was replaced by a tyrosine residue (p.C102Y). Another mutation was found in the same exon (c.303T>C), which did not change the amino acid sequence. Both mutations were discovered in each affected individual, but not in the unaffected family members, or in 100 ethnically matched controls. A bioinformatics analysis predicted that mutation p.C102Y would affect protein function.CONCLUSION:In the first epidermal growth factor-like module, we identified a novel FBN1 mutation (p.C102Y), which caused ELS in the family. Our study presented a unique phenotype, including some distinct ophthalmic findings, such as hypoplasia of the iris and anisometropia. Our results expanded the mutation spectrum of FBN1 and enriched the overall knowledge of genotype-phenotype correlations due to FBN1 mutations.     

Novel variant in the TP63 gene associated to ankyloblepharon-ectodermal dysplasia-cleft lip/palate (AEC) syndrome

Background: Ankyloblepharon-ectodermal dysplasia-cleft lip/palate (AEC) syndrome is a disorder resulting from anomalous embryonic development of ectodermal tissues. There is evidence that AEC syndrome is caused by mutations in the TP63 gene, which encodes the p63 protein. This is an important regulatory protein involved in epidermal proliferation and differentiation.

Materials and methods: Genome sequencing was performed in DNA from peripheral blood leukocytes of a newborn with AEC syndrome and her parents. Variants were searched in all coding exons and intron-exon boundaries of the TP63 gene.

Results: A heterozygous missense variant (NM_003722.4:c.1063G>C (p.Asp355His) was found in the newborn patient. No variants were found in either of the parents.

Conclusions: We identified a previously unreported variant in TP63 gene which seems to be involved in the somatic malformations found in the AEC syndrome. The absence of this variant in both parents suggests that the variant appeared de novo.     

Correlation of the recurrent FBN1 mutation (c.364C>T) with a unique phenotype in a Chinese patient with Marfan syndrome

Purpose  To describe a Chinese patient with Marfan syndrome who had a unique phenotype and a recurrent mutation in the fibrillin-1 (FBN1) gene. Case and Methods  A 31-year-old man who had a spontaneous bilateral lens dislocation into the vitreous cavity in childhood was found to have retinal and choroidal detachments in both eyes. A congenital atrial septal defect was detected. Pars plana vitrectomy, lensectomy, and silicone oil tamponade were performed on his right eye. Genomic DNA was extracted from leukocytes of peripheral blood, and the 65 exons and flanking intronic sequences of the FBN1 gene were amplified by polymerase chain reaction for mutational screening. Results  A recurrent mutation, c.364C>T was detected in exon 4 that resulted in p.Arg122Cys. The visual acuity of the right eye improved to 6/60 one year after the surgeries. Conclusion  DNA screening helps in the diagnosis of Marfan syndrome with unique phenotypes. The mutation c.364C>T can be considered to be a hotspot for Marfan patients with predominant ectopia lentis.     

A novel missense mutation in BEST1 associated with an autosomal-dominant vitreoretinochoroidopathy (ADVIRC) phenotype

ABSTRACT

Background: To report a 68-year-old female with an autosomal-dominant vitreoretinochoroidopathy (ADVIRC) phenotype associated with a subretinal hemorrhage (SRH) and novel BEST1 pathogenic variation p.Met571Thr.

Materials and Methods: The patient was assessed by fundus photography, fluorescence and indocyanine green angiography, spectral-domain optical coherence tomography, photopic and scotopic electroretinogram (ERG), and electrooculogram (EOG). Whole-exome and Sanger sequencing of the patient’s and selected family members’ DNA was performed. Ophthalmoscopic examinations were also performed on six patient’s relatives.

Results: The patient presented moderate vitreous and SRH in the left eye. A distinct, annular hyperpigmented band was present in both eyes. Vitrectomy improved visual acuity, and the SRH gradually regressed without recurrence. Preserved macular function was shown by optical coherence tomography (OCT). Genetic analysis identified a novel heterozygous mutation, resulting in p.Met571Thr in BEST1. No mutations were observed in a panel of other eye disease genes, suggesting that this pathogenic variation in BEST1 is associated with an ADVIRC phenotype. No other evaluated family member had the variant or the fundus findings.

Conclusions: We present a patient with a novel p.Met571Thr pathogenic variation associated with an ADVIRC phenotype. SRH is a unique finding in ADVIRC patients and may correspond to peripheral exudative hemorrhagic chorioretinopathy. The BEST1 pathogenic variation p.Met571Thr might be the likely cause of ADVIRC in this patient. However, further study is necessary to determine whether this mutation is causative.     

Intraretinal cystoid spaces in a patient with retinitis pigmentosa due to mutation in the MAK gene

Background: Cystoid macular edema (CME) and non-leaking intraretinal cystoid spaces (ICS) have different pathophysiologic mechanisms.

Materials and methods: We report a patient with retinitis pigmentosa (RP) with ICS due to a mutation in the male germ cell-associated kinase (MAK) gene.

Results: A 41-year-old Ashkenazi Jewish male was referred for abnormal visual field revealed by regular optometric examination. His visual acuity was 20/20 in each eye. Dilated examination revealed typical finding of RP. Optical coherence tomography showed cystoid changes in each fovea. Photoreceptors were also degenerated. Intravenous fluorescein angiography showed no leakage. Genetic testing identified a homozygous mutation in the MAK gene: a 353-bp Alu insertion (K429insAlu).

Conclusions: Mak regulates microtubule stability via phosphorylating RP1. Abnormal Mak may impact retinal photoreceptor ciliary length and subcompartmentalization. Mak is required for the survival of photoreceptors in mice. ICS has been reported in other ciliopathies. We report the first case of ICS due to mutation in MAK.     

Clinical characteristics of recessive retinal degeneration due to mutations in the CDHR1 gene and a review of the literature

Background: The clinical phenotype of patients presenting with autosomal recessive CDHR1-related retinopathy has not been well described.

Materials and Methods: This is a retrospective case series of patients presenting to a single institution. Clinical data, including age, visual acuity, dilated fundus exam, fundus photos, fundus autofluorescence (FAF), optical coherence tomography, full-field electroretinograms (ERGs), and results of genetic testing, were collected.

Results: Four patients were identified to have biallelic mutations in the CDHR1 gene. All four patients were found to have at least one c.783G>A (p.Pro261 = ) mutation. A novel splice site mutation, c.152-2A>G, was identified in two patients. Patients became symptomatic between the fourth and sixth decades of life. Three patients presented initially with nyctalopia and peripheral visual field constriction, and one patient presented with simultaneous onset of photophobia and nyctalopia. The fundus appearance was characterized by macular atrophy with or without peripheral retinal pigment epithelium changes and arteriolar attenuation. FAF showed a hyperautofluorescent ring surrounding a central area of speckled hypoautofluorescence. Full-field electroretinography was available on three patients and showed decreased cone-and-rod responses.

Conclusions: CDHR1-related retinal dystrophy should be considered in adult patients with a retinal dystrophy who present with symptoms of cone-and-rod dysfunction and macular atrophy on ophthalmoscopic examination.     

Identification of a novel mutation in the FGF10 gene in a Chinese family with obvious congenital lacrimal duct dysplasia in lacrimo-auriculo-dento-digital syndrome

AIM: To identify the pathogenic gene variant in a family with lacrimo-auriculo-dento-digital syndrome [LADD (MIM 149730)] showing congenital lacrimal duct dysplasia as the main clinical manifestation and lay the foundation for future research on the pathogenic gene.METHODS: Ophthalmological examinations, including slit-lamp biomicroscopy and lacrimal duct probing, and computed tomography dacryocystography (CT-DCG) were performed for all participants. The family pedigree was drawn, genetic features were analyzed, and the genomic DNA of the subjects was extracted. Pathogenic genes were screened via whole exome sequencing (WES) and confirmed using Sanger sequencing.RESULTS: Six patients belonged to this three-generation family, and their clinical manifestations included congenital nasolacrimal duct obstruction, congenital absence of lacrimal puncta and canaliculi, lacrimal fistulae, and limb deformities. This pattern indicates autosomal dominant inheritance. Diagnosis was based on the clinical characteristics of LADD syndrome, which presented in all the patients in this family. A novel frameshift mutation in the FGF10 gene (NM_004465.1), c.234dupC (p.Trp79Leus*15), was identified in all patients via WES. The variant was confirmed by Sanger sequencing and classified as a “pathogenic mutation” according to the American College of Medical Genetics and Genomics (ACMG) variant interpretation guidelines.CONCLUSION: A novel frameshift mutation in the FGF10 gene is found in all patients. This finding helps this family with LADD syndrome receiving a more accurate clinical diagnosis and genetic counseling by extending the mutation range of the FGF10 gene.     

泪腺肿瘤中P53蛋白表达的意义

目的了解P53基因在泪腺肿瘤的表达及其临床病理学意义。方法应用免疫组织化学ABC法检测57例泪腺上皮性肿瘤患者和10例正常人泪腺组织中P53蛋白的表达情况，并与病理分级、复发相联系。结果10例正常人泪腺组织中P53表达全部为阴性；恶性肿瘤患者的表达率为48．6％，良性肿瘤中P53达率为18％，二者相比有显著性差异（P＜0．025）；复发患者阳性率为76．9％，明显高于未复发患为31．8％（P＝0．015）。结论P53基因参与了泪腺肿瘤的发生发展并与肿瘤的分化和复发有关。     

A novel compound heterozygous mutation in the cellular retinaldehyde-binding protein gene (RLBP1) in a patient with retinitis punctata albescens

PURPOSE: To describe a patient with retinitis punctata albescens (RPA) associated with compound heterozygosity for two novel mutations in the RLBP1 encoding cellular retinaldehyde-binding protein (CRALBP). DESIGN: Observational case report. METHODS: The proband underwent a complete ophthalmic examination and leukocyte genomic DNA samples were obtained from him and his parents. The RLBP1 exons were analyzed by direct sequencing of PCR-amplified fragments. RESULTS: The patient had a clinical phenotype suggestive of slowly progressive RPA, characterized by numerous yellow-white dots in the fundus. The RLBP1 sequence analysis revealed a novel compound heterozygotic mutation of Gly145Asp and Ile200Thr transmitted from the mother and father, respectively. Analysis of 100 control chromosomes showed no individuals with these sequence alterations. CONCLUSIONS: Only eight RLBP1 mutations have been reported to date, and here we describe two novel mutations. These additional mutations will aid ongoing functional studies and add to our understanding of the molecular pathology pertaining to RLBP1-associated retinopathies.     

Long-Term Macular Changes in the First Proband of Autosomal Dominant Vitreoretinochoroidopathy (ADVIRC) Due to a Newly Identified Mutation in BEST1

Background: Mutations in BEST1 account for autosomal dominant vitreoretinochoroidopathy (ADVIRC), a rare inherited retinal dystrophy with presenile cataracts and incomplete anterior segment development. The long-term clinical findings and visual prognosis of these patients continues to evolve over time.

Materials and Methods: The retina was assessed by fundus photography, fluorescein angiography, and spectral domain optical coherence tomography. Sanger dideoxy chain-termination sequencing identified mutations in BEST1. Bioinformatic tools were used to predict changes in splicing. An in vitro splicing assay was applied to evaluate for altered pre-mRNA splicing.

Results: Long-term follow up of the first ever reported ADVIRC proband revealed progressive foveal atrophy in both eyes 3 decades after his initial presentation. Progressive retinal ischemia, bilateral iris atrophy, and pseudophakodnesis were observed on follow up. The patient was heterozygous for a c.248G?>?A missense mutation in exon 4 of BEST1, affecting a highly conserved transmembrane domain. Although computational prediction models suggest a change in the binding probability of splicing-associated SR proteins, in vitro splicing assays failed to demonstrate an effect of the c.248G?>?A mutation on splicing of BEST1 exon 3 or exon 4.

Conclusions: Progressive posterior chorioretinal changes occurred over time in the initial ADVIRC proband, leading to visual loss. The causative mutation in this patient falls in the transmembrane domain of the BEST1 protein, with unclear functional consequences. Although previous studies showed alteration in pre-mRNA splicing, in vitro splicing assays failed to demonstrate this in our patient.     

Intraoperative floppy iris syndrome (IFIS): a practical approach to medical and surgical considerations in cataract extractions

Intraoperative floppy iris syndrome (IFIS) during cataract surgery is characterized by iris fluttering, iris prolapse towards the incisions, and a progressive pupillary constriction leading to high rates of complications. The syndrome has been reported following the treatment of benign prostatic hyperplasia with α‐1_a adrenergic receptor inhibitors, especially tamsulosin. The present paper describes the syndrome and discusses its pharmacological background. Several techniques to prevent and to deal with the syndrome are presented.     

A case report of a patient with Pfeiffer syndrome,an FGRF 2 mutation (Trp290Cys) and unique ocular anterior segment findings

Purpose:?To report a case of a child with Pfeiffer syndrome, unique ocular anterior segment findings and a mutation in FGFR2 (Trp290Cys).

Methods:?Case Report.

Results:?We describe a patient with Pfeiffer syndrome with a unique constellation of ocular anterior segment anomalies including microcornea, limbal scleralization, corectopia and glaucoma. Genomic DNA extraction was heterozygous for a G to T mutation at nucleotide 870 of the fibroblast growth factor receptor 2 gene (FGFR2) which changes tryptophan (TGG) to cysteine (TGT) at amino acid position 290 (Trp290Cys).

Conclusion:?This case supports the association between Pfeiffer syndrome and severe ocular anterior segment anomalies, including glaucoma, and underscores the possible role that FGFR2 has in development of the anterior segment of the eye.     

Association of the DNA repair SMUG1 rs3087404 polymorphism and its interaction with high sensitivity C-reactive protein for age-related macular degeneration in Iranian patients

Background: Age-related macular degeneration (AMD) is a complex disease and recently the role of DNA repairing genes in its susceptibility has been studied. It has been hypothesized that polymorphism in DNA repair system genes reduce the capacity to repair DNA damages which may lead to a greater susceptibility to AMD. C-reactive protein (CRP) production is shown to enhance inflammatory processes by increasing oxidative stress and inducing DNA damage. We planned to evaluate the possible association of SMUG1 variants and their possible interaction with high sensitivity CRP levels in AMD.

Materials and methods: We included 500 case-control samples consisting of 279 advanced type AMD patients and 221 genetically unrelated healthy controls enrolled for evaluation. Extracted-DNA samples were amplified to obtain fragments including the polymorphic region SMUG1 rs3087404. We calculated relative excess risk due to interaction (RERI), attributable proportion (AP), and synergy index (S) to clarify possible interaction of different genotypes and CRP levels for AMD.

Results: The distribution of the genotypes were not significantly different in the AMD patients compared to that of controls (p = 0.849). The allele frequency for SMUG1 was not different between study groups. No difference of SMUG1 polymorphism between case and control groups was evident in higher CRP levels (CRP>3mg/dl) compared with lower CRP levels. SMUG1/CRP synergy indices calculated as RERI = ?0.12 and AP = ?0.18 while S was not calculable.

Conclusions: Our study showed that c.-31A/G-SMUG1 genotypes/alleles do not have any association with the occurrence or severity of advanced type AMD. There was no interaction of CRP levels and SMUG1 genotypes in AMD susceptibility.     

A novel mutation in the aspartate beta-hydroxylase (ASPH) gene is associated with a rare form of Traboulsi syndrome

ABSTRACT

Background

Traboulsi syndrome is a rare autosomal recessive genetic disorder. The present study aimed to identify the pathogenic variants in the ASPH gene responsible for a rare and unique presentation of Traboulsi syndrome associated with cardiac disorder.     

Novel compound heterozygous mutations in the cytochrome P4501B1 gene (CYP1B1) in a Japanese patient with primary congenital glaucoma

Leber's hereditary optic neuropathy (LHON) is a maternally inherited disorder characterized by a rapid bilateral loss of central vision. The majority of patients have one of three mutations in the mitochondrial DNA. In order to identify the genetic cause of the disease in a family with two affected individuals without any of the three primary LHON mutations, we have sequenced the complete mitochondrial genome. Sequence analysis revealed a point mutation at position 14568 in the mitochondrial ND6 gene that changes a conserved methionine residue to isoleucine. This mutation has been previously suggested to be of pathogenic significance and has not been detected in any controls. This case confirms the pathogenicity of this mutation. It is the seventh mutation in the ND6 gene leading to LHON. All seven identified mutations in the ND6 gene lie within the evolutionarily most conserved region of the ND6 gene in a hydrophobic pocket making it a hot spot for the disease. This clustering of mutations may help to understand the disease mechanism of LHON.