Leber Hereditary Optic Neuropathy in a Family of Carriers of MT-ND5 m.13042G>T (A236S) Novel Variant.

BACKGROUND: A Slovenian three-generation family with 3 individuals with bilateral optic neuropathy and 2 unaffected relatives with a novel homoplasmic missense variant m.13042G > T (A236S) in the ND5 gene is described. A detailed phenotype at initial diagnosis and a follow-up of bilateral optic neuropathy progression is presented for 2 affected individuals. METHODS: A detailed phenotype analysis with clinical examination in the early and chronic phase with electrophysiology and OCT segmentation is presented. Genotype analysis with full mitochondrial genome sequencing was performed. RESULTS: Two affected male individuals (maternal cousins) had a profound visual loss at an early age (11 and 20 years) with no recovery. The maternal grandmother exhibited bilateral optic atrophy with a history of visual loss at the age 58 years. The visual loss of both affected male individuals was characterized by centrocecal scotoma, abnormal color vision, abnormal PERG N95, and VEP. Later with disease progression, retinal nerve fiber layer thinning was observed on OCT. We observed no other extraocular clinical features. Mitochondrial sequencing identified a homoplasmic novel variant m.13042G > T (A236S) in the MT-ND5 gene, belonging to a haplogroup K1a. CONCLUSIONS: Novel homoplasmic variant m.13042G > T (A236S) in the ND5 gene in our family was associated with Leber hereditary optic neuropathy-like phenotype. However, predicting the pathogenicity of a novel ultra-rare missense variant in the mitochondrial ND5 gene is challenging. Genetic counseling should consider genotypic and phenotypic heterogeneity, incomplete penetrance, haplogroup type, and tissue-specific thresholds.

Correlation between the Serum Concentration of Vitamin A and Disease Severity in Patients Carrying p.G90D in RHO, the Most Frequent Gene Associated with Dominant Retinitis Pigmentosa: Implications for Therapy with Vitamin A.

The pathogenic variant p.G90D in RHO is believed to be responsible for a spectrum of phenotypes, including congenital stationary blindness (for the purpose of this study termed night blindness without degeneration; NBWD), Sector RP, Pericentral RP, and Classic RP. We present a correlation between the serum concentration of vitamin A and disease severity in patients with this variant. This prospective study involved 30 patients from 7 families (17 male; median age 46 years, range 8−73). Full ophthalmological examination including visual acuity, Goldmann perimetry, slit-lamp exam, optical coherence tomography, fundus autofluorescence, and electrophysiology was performed to determine the presenting phenotype. The serum concentration of vitamin A was determined from a fasting blood sample taken on the day of the exam, where it was found that 23.3% (7/30) of patients had NBWD, 13.3% (4/30) had Sector RP, 3.3% (1/30) had Pericentral RP, and 60% (18/30) had Classic RP. Multiple logistic regression revealed a significantly higher probability of having a milder phenotype (NBWD or Sector RP) in association with younger age (p < 0.05) and a higher concentration of vitamin A (p < 0.05). We hypothesize that vitamin A in its 11-cis-retinal form plays a role in stabilizing the constitutively active p.G90D rhodopsin and its supplementation could be a potential treatment strategy for p.G90D RHO patients.

Genetic Characteristics and Long-Term Follow-Up of Slovenian Patients with RPGR Retinal Dystrophy.

Genetic characteristics and a long-term clinical follow-up of 18 Slovenian retinitis pigmentosa GTPase regulator (RPGR) patients from 10 families with retinitis pigmentosa (RP) or cone/cone-rod dystrophy (COD/CORD) are reported. RP (eight families) was associated with two already known (p.(Ser407Ilefs*46) and p.(Glu746Argfs*23)) and five novel variants (c.1245+704_1415-2286del, p.(Glu660*), p.(Ala153Thr), c.1506+1G>T, and p.(Arg780Serfs*54)). COD (two families) was associated with p.(Ter1153Lysext*38). The median age of onset in males with RP (N = 9) was 6 years. At the first examination (median age of 32 years), the median best corrected visual acuity (BCVA) was 0.30 logMAR, and all patients had a hyperautofluorescent ring on fundus autofluorescence (FAF) encircling preserved photoreceptors. At the last follow-up (median age of 39 years), the median BCVA was 0.48 logMAR, and FAF showed ring constriction transitioning to patch in 2/9. Among females (N = 6; median age of 40 years), two had normal/near-normal FAF, one had unilateral RP (male pattern), and three had a radial and/or focal pattern of retinal degeneration. After a median of 4 years (4-21) of follow-up, 2/6 exhibited disease progression. The median age of onset in males with COD was 25 years. At first examination (median age of 35 years), the median BCVA was 1.00 logMAR, and all patients had a hyperautofluorescent FAF ring encircling foveal photoreceptor loss. At the last follow-up (median age of 42 years), the median BCVA was 1.30 logMAR, and FAF showed ring enlargement. The majority of the identified variants (75%; 6/8) had not been previously reported in other RPGR cohorts, which suggested the presence of distinct RPGR alleles in the Slovenian population.

The Clinical Spectrum and Disease Course of DRAM2 Retinopathy.

Pathogenic variants in DNA-damage regulated autophagy modulator 2 gene (DRAM2) cause a rare autosomal recessive retinal dystrophy and its disease course is not well understood. We present two Slovenian patients harboring a novel DRAM2 variant and a detailed review of all 23 other patients described to date. Whole exome and whole genome sequencing were performed in the two patients, and both underwent ophthalmological examination with a 2-year follow-up. PubMed was searched for papers with clinical descriptions of DRAM2 retinopathy. Patient 1 was homozygous for a novel variant, p.Met1?, and presented with the acute onset of photopsia and retina-wide retinopathy at the age of 35 years. The patient was first thought to have an autoimmune retinopathy and was treated with mycophenolate mofetil, which provided some symptomatic relief. Patient 2 was compound heterozygous for p.Met1? and p.Leu246Pro and presented with late-onset maculopathy at the age of 59 years. On review, patients with DRAM2 retinopathy usually present in the third decade with central visual loss, outer retinal layer loss on optical coherence tomography and a hyperautofluorescent ring on fundus autofluorescence. Either cone-rod or rod-cone dystrophy phenotype is observed on electroretinography, reflecting the importance of DRAM2 in both photoreceptor types. Non-null variants can result in milder disease.

Disease Progression in CNGA3 and CNGB3 Retinopathy; Characteristics of Slovenian Cohort and Proposed OCT Staging Based on Pooled Data from 126 Patients from 7 Studies.

Achromatopsia has been proposed to be a morphologically predominately stable retinopathy with rare reports of progression of structural changes in the macula. A five-grade system of optical coherence tomography (OCT) features has been used for the classification of structural macular changes. However, their association with age remains questionable. We characterized the Slovenian cohort of 12 patients with pathogenic variants in CNGA3 or CNGB3 who had been followed up with OCT for up to 9 years. Based on observed structural changes in association with age, the following four-stage classification of retinal morphological changes was proposed: (I) preserved inner segment ellipsoid band (Ise), (II) disrupted ISe, (III) ISe loss and (IV) ISe and RPE loss. Data from six previously published studies reporting OCT morphology in CNGA3 and CNGB3 patients were additionally collected, forming the largest CNGA3/CNGB3 cohort to date, comprising 126 patients aged 1-71 years. Multiple regression analysis showed a significant correlation of OCT stage with age (p < 0.001) and no correlation with gene (p > 0.05). The median ages of patients with stages I-IV were 12 years, 23 years, 27 years and 48 years, respectively, and no patient older than 50 years had continuous ISe. Our findings suggest that achromatopsia presents with slowly but steadily progressive structural changes of the macular outer retinal layers. However, whether morphological changes in time follow the proposed four-stage linear pattern needs to be confirmed in a long-term study.

Stationary and Progressive Phenotypes Caused by the p.G90D Mutation in Rhodopsin Gene.

Mutations in rhodopsin gene (RHO) are a frequent cause of retinitis pigmentosa (RP) and less often, congenital stationary night blindness (CSNB). Mutation p.G90D has previously been associated with CSNB based on the examination of one family. This study screened 60 patients. Out of these 60 patients, 32 were affected and a full characterization was conducted in 15 patients. We described the clinical characteristics of these 15 patients (12 male, median age 42 years, range 8-71) from three families including visual field (Campus Goldmann), fundus autofluorescence (FAF), optical coherence tomography (OCT) and electrophysiology. Phenotypes were classified into four categories: CSNB (N = 3, 20%) sector RP (N = 3, 20%), pericentral RP (N = 1, 6.7%) and classic RP (N = 8, 53.3% (8/15)). The phenotypes were not associated with family, sex or age (Kruskal-Wallis, p > 0.05), however, cystoid macular edema (CME) was observed only in one family. Among the subjects reporting nyctalopia, 69% (22/32) were male. The clinical characteristics of the largest p.G90D cohort so far showed a large frequency of progressive retinal degeneration with 53.3% developing RP, contrary to the previous report.

Clinical and Histopathological Features of Gelsolin Amyloidosis Associated with a Novel GSN Variant p.Glu580Lys.

Gelsolin amyloidosis typically presents with corneal lattice dystrophy and is most frequently associated with pathogenic GSN variant p.Asp214Asn. Here we report clinical and histopathological features of gelsolin amyloidosis associated with a novel GSN variant p.Glu580Lys. We studied DNA samples of seven members of a two-generation family. Exome sequencing was performed in the proband, and targeted Sanger sequencing in the others. The heterozygous GSN variant p.Glu580Lys was identified in six patients. The patients exhibited corneal dystrophy (5/6), loose skin (5/6) and/or heart arrhythmia (3/6) and one presented with bilateral optic neuropathy. The impact of the mutation on the protein structure was evaluated in silico. The substitution is located in the fifth domain of gelsolin protein, homologous to the second domain harboring the most common pathogenic variant p.Asp214Asn. Structural investigation revealed that the mutation might affect protein folding. Histopathological analysis showed amyloid deposits in the skin. The p.Glu580Lys is associated with corneal dystrophy, strengthening the association of the fifth domain of gelsolin protein with the typical amyloidosis phenotype. Furthermore, optic neuropathy may be related to the disease and is essential to identify before discussing corneal transplantation.

Phenotype-driven gene target definition in clinical genome-wide sequencing data interpretation.

PURPOSE: Genome-wide sequencing approaches are increasingly being used in place of disease gene panel sequencing approaches. Despite the well-recognized benefits of these approaches, they also carry with them an increased burden of analyzing overwhelmingly large gene targets and an increased possibility of detecting incidental findings. METHODS: We propose a novel approach for design of individualized phenotype gene panels using the set of signs and symptoms observed and selecting relevant genes on the basis of known phenotype-gene associations. RESULTS: We used results of diagnostic exome sequencing in 405 cases submitted to our institution to show retrospectively that using the phenotype gene panel increases the sensitivity of masked exome analysis (increase from 25.4 to 29.7% in overall diagnostic yield). We also show that such a strategy enables the possibility of masked analysis of genome-wide sequencing data in patients with poorly defined and multifaceted clinical presentations. Ultimately, we show that this approach enables control over the incidental findings rate (0.25% in phenotype gene panels). Finally, we provide a Web tool for customized phenotype panel creation (available at http://www.kimg.eu/generator). CONCLUSION: In conclusion, we present a novel approach to a phenotype-driven diagnostic process of genome scale sequencing data that harnesses the sensitivity of these approaches while restricting the analysis to genes relevant to clinical presentation in patient.Genet Med 18 11, 1102-1110.

Clinical utility of array comparative genomic hybridisation in prenatal setting.

BACKGROUND: The objective of reported study was to evaluate the clinical utility of prenatal microarray testing for submicroscopic genomic imbalances in routine prenatal settings and to stratify the findings according to the type of fetal ultrasound anomaly. METHODS: From July 2012 to October 2015 chromosomal microarray testing was performed in 218 fetuses with varying indications for invasive prenatal diagnosis: abnormal karyotype, ultrasound anomalies, pathogenic variant in previous pregnancy or carriership in a parent. RESULTS: The detection rate in the group of fetuses with ultrasound anomalies was 10,0% for pathogenic copy number variants (CNVs), five of them being larger than 8 Mb and expected to be seen on prenatal karyotype. If only those pathogenic CNVs below the classical karyotype resolution are considered, chromosomal microarray testing provided an additional 7,7% diagnostic yield in here reported series. When stratified according to the ultrasound anomalies, the highest percentage of pathogenic CNVs were detected in the group of fetuses with multiple congenital anomalies (16,7%) and lowest in the group of isolated in utero growth restriction (6,3%). In the group of cases with isolated increased nuchal translucency we identified a small interstitial deletion of 16p24.1 involving FOXF1 gene. Prenatal aCGH also provided important insights into cases with seemingly balanced chromosomal rearrangements found on prenatal karyotype, where additional pathogenic CNV were discovered. CONCLUSION: Prenatal chromosomal microarray testing significantly increases the diagnostic yield when compared with conventional karyotyping. The highest added value is shown in prenatal diagnostics in fetuses with abnormal ultrasound results. Variants of unknown significance and risk factor CNVs present important challenges and should be discussed with parents in advance, therefore pretest counseling prior to prenatal testing is very important.

Insertion/deletion polymorphism in intron 16 of ACE gene in idiopathic recurrent spontaneous abortion: case-control study, systematic review and meta-analysis.

The insertion/deletion (I/D) polymorphism in intron 16 of the angiotensin I-converting enzyme gene (ACE) has been extensively studied as a predisposing factor for idiopathic recurrent spontaneous abortion (IRSA). A case-control study including 149 women with ≥3 spontaneous abortions and 149 controls was performed to test the association of ACE I/D polymorphism with IRSA. A systematic review was conducted of previous case-control studies, with strict selection criteria for meta-analyses. We also aimed to evaluate the potential differences in summary estimates between studies defining IRSA as ≥2 and ≥3 spontaneous abortions. Genotyping was performed by PCR, and systematic review conducted using PubMed and Scopus. There was no association of the polymorphism with IRSA in Slovenian women. Sixteen case-control studies, showing substantial differences regarding IRSA definition and selection criteria for women were identified. Meta-analysis was performed and included four studies defining IRSA as ≥2 spontaneous abortions and the current study, which defined IRSA as ≥3 spontaneous abortions. Based on random effects model, meta-analysis conducted on 1192 patients and 736 controls showed no association with IRSA under dominant(DD+IDvsII) and recessive(DDvsID+II) genetic models. Well-designed studies are needed to evaluate the role of ACE I/D polymorphism in IRSA defined as ≥3 spontaneous abortions.

Cornelia de Lange syndrome caused by heterozygous deletions of chromosome 8q24: comments on the article by Pereza et al. [2012].

In the March issue of the Journal in 2012, we reported on a girl with Langer-Giedion syndrome (LGS) phenotype and a 7.5 Mb interstitial deletion at 8q23.3q24.13, encompassing the EXT1, but not the TRPS1 gene. Recent discoveries have shown that heterozygous intragenic mutations or contiguous gene deletions including the RAD21 gene, which is located downstream of the TRPS1 gene, are the cause of Cornelia de Lange syndrome-4. Considering that the interstitial deletion in our patient included the RAD21 and 30 other RefSeq genes, we would like to suggest a revision of the diagnosis reported in our previous paper and compare our patient to other reported patients with Cornelia de Lange syndrome-4 caused by heterozygous deletions of chromosome 8q24. © 2015 Wiley Periodicals, Inc.

Stargardt-like Clinical Characteristics and Disease Course Associated with Variants in the WDR19 Gene.

Variants in WDR19 (IFT144) have been implicated as another possible cause of Stargardt disease. The purpose of this study was to compare longitudinal multimodal imaging of a WDR19-Stargardt patient, harboring p.(Ser485Ile) and a novel c.(3183+1_3184-1)_(3261+1_3262-1)del variant, with 43 ABCA4-Stargardt patients. Age at onset, visual acuity, Ishihara color vision, color fundus, fundus autofluorescence (FAF), spectral-domain optical coherence tomography (OCT) images, microperimetry and electroretinography (ERG) were evaluated. First symptom of WDR19 patient was nyctalopia at the age of 5 years. After the age of 18 years, OCT showed hyper-reflectivity at the level of the external limiting membrane/outer nuclear layer. There was abnormal cone and rod photoreceptor function on ERG. Widespread fundus flecks appeared, followed by perifoveal photoreceptor atrophy. Fovea and peripapillary retina remained preserved until the latest exam at 25 years of age. ABCA4 patients had median age of onset at 16 (range 5-60) years and mostly displayed typical Stargardt triad. A total of 19% had foveal sparing. In comparison to ABCA4 patients, the WDR19 patient had a relatively large foveal preservation and severe rod photoreceptor impairment; however, it was still within the ABCA4 disease spectrum. Addition of WDR19 in the group of genes producing phenocopies of Stargardt disease underlines the importance of genetic testing and may help to understand its pathogenesis.

Third case of 8q23.3-q24.13 deletion in a patient with Langer-Giedion syndrome phenotype without TRPS1 gene deletion.

Langer-Giedion syndrome (LGS) is a contiguous gene syndrome caused by a hemizygous deletion on chromosome 8q23.3-q24.11 involving TRPS1 and EXT1 genes. We report on a girl with LGS phenotype and a 7.5 Mb interstitial deletion at chromosome 8q23.3-q24.13. Array-comparative genomic hybridization (a-CGH) revealed a deletion encompassing only the EXT1 and not the TRPS1 gene. Even though the deletion of TRPS1 and EXT1 genes is responsible for craniofacial and skeletal features of LGS, there have been previous reports of patients with LGS phenotype and 8q24 deletions leaving the TRPS1 gene intact. To our knowledge, this is the third such case. Our patient differs from previously reported LGS patients without TRPS1 gene deletion in that she has the typical LGS facial dysmorphism and skeletal abnormalities. However, the girl is of normal height and has only a mild developmental delay. Additionally, she has dyslalia and premature adrenarche classified as Tanner stage 3 premature pubarche which have not yet been described as features of LGS. We examine the molecular breakpoints and phenotypes of our patient and previously reported cases.

Matrix metalloproteinases 1, 2, 3 and 9 functional single-nucleotide polymorphisms in idiopathic recurrent spontaneous abortion.

Idiopathic recurrent spontaneous abortion (IRSA) has been associated with abnormalities in the remodelling of endometrial extracellular matrix, as well as aberrant matrix metalloproteinase (MMP) gene expression in endometrium of IRSA women and chorionic villi of IRSA concept. This study investigated the association of five functional MMP gene promoter polymorphisms (MMP1 -1607 1G/2G, MMP2 -735 C/T, MMP2 -1306 C/T, MMP3 -1612 5A/6A and MMP9 -1562 C/T) with IRSA. A total of 149 couples with at least three consecutive IRSA and 149 fertile couples were included in a case-control study. Genotype analysis was performed using PCR restriction fragment length polymorphism. Statistically significant differences were found in distributions of MMP2 -735 CT (chi-squared 10.21, P=0.006; OR 2.15, 95% CI 1.34-3.45, P=0.001), and MMP9 -1562 CC (chi-squared 9.06, P=0.010; OR 2.21, 95% CI 1.30-3.80, P=0.004) between IRSA women and controls. Combined analysis of MMP gene polymorphisms did not increase their predictive value. There were no statistically significant differences in genotype and allele frequencies of any polymorphism between IRSA men and controls. MMP2 -735 C/T and MMP9 -1562 C/T functional gene polymorphisms might be associated with an increased risk of IRSA in women. Considering the insufficient knowledge on genetic contribution to pregnancy loss, studies on genetic causes of idiopathic recurrent spontaneous abortion (IRSA) are of great importance. Development of a histologically and functionally normal endometrium is critical for subsequent endometrial decidualization, receptivity and implantation. The proper communication and interaction between maternal decidual cells and the embryo is essential for the establishment of a functional fetal-maternal interface. IRSA has been associated with abnormalities in the remodelling of endometrial extracellular matrix, as well as aberrant matrix metalloproteinase (MMP) gene expression in endometrium of IRSA women and chorionic villi of IRSA concepti. The aim of this study was to investigate the association of five functional MMP gene promoter polymorphisms with IRSA. A total of 149 couples with at least three consecutive IRSA and 149 fertile couples were included in a case-control study. Genotype analysis was performed using polymerase chain reaction and restriction fragment length polymorphism. Statistically significant differences were found in distribution of MMP2 -735 CT and MMP9 -1562 CC genotypes between IRSA and control women. Combined analysis of MMP gene polymorphisms did not increase their predictive value. There were no statistically significant differences in distribution of genotype and allele frequencies of any polymorphism between IRSA men and controls. Our results demonstrate that MMP2 -735 C/T and MMP9 -1562 C/T functional gene polymorphisms might be associated with an increased risk of IRSA in women.

The Relative Preservation of the Central Retinal Layers in Leber Hereditary Optic Neuropathy.

(1) Background: The purpose of this study was to evaluate the thickness of retinal layers in Leber hereditary optic neuropathy (LHON) in the atrophic stage compared with presumably inherited bilateral optic neuropathy of unknown cause with the aim of seeing if any LHON-specific patterns exist. (2) Methods: 14 patients (24 eyes) with genetically confirmed LHON (LHON group) were compared with 13 patients (23 eyes) with negative genetic testing results (mtDNA + WES) and without identified etiology of bilateral optic atrophy (nonLHON group). Segmentation analysis of retinal layers in the macula and peripapillary RNFL (pRNFL) measurements was performed using Heidelberg Engineering Spectralis SD-OCT. (3) Results: In the LHON group, the thickness of ganglion cell complex (GCC) (retinal nerve fiber layer (RNFL)­ganglion cell layer (GCL)­inner plexiform layer (IPL)) in the central ETDRS (Early Treatment Diabetic Retinopathy Study) circle was significantly higher than in the nonLHON group (p < 0.001). In all other ETDRS fields, GCC was thinner in the LHON group. The peripapillary RNFL (pRNFL) was significantly thinner in the LHON group in the temporal superior region (p = 0.001). Longitudinal analysis of our cohort during the follow-up time showed a tendency of thickening of the RNFL, GCL, and IPL in the LHON group in the central circle, as well as a small recovery of the pRNFL in the temporal region, which corresponds to the observed central macular thickening. (4) Conclusions: In LHON, the retinal ganglion cell complex thickness (RNFL-GCL-IPL) appears to be relatively preserved in the central ETDRS circle compared to nonLHON optic neuropathies in the chronic phase. Our findings may represent novel biomarkers as well as a structural basis for possible recovery in some patients with LHON.

Case report: Long-term follow-up of two patients with LHON caused by DNAJC30:c.152G>A pathogenic variant-case series.

Background: We present the disease course and long-term follow-up of two patients who were phenotypically diagnosed with atypical Leber Hereditary Optic Neuropathy (LHON) 14 and 12 years ago, respectively, whereby whole exome sequencing revealed recently described recessive DNAJC30:c.152G>A 152 A>G (p.Tyr51Cys) homozygous pathogenic variant with significant spontaneous visual acuity recovery in one. Case presentation: Two presented unrelated males with atypical LHON with sequential visual acuity (VA) loss were followed for many years. Both patients had negative family history. At the presentation at ages 17 (Case 1) and 18 years (Case 2), both had reduced visual acuity (Snellen): (Case 1) right eye (RE):CF 3m, left eye (LE):0.6, (Case 2) RE:0.2, LE:0.15; and color vision (Ishihara): (Case 1) 1/15 and 13/15; (Case 2) 2/15 and 3/15. Both had hyperemic optic disks (PNO) and central scotoma in their visual fields. Electrophysiology in the acute phase showed reduced and delayed visually evoked potentials (VEP) P100 in both patients, with reduced N95 amplitude in Case 2, and initially normal N95 amplitude in Case 1. Fluorescein angiography showed no early leakage with some late pooling at optic disks. Extensive clinical workout, including brain magnetic resonance imaging (MRI), aquaporin 4 (Aq4), and anti-myelin oligodendrocyte protein (anti-MOG) antibodies, was negative. Intravenous corticosteroids did not improve vision. Both experienced further deterioration several months after the onset accompanied by thinning of the peripapillary retinal nerve fiber layer (RNFL). Genetic testing for typical LHON pathogenic variants and whole mitochondrial DNA (mtDNA) sequencing was negative. 1 year after the onset, modest VA improvement began in Case 2 and continued over the next 3 years. VA improved bilaterally to 0.7, color vision 15/15, and islands of vision appeared within the visual field scotoma. VEP P100 peak time shortened, and amplitude increased, despite further RNFL thinning on optical coherent tomography (OCT). The patient's visual function remained stable during the entire 12-year follow-up period. Case 1 experienced modest VA improvement to 0.1 with some improvement in the visual field seven years after the disease onset, remaining stable during the entire 14-year follow-up period. VEP P100 wave remained undetectable. Conclusions: Presented are two autosomal recessive LHON (arLHON, OMIM:619382) cases with the same DNAJC30:c.152G>A pathogenic variant and different degrees of spontaneous visual recovery despite progressive RNFL thinning during a long-term follow-up. This mutation should be screened in every atypical LHON patient.

Association between male infertility and genetic variability at the PON1/2 and GSTM1/T1 gene loci.

Environmental xenobiotics such as organophosphate pesticides are known factors involved in male infertility. Paraoxanase (PON) and glutathione transferase (GST) are involved in biotransformation of organophosphate pesticides. Interindividual genetic variations in biotransformation enzyme activities can lead to differences in the susceptibility to male infertility. This case-control study investigated associations between polymorphisms in the PON and GST genes (PON1-55/192, PON2-311, GSTM1/T1) and infertility. The study group consisted of 187 infertile men (86 with non-obstructive azoospermia (NOA) and 101 with oligoasthenoteratozoospermia (OAT)), whereas the control group comprised of 194 fertile men. Statistically significant differences were found in PON1-55MM genotype (chi-squared=7.37; P=0.02) and PON1-55M allele (chi-squared=5.98; P=0.01) distribution between the infertile and fertile men. A separate analysis revealed that significant differences in genotype frequencies were limited to the OAT group (chi-squared=9.11, P=0.01). However, no significant differences in genotype frequencies of other tested polymorphisms (PON1-192, PON2-311, GSTM1/T1) and male infertility were observed. The PON1-55M allele might represent a risk factor for infertility susceptibility in Slovenian men. Further studies with a larger sample size are needed to confirm these findings.

Cone Dystrophy Associated with a Novel Variant in the Terminal Codon of the RPGR-ORF15.

Mutations in RPGRORF15 are associated with rod-cone or cone/cone-rod dystrophy, the latter associated with mutations at the distal end. We describe the phenotype associated with a novel variant in the terminal codon of the RPGRORF15 c.3457T>A (Ter1153Lysext*38), which results in a C-terminal extension. Three male patients from two families were recruited, aged 31, 35, and 38 years. Genetic testing was performed by whole exome sequencing. Filtered variants were analysed according to the population frequency, ClinVar database, the variant's putative impact, and predicted pathogenicity; and were classified according to the ACMG guidelines. Examination included visual acuity (Snellen), colour vision (Ishihara), visual field, fundus autofluorescence (FAF), optical coherence tomography (OCT), and electrophysiology. All patients were myopic, and had central scotoma and reduced colour vision. Visual acuities on better eyes were counting fingers, 0.3 and 0.05. Electrophysiology showed severely reduced cone-specific responses and macular dysfunction, while the rod-specific response was normal. FAF showed hyperautofluorescent ring centred at the fovea encompassing an area of photoreceptor loss approximately two optic discs in diameter (3462-6342 µm). Follow up after 2-11 years showed enlargement of the diameter (avg. 100 µm/year). The novel c.3457T>A (Ter1153Lysext*38) mutation in the terminal RPGRORF15 codon is associated with cone dystrophy, which corresponds to the previously described phenotypes associated with mutations in the distal end of the RPGRORF15. Minimal progression during follow-up years suggests a relatively stable disease after the initial loss of the central cones.

Diagnostic efficacy and new variants in isolated and complex autism spectrum disorder using molecular karyotyping.

Autism spectrum disorder (ASD) is a group of the neurodevelopment disorders presenting as an isolated ASD or more complex forms, where a broader clinical phenotype comprised of developmental delay and intellectual disability is present. Both the isolated and complex forms have a significant causal genetic component and submicroscopic genomic copy number variations (CNV) are the most common identifiable genetic factor in these patients. The data on microarray testing in ASD cohorts are still accumulating and novel loci are often identified; therefore, we aimed to evaluate the diagnostic efficacy of the method and the relevance of implementing it into routine genetic testing in ASD patients. A genome-wide CNV analysis using the Agilent microarrays was performed in a group of 150 individuals with an isolated or complex ASD. Altogether, 11 (7.3%) pathogenic CNVs and 15 (10.0%) variants of unknown significance (VOUS) were identified, with the highest proportion of pathogenic CNVs in the subgroup of the complex ASD patients (14.3%). An interesting case of previously unreported partial UPF3B gene deletion was identified among the pathogenic CNVs. Among the CNVs with unknown significance, four VOUS involved genes with possible correlation to ASD, namely genes SNTG2, PARK2, CADPS2 and NLGN4X. The diagnostic efficacy of aCGH in our cohort was comparable with those of the previously reported and identified an important proportion of genetic ASD cases. Despite the continuum of published studies on the CNV testing in ASD cohorts, a considerable number of VOUS CNVs is still being identified, namely 10.0% in our study.

Transcriptome Profiling Uncovers Potential Common Mechanisms in Fetal Trisomies 18 and 21.

Human trisomies have recently been investigated using transcriptomics approaches to identify the gene expression (GE) signatures characteristic of each of these specific aneuploidy conditions. We hypothesized that the viability of cells with gross genomic imbalances might be associated with the activation of resilience mechanisms that are common to different trisomies and that are reflected by specific shared GE patterns. We report in this article our microarray GE analyses of amniocytes from fetuses with viable trisomy conditions, trisomy 21 or trisomy 18, to detect such common expression signatures. Comparative analysis of significantly differentially expressed genes in trisomies 18 and 21 revealed six dysregulated genes common to both: OTUD5, ADAMTSL1, TADA2A, PPID, PIAS2, and MAPRE2. These genes are involved in ubiquitination, protein folding, cell proliferation, and apoptosis. Pathway-based enrichment analyses demonstrated that both trisomies showed dysregulation of the PI3K/AKT pathway, cell cycle G2/M DNA damage checkpoint regulation, and cell death and survival, as well as inhibition of the upstream regulator TP53. Our data collectively suggest that trisomies 18 and 21 share common functional GE signatures, implying that common mechanisms of resilience might be activated in aneuploid cells to resist large genomic imbalances. To the best of our knowledge, this is the first study to use global GE profiling data to identify potential common mechanisms in fetal trisomies. Studies of other trisomies using transcriptomics and multiomics approaches might further clarify mechanisms activated in trisomy syndromes.