GNB1-Related Rod-Cone Dystrophy: A Case Report

Introduction

The GNB1 (guanine nucleotide-binding protein, β1) gene encodes for the ubiquitous β1 subunit of heterotrimeric G proteins, which are associated with G-protein-coupled receptors (GPCRs). GNB1 mutations cause a neurodevelopmental disorder characterized by a broad clinical spectrum. A novel variant has recently been confirmed in a case of rod-cone dystrophy.

Case Presentation

We describe the second confirmed case of a classical rod-cone dystrophy associated with a mutation located in exon 6 of GNB1 [NM_002074.5:c.217G>C, p.(Ala73Pro)] in a 56-year-old patient also presenting mild intellectual disability, attention deficit/hyperactivity disorder, and truncal obesity.

Conclusion

This paper confirms the role of GNB1 in the pathogenesis of a classic rod-cone dystrophy and highlights the importance of including this gene in the genetic analysis panel for inherited retinal diseases.

Genetics of Retinitis Pigmentosa and Other Hereditary Retinal Disorders in Western Switzerland

INTRODUCTION

Mutational screening of inherited retinal disorders is prerequisite for gene targeted therapy. Our aim was to report and analyze the proportions of mutations in inherited retinal disease (IRD)-causing genes from a single center in Switzerland in order to describe the distribution of IRDs in Western Switzerland.

METHODS

We conducted a retrospective study of patient records. Criteria for inclusion were residence in Western Switzerland for patients and relatives presenting a clinical diagnosis of IRDs and an established molecular diagnosis managed by the genetics service of the Jules-Gonin Eye Hospital (JGEH) of Lausanne between January 2002 and December 2022. We initially investigated the IRD phenotypes in all patients (full cohort) with a clinical diagnosis, then calculated the distribution of IRD gene mutations in the entire cohort (genetically determined cohort). We analyzed a sub-group that comprised pediatric patients (≤18 years of age). In addition, we calculated the distribution of gene mutations within the most represented IRDs. Comprehensive gene screening was performed using a combined approach of different generation of DNA microarray analysis, direct sequencing, and Sanger sequencing.

RESULTS

The full cohort comprised 899 individuals from 690 families with a clinical diagnosis of IRDs. We identified 400 individuals from 285 families with an elucidated molecular diagnosis (variants in 84 genes) in the genetically determined cohort. The pediatric cohort included 89 individuals from 65 families with an elucidated molecular diagnosis. The molecular diagnosis rate for the genetically determined cohort was 58.2% (family ratio) and the 5 most frequently implicated genes per family were ABCA4 (11.6%), USH2A (7.4%), EYS (6.7%), PRPH2 (6.3%), and BEST1 (4.6%). The pediatric cohort had a family molecular diagnosis rate of 64.4% and the 5 most common mutated genes per family were RS1 (9.2%), ABCA4 (7.7%), CNGB3 (7.7%), CACNA1F (6.2%), CEP290 (4.6%).

CONCLUSIONS

This study describes the genetic mutation landscape of IRDs in Western Switzerland in order to quantify their disease burden and contribute to a better orientation of the development of future gene targeted therapies.

Coats-like Vasculopathy in Inherited Retinal Disease: Prevalence, Characteristics, Genetics, and Management

PURPOSE

To describe the largest, most phenotypically and genetically diverse cohort of patients with inherited retinal disease (IRD)-related Coats-like vasculopathy (CLV).

DESIGN

Multicenter retrospective cohort study.

PARTICIPANTS

A total of 67 patients with IRD-related CLV.

METHODS

Review of clinical notes, ophthalmic imaging, and molecular diagnosis from 2 international centers.

MAIN OUTCOME MEASURES

Visual function, retinal imaging, management, and response to treatment were evaluated and correlated.

RESULTS

The prevalence of IRD-related CLV was 0.5%; 54% of patients had isolated retinitis pigmentosa (RP), 21% had early-onset severe retinal dystrophy, and less frequent presentations were syndromic RP, sector RP, cone-rod dystrophy, achromatopsia, PAX6-related dystrophy, and X-linked retinoschisis. The overall age of patients at CLV diagnosis was 30.7 ± 16.9 years (1-83). Twenty-one patients (31%) had unilateral CLV, and the most common retinal features were telangiectasia, exudates, and exudative retinal detachment (ERD) affecting the inferior and temporal retina. Macular edema/schisis was observed in 26% of the eyes, and ERD was observed in 63% of the eyes. Fifty-four patients (81%) had genetic testing, 40 of whom were molecularly solved. Sixty-six eyes (58%) were observed, 17 eyes (15%) were treated with a single modality, and 30 eyes (27%) had a combined approach. Thirty-five eyes (31%) were "good responders," 42 eyes (37%) were "poor responders," 22 eyes (19%) had low vision at baseline and were only observed, and 12 eyes (11%) did not have longitudinal assessment. Twenty-one observed eyes (62%) responded well versus 14 (33%) treated eyes. Final best-corrected visual acuity was significantly worse than baseline (P = 0.002); 40 patients (60%) lost 15 ETDRS letters or more over follow-up in 1 or both eyes, and 21 patients (31%) progressed to more advanced stages of visual impairment.

CONCLUSIONS

Inherited retinal disease-related CLV is rare, sporadic, and mostly bilateral; there is no gender predominance, and it can occur in diverse types of IRD at any point of the disease, with a mean onset in the fourth decade of life. Patients with IRD-related CLV who have decreased initial visual acuity, ERD, CLV changes affecting 2 or more retinal quadrants, and CRB1-retinopathy may be at higher risk of a poor prognosis.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Abstract P2-04-01: HER2 Status as Predictor of Mammographic Screening Detection: Comparison of Interval-and Screen-Detected Breast Cancers

Background: To determine whether markers of poor prognosis are associated with risk of breast cancer diagnosis in the interval between screening examinations, we estimated the effect of the mode of detection on distribution of breast cancer molecular subtypes using population cancer registry data.

Material and Methods: Subjects (n = 641) comprised all breast cancers systematically collected by the Cancer Registry of Parma Province and diagnosed in women aged 50-69, from 2004 to 2007. These included 370 screen-detected and 271 symptomatic breast cancers (63 women with interval cancers and 208 who had not attended screening). We used logistic regression to determine whether interval cancers were associated with selected clinical and biologic characteristics. We also estimated the relative risk of cause-specific fatality and disease-free survival (DFS) by each resulting predictive factor (screen-detected compared to either symptomatic or interval cancers).

Results: Interval-detected cancers occurred more in younger women and were of more advanced tumor stage than screen-detected cancers. In unconditional logistic regression models adjusted for age and tumor stage, tumors with high histologic grade (odds ratio[OR] = 2.2; 95% CI =1.0-5.4), high proliferation rate (OR =2.7; 95% CI =1.5-4.8), or positive HER2 status (OR =2.6; 95% CI =1.3-5.1) were more likely to surface in the interval between screening examinations. After adjusting for various potential biases, women with screen-detected breast cancer had a substantial survival advantage over those with symptomatic breast cancer. In a multivariate model, positive HER2 status independently predicted poor DFS when the mode of cancer detection was included as covariate in addition to age, histologic grade, proliferation rate, and tumor stage. Conclusions: This is the first population-based cancer registry study demonstrating that HER2-positive tumors account for a substantial proportion of mammographic screening failure to detect breast cancer. Our data indicate that molecular subtype distribution of screen-detected breast cancer differs from that of interval cancers and accounts in part for the better outcome of screen-detected cancer.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-04-01.

[Clinically non-palpable lesions of the breast: radiologic features, biologic factors, and surgical strategy]

The use of mammography for early detection of breast cancer showed an increased detection of non-palpable breast-lesions (NPBL). The authors evaluate the radiologic findings, the biological factors and the surgical approach, trough the personal experience and the literature, for a correct treatment of these lesions.

US and CT findings of secondary neoplasms of the thyroid--a pictorial essay

Although clinical series report a low (3%) incidence of metastases to the thyroid gland, autoptic studies have showed occurrences as high as 17%, probably because of the high vascularization of the thyroid. We selected 9 patients who had pathologically proven thyroid metastases at CT and US, during follow-up for a known primary neoplasm. The most common originating neoplastic primaries include mostly those that generally give rise to blood-borne metastases such as breast and lung cancers, mucoid adenocarcinoma of the stomach, colon cancer and renal cancer, as well as melanoma and leiomyosarcoma. Because of its diffusion, sensitivity, and noninvasiveness, ultrasonography can justifiably be introduced in the staging protocols of those neoplasm that more frequently give blood-borne metastases to the thyroid, but a US-guided biopsy is warranted for hypoechoic or otherwise suspicious nodules. This holds particularly true in disease-free patients or previously diagnosed with generally slow-growing malignancies (breast or kidney), since the secondary localization, often metachronous in our experience, may be effectively managed surgically. CT features, on the other hand, are extremely variable and are directly dependent on the histology of the primary lesion, as well as the size of the secondary lesions.

Synthesis, DNA interaction and antineoplastic activity of semicarbazone derivatives

A number of antineoplastic agents including procarbazine and bisantrene derive from hydrazine, but so far none have been developed from semicarbazide. In order to assay active minimal structures, thirteen new compounds were prepared by replacing hydrogen atoms in semicarbazone amine group by alkylamine moieties, employing an improved procedure. DNA binding was evaluated by treatment of a drug solution with DNA-cellulose complex and further measurement of remaining drug by UV spectroscopy and the affinity observed to range from medium to weak. On testing these compounds against human neoplastic cell lines, only a nitroderivative proved active on CNS and Breast cell lines at 10(-4) M. This member was studied by cyclic voltammetry.

[Quality control of stereotaxic cytologic test of non-palpable lesions of the breast]

The authors compare the accuracy and other indicators of efficiency of ten centers (1,784 total cases) performing stereotaxic cytology and adhering to a multicentric study aimed at validating a quality control system for this diagnostic procedure. The results from single centers were compared with average results. No significant differences were observed for most centers from the average sensitivity (86%), specificity (91%), positive predictive value of a dubious (57%) or positive (96%) cytologic report, inadequacy rate on malignant (6%) or benign (11%) lesions, and benign/malignant biopsy ratio (0.63). Some significant differences from the average values indicated the need for some centers to review different phases of the diagnostic process, namely to verify the accuracy of sampling sites (low sensitivity with good specificity and predictivity), to review the criteria for cytologic diagnosis (specificity less than 90%, low predictive value or higher predictive value for dubious compared with positive reports), to optimize the impact of cytology on the final decision (lack of reduction of benign/malignant biopsy ratio). Periodic check of the above parameters is proposed as a routine quality control of this diagnostic procedure.