Living with type I Usher syndrome: insights from patients and their parents

Balance Control Impairments in Usher Syndrome

OBJECTIVES

To explore postural disability in Usher Syndrome (USH) patients using temporal posturographic analysis to better elucidate sensory compensation strategies of deafblind patients for posture control and correlate the Activities-specific Balance Confidence (ABC) scale with posturographic variables.

DESIGN

Thirty-four genetically confirmed USH patients (11 USH1, 21 USH2, 2 USH 4) from the Otolaryngology Outpatient Clinic and 35 controls were prospectively studied using both classical and wavelet temporal analysis of center of pressure (CoP) under different visual conditions on static and dynamic platforms. The functional impact of balance was assessed with the ABC scale. Classical data in the spatial domain, Sensorial Organization Test, and frequency analysis of the CoP were analyzed.

RESULTS

On unstable surfaces, USH1 had greater CoP surface area with eyes open (38.51 ± 68.67) and closed (28.14 ± 31.64) versus controls (3.31 ± 4.60), p < 0.001 and (7.37 ± 7.91), p < 0.001, respectively. On an unstable platform, USH consistently showed increased postural sway, with elevated angular velocity versus controls with eyes open (USH1 [44.94 ± 62.54]; USH2 [55.64 ± 38.61]; controls [13.4 ± 8.57]) (p = 0.003; p < 0.001) and closed (USH1 [60.36 ± 49.85], USH2 [57.62 ± 42.36]; controls [27.31 ± 19.79]) (p = 0.002; p = 0.042). USH visual impairment appears to be the primary factor influencing postural deficits, with a statistically significant difference observed in the visual Sensorial Organization Test ratio for USH1 (80.73 ± 40.07, p = 0.04) and a highly significant difference for USH2 (75.48 ± 31.67, p < 0.001) versus controls (100). In contrast, vestibular (p = 0.08) and somatosensory (p = 0.537) factors did not reach statistical significance. USH exhibited lower visual dependence than controls (30.31 ± 30.08) (USH1 [6 ± 11.46], p = 0.004; USH2 [8 ± 14.15], p = 0.005). The postural instability index, that corresponds to the ratio of spectral power index and canceling time, differentiated USH from controls on unstable surface with eyes open USH1 (3.33 ± 1.85) p < 0.001; USH2 (3.87 ± 1.05) p < 0.002; controls (1.91 ± 0.85) and closed USH1 (3.91 ± 1.65) p = 0.005; USH2 (3.92 ± 1.05) p = 0.045; controls (2.74 ± 1.27), but not USH1 from USH2. The canceling time in the anteroposterior direction in lower zone distinguished USH subtypes on stable surface with optokinetic USH1 (0.88 ± 1.03), USH2 (0.29 ± 0.23), p = 0.026 and on unstable surface with eyes open USH1 (0.56 ± 1.26), USH2 (0.072 ± 0.09), p = 0.036. ABC scale could distinguish between USH patients and controls, but not between USH subtypes and it correlated with CoP surface area on unstable surface with eyes open only in USH1(ρ = 0.714, p = 0.047).

CONCLUSIONS

USH patients, particularly USH1, exhibited poorer balance control than controls on unstable platform with eyes open and appeared to rely more on proprioceptive information while suppressing visual input. USH2 seems to use different multisensory balance strategies that do not align as well with the ABC scale. The advanced analysis provided insights into sensory compensation strategies in USH subtypes.

Which Came First? When Usher Syndrome Type 1 Couples with Neuropsychiatric Disorders

Usher syndrome (USH) is an autosomal recessive disorder characterized by sensorineural hearing loss (HL), retinopathy, and vestibular areflexia, with variable severity. Although a high prevalence of behavioural and mental disorders in USH patients has been reported, few studies on these psychiatric and psychological issues have been conducted. This work describes the case of a 16-year-old boy affected by congenital bilateral sensorineural HL, presenting a suddenly altered behaviour concomitant with a decrease in visual acuity. To establish a molecular diagnosis, Whole-Exome Sequencing analysis was performed, detecting a pathogenetic homozygous variant (c. 5985C>A, p.(Tyr1995*)) within the CDH23 gene. CDH23 is a known USH type 1 causative gene, recently associated with schizophrenia-like symptoms and bipolar disorders. To date, no studies have provided evidence of a direct genotype-phenotype correlation between USH patients carrying CDH23 variants and mental/behavioural issues; however, considering the multiple biological functions of CDH23, it can be hypothesised that it could have a pleiotropic effect. Overall, this study highlights the relevance of a continuous clinical evaluation of USH patients, to monitor not only the disease progression, but to early detect any psychological or behavioural alterations, thus allowing a rapid implementation of therapeutic strategies aimed at improving their quality of life and well-being.

Understanding the propensity to undergo genetic testing in patients affected by inherited retinal diseases: a twelve-item questionnaire

BACKGROUND

The diagnosis of inherited retinal diseases (IRDs) can only be confirmed through genetic testing. The aim of our study is to investigate the propensity of Italian patients affected by IRDs to undergo genetic testing.

MATERIALS AND METHODS

One hundred and thirty-two patients diagnosed with IRDs referred to Italian Retina Onlus were enrolled from 1^st January 2021 to 31^th December 2021 in this cross-sectional study to answer to a twelve-item questionnaire.

RESULTS

One hundred and four patients were aware of the possibility of taking a genetic test, and 94 of them did. Most of genetically tested patients (93.6%) had been informed about advantages and limitations of genetic investigations. The most common reason for undergoing genetic testing was to gather information for their relatives, while the most frequent reason for patients not taking the test was lack of someone who encourages them to do so. Most of genetically tested patients believed that the results could aid medical research in the search for a treatment for IRDs, while who did not undergo DNA testing often did not have a clear opinion on the topic. Almost all patients (98.9%) performed the test through the Italian National Health System.

CONCLUSIONS

Our study investigated the tendency of Italian patients affected by IRDs to undergo genetic testing, highlighting the importance of educating both patients and healthcare professionals on this topic.

Interventions for children with deafblindness-An integrative review

BACKGROUND

Deafblindness is a rare condition, and its prevalence has been reported to be approximately 1 in 27 000 new-borns worldwide. For individuals with deafblindness, lifelong interventions and support are needed to be able to develop communication, be active and preserve a good quality of life. Because little is known about what kind of support and interventions can be offered to children with deafblindness, the aim was to summarize and disseminate research findings regarding this topic.

METHODS

Integrative review principles were employed. Systematic searches in eight databases and additional manual searches were conducted. The inclusion criteria were as follows: original studies published between 2000 and 2021 examining either interventions for children between 0 and 18 years of age with deafblindness or interventions aimed at children with deafblindness but offered to their relatives or professionals working with them. Studies on support for family members were also sought. Study characteristics were described, and key findings were synthesized into categories based on their similarities.

RESULTS

Of the 6268 identified original studies, 32 were included. The key outcomes from the included studies were synthesized into three categories, with two categories illustrating the goal/intention of the intervention (social interaction and communication, motivation and participation) and one focusing on or identifying the action taken to benefit the child (adaptation of the educational environment). Social interaction and communication was the dominant category, covering 24 of the 32 included studies.

CONCLUSIONS

This review concludes that there are a limited number of evaluated interventions for children with deafblindness. In many cases, the interventions were adapted to the individual child's needs, and most of them were found within the area of social interaction and communication. More research is needed to strengthen the level of evidence for interventions for children with deafblindness.

Living with Stargardt disease: insights from patients and their parents

Background: Stargardt disease (STGD), a rare, inherited macular degeneration most commonly affecting children and young adults, is a rapidly progressive disease leading to severe central vision loss. This research aimed to develop a conceptual disease model describing STGD symptoms and their impact on patients' lives.Material and Methods: Qualitative interviews were conducted with patients (juvenile and adult) and parents of children and adolescents with STGD. Interviewed subjects were enrolled through ophthalmologists from specialized eye centers in the USA and in France. Trained interviewers used semi-structured techniques to elicit concepts relevant to patients and their parents. Thematic analysis of interview transcripts led to the identification of concepts which were organized to generate a disease model.Results: A total of 21 patients (12 in the US; 9 in France) - 14 adults, 7 juveniles - and 7 parents were interviewed. The most cited ocular symptoms were photosensitivity and central vision decline. Interviewees reported limitations on Physical (e.g. difficulty with sports/physical activities), Mental (e.g. frustration and worry, reduced ability to concentrate), Social (e.g. issue with facial recognition and difficulty discussing disease) and Role (e.g. impact on driving and reading, difficulties at school/work) functioning. These impacts were, when possible, mitigated by coping strategies and support (e.g. using electronic devices, setting up routines or accepting the disease).Conclusions: This research provides an overview of symptoms experienced by patients with STGD and highlights the dramatic impact these have on patients' lives, allowing the identification of concepts of importance when evaluating new therapeutic options for STGD.