ATP6V0C variants impair V-ATPase function causing a neurodevelopmental disorder often associated with epilepsy

The vacuolar H+-ATPase is an enzymatic complex that functions in an ATP-dependent manner to pump protons across membranes and acidify organelles, thereby creating the proton/pH gradient required for membrane trafficking by several different types of transporters. We describe heterozygous point variants in ATP6V0C, encoding the c-subunit in the membrane bound integral domain of the vacuolar H+-ATPase, in 27 patients with neurodevelopmental abnormalities with or without epilepsy. Corpus callosum hypoplasia and cardiac abnormalities were also present in some patients. In silico modelling suggested that the patient variants interfere with the interactions between the ATP6V0C and ATP6V0A subunits during ATP hydrolysis. Consistent with decreased vacuolar H+-ATPase activity, functional analyses conducted in Saccharomyces cerevisiae revealed reduced LysoSensor fluorescence and reduced growth in media containing varying concentrations of CaCl2. Knockdown of ATP6V0C in Drosophila resulted in increased duration of seizure-like behaviour, and the expression of selected patient variants in Caenorhabditis elegans led to reduced growth, motor dysfunction and reduced lifespan. In summary, this study establishes ATP6V0C as an important disease gene, describes the clinical features of the associated neurodevelopmental disorder and provides insight into disease mechanisms.

Genetic testing in individuals with cerebral palsy

AIM To determine which patients with cerebral palsy (CP) should undergo genetic testing, we compared the rate of likely causative genetic variants from whole-exome sequencing in individuals with and without environmental risk factors. METHOD Patients were part of a convenience and physician-referred cohort recruited from a single medical center, and research whole-exome sequencing was completed. Participants were evaluated for the following risk factors: extreme preterm birth, brain bleed or stroke, birth asphyxia, brain malformations, and intrauterine infection. RESULTS A total of 151 unrelated individuals with CP (81 females, 70 males; mean age 25y 7mo [SD 17y 5mo], range 3wks-72y) participated. Causative genetic variants were identified in 14 participants (9.3%). There was no significant difference in diagnostic rate between individuals with risk factors (10 out of 123; 8.1%) and those without (4 out of 28; 14.3%) (Fisher's exact p=0.3). INTERPRETATION While the rate of genetic diagnoses among individuals without risk factors was higher than those with risk factors, the difference was not statistically significant at this sample size. The identification of genetic diagnoses in over 8% of cases with risk factors suggests that these might confer susceptibility to environmental factors, and that further research should include individuals with risk factors. What this paper adds There is no significant difference in diagnostic rate between individuals with and without risk factors. Genetic variants may confer susceptibility to environmental risk factors. Six causative variants were identified in genes not previously associated with cerebral palsy. Global developmental delay/intellectual disability is positively associated with a genetic etiology. Extreme preterm birth, stroke/brain hemorrhage, and older age are negatively associated with a genetic etiology.

Truncating variants in the SHANK1 gene are associated with a spectrum of neurodevelopmental disorders

PURPOSE

In this study, we aimed to characterize the clinical phenotype of a SHANK1-related disorder and define the functional consequences of SHANK1 truncating variants.

METHODS

Exome sequencing (ES) was performed for six individuals who presented with neurodevelopmental disorders. Individuals were ascertained with the use of GeneMatcher and Database of Chromosomal Imbalance and Phenotype in Humans Using Ensembl Resources (DECIPHER). We evaluated potential nonsense-mediated decay (NMD) of two variants by making knock-in cell lines of endogenous truncated SHANK1, and expressed the truncated SHANK1 complementary DNA (cDNA) in HEK293 cells and cultured hippocampal neurons to examine the proteins.

RESULTS

ES detected de novo truncating variants in SHANK1 in six individuals. Evaluation of NMD resulted in stable transcripts, and the truncated SHANK1 completely lost binding with Homer1, a linker protein that binds to the C-terminus of SHANK1. These variants may disrupt protein-protein networks in dendritic spines. Dispersed localization of the truncated SHANK1 variants within the spine and dendritic shaft was also observed when expressed in neurons, indicating impaired synaptic localization of truncated SHANK1.

CONCLUSION

This report expands the clinical spectrum of individuals with truncating SHANK1 variants and describes the impact these variants may have on the pathophysiology of neurodevelopmental disorders.

Is type II diabetes mellitus (NIDDM) a surgical disease?

Since February 1, 1980, 515 morbidly obese patients have undergone the Greenville gastric bypass (GGB) operation. Of these, 212 (41.2%) were euglycemic, 288 (55.9%) were either diabetic or had glucose intolerance, and 15 (2.9%) were unable to complete the evaluation. After the operation, only 30 (5.8%) patients remained diabetic (and 20 of these improved), 457 (88.7%) became and have remained euglycemic, and inadequate data prevented classification of the other 28 (5.4%). The patients who failed to return to normal glucose values were older and their diabetes was of longer duration than those who did. The effect of the GGB was not only limited to the correction of abnormal glucose levels. The GGB also corrected the abnormal levels of fasting insulin and glycosylated hemoglobin in a cohort of 52 consecutive severely obese patients with non-insulin-dependent diabetes. The GGB effectively controls weight. If morbid obesity is defined as 100 pounds over ideal body weight, 89% of the patients are no longer "morbidly" obese within 2 years. In most patients, the control of the weight has been well maintained during the 11 years of follow-up; most of the upward creep in weight of 20.8% between 24 and 132 months was from the 49 (9.5%) patients who had staple line breakdowns between the large and small gastric pouches. Non-insulin-dependent diabetes, previously considered a chronic unrelenting disease, can be controlled in the severely obese by the gastric bypass. Whether the correction of glucose metabolism affects the complications of diabetes is unknown. Whether the gastric bypass should be considered for patients with advanced non-insulin-dependent diabetes but who are not severely obese deserves consideration. The GGB has an unacceptably high rate of staple line failure. Accordingly, the authors have recently changed their procedure to one that divides the stomach rather than partitions it with staples.

Reliability and validity of the Work-Related Strain Inventory among health professionals

This article provides evidence from five samples of different health professionals (family physicians, emergency medical technicians, hospital nurses, flight nurses, and emergency medicine residents) for the reliability and validity of the Work-Related Strain Inventory (WRSI). The inventory consists of 18 items and was designed to measure perceptions of strain in occupational settings. Internal consistency reliability ranged from .85 to .90 and, as predicted, was correlated with the Maslach Burnout Inventory and measures of depression, role ambiguity, job satisfaction, and work-group functioning. When compared with different measures of depression symptoms (eg, Zung Self-Rating of Depression Scale, Center for Epidemiologic Studies Depression Scale), the Work-Related Strain Inventory was found to measure a different and independent construct. This inventory, a short, easily administered measure with good reliability, may be useful for appraising levels of work-related strain in behavioral and organizational models of the consequences of stress in different work environments.

Long-term studies of mental health after the Greenville gastric bypass operation for morbid obesity

From February 1, 1980, to May 1, 1989, 462 patients underwent the Greenville gastric bypass at the East Carolina University School of Medicine. The operation effectively maintained satisfactory weight loss after 9 years (mean weight preoperatively, 293 lbs; at 24 months, 179 lbs; at 96 months, 194 lbs). The gastric bypass favorably affected non-insulin-dependent diabetes, hypertension, and physical and role functioning. In the most recent 157 patients, our studies were extended to study the effects of the gastric bypass on mental health. The significant improvements in mental health indices that were observed 6 and 12 months after surgery eroded by the end of 2 years. This return of the mental health indices to the preoperative status, plus the late occurrence of 3 suicides and 2 deaths from alcohol abuse among the total 462 patients, suggest that long-term follow-up and continued emotional support are essential ingredients for successful bariatric surgery.

[Primary and secondary reconstruction of the frontal sinus using the titanium screen system]

The objective of surgically maintaining shape and lumen after frontal sinus injuries can be achieved by using various types of osteosynthesis and reconstructive materials. In cases with extensive fracture defects we recommend alloplastic anterior wall reconstruction using titanium screens as an alternative to conventional procedures.

Mental status assessment in the elderly

Mental status testing is an essential element of evaluating elderly patients. A structured examination often helps identify the etiology of symptoms that are responsible for changes in patient behavior, that lead to family stress, but that are otherwise not indicative of cognitive dysfunction. A structured mental status examination is also helpful in distinguishing cognitive changes caused by dementia, delirium, and depression. This article examines the steps in mental status assessment and the commonly used assessment instruments. The experience of a family medicine ambulatory multidisciplinary evaluation service in mental status testing is discussed.

Combined training in procedural and behavioral counseling skills

A combined training experience in behavioral counseling skills and office procedural skills was developed for second-year family medicine residents. Residents were relieved of other clinical responsibilities during the month this curriculum was presented, thus avoiding problems of competition for the residents' attention. By having all second-year residents together, faculty teaching time was efficiently used, and the haphazard results from relying on faculty-resident precepting experiences in the family practice center to provide training in these areas was avoided. Behavioral counseling and office procedural skills training were found to be complementary in areas of content, in teaching methods, and in maintaining variety and interest in the training experience. Pre- and post-testing of residents revealed a significant increase in knowledge of cognitive aspects of these two content areas at the end of the experience.

Organizational characteristics, occupational stress, and mental health in nurses

A model of occupational stress in hospital nurses was developed and tested. The model used measures of organizational climate, supervisor behavior, and work group relations as predictors of the quantity of role ambiguity perceived by nurses. Data were collected on 232 hospital nurses working in a rural community hospital affiliated with a medical school. Results confirmed the hypothesized structural model. Organizational climate, supervisor behavior, and work group relations directly influenced role perception. Increased role ambiguity led to decreased job satisfaction and increased perceived stress. The organizational environment directly influenced job stress. Occupational stress exerted a strong direct influence on the development of depressive symptoms in nurses.

Physician suicide in North Carolina

Previous research suggests that physicians are two to three times as prone to suicide than the general population. Review of North Carolina death certificates from 1978 to 1982 showed that the physician suicide rate is not substantially different from that of the white male population aged 25 years or older. Old age, divorce, and death of a spouse are associated with the highest suicide rates among physicians. Firearms and drugs are the most common suicidal methods. Depression, substance abuse, and retirement are significantly associated with suicide risk. Physicians need to recognize the existence of increased suicide risk with age and retirement.

Life skill training: psychoeducational training as mental health treatment

Fifty-four patients of a Veterans Administration Medical Center were assigned to either a life-skill training program that emphasized psychoeducational instruction and skill building or to a group counseling control condition. Subjects assigned to life-skill training were provided with 28 hours of instruction in interpersonal communication, purpose in life problem solving, and physical fitness/health maintenance. Control subjects received equal time engaged in psychiatric treatment that emphasized the analysis and exploration of personal problems, but with no direct coping skill training. Significant differences between the two groups were found on measures of interpersonal communication and meaningful purpose in life. Both groups received lower staff ratings on psychopathological behavior and demonstrated improvement on ratings of health and physical fitness upon completion of treatment. Twelve- and 24-month follow-up data that include rehospitalization rates are presented for each group.

Occupational stress, social support, and depression

A model of occupational stress, social support, locus of control, and depression among family physicians was developed. Two hundred and ten family physicians were administered measures of occupational stress, social support, locus of control, and depression. The hypothesized model was evaluated using structural equation models (LISREL). Results indicate that occupational stress exerts a direct effect on depression. This relationship is moderated directly by family social and emotional support and indirectly by the influence of locus of control on family social support. Support from peers was not significantly related to depression. Findings suggest that individuals with a strong sense of personal control also possess beneficial support systems in the presence of stressful situations.

Use of orally administered diazepam in the reduction of dental anxiety

A double-blind randomized clinical trial of the effectiveness of orally administered diazepam in reducing dental anxiety was conducted. Forty-one subjects were assigned to a diazepam or placebo group and tested, using the Dental Fear Survey and State-Trait Anxiety Inventory. Diazepam was effective in reducing anxiety scores but not dental fear scores.

Professional stress and the practicing family physician

To investigate the physician stress syndrome among practicing family physicians, we mailed a questionnaire regarding stress, depression, locus of control, social and peer support, and medical practice characteristics to a sample of practicing family physicians. The response rate was 64%. Significant positive correlations were found between perceived stress in medical practice, depression, and external locus of control. Family physicians who reported increased levels of stress also had greater depression and an increased tendency to blame external agents in their environment for personal stress. Decreased levels of perceived stress tended to be associated with higher scores on indices of family and physician-peer support. Family practitioners reported high levels of family and peer support.