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Two sporadic cases of legionellosis occurring in consecutive years were confirmed by positive antigenuria to Legionella pneumophila serogroup 1 in individuals with limited mobility who were confined to their homes. Both cases had a history of using ultrasonic humidifiers and of low exposure to other possible sources of infection. This study was conducted through an expanded epidemiological survey and home inspection. Samples were collected from domestic hot water and humidifiers. Environmental isolates were characterised by immunoagglutination and immunofluorescence. The Dresden panel is employed for the determination of groups and subgroups of serogroup 1. The amoebae were isolated by water filtration and subsequent cultivation of the filters. Identification of the isolates was conducted through the sequencing of PCR products. In both cases, epidemiological studies identified the ultrasonic humidifiers as the probable source of infection. The presence of Legionella pneumophila was confirmed in the sanitary water installation and in the humidifiers, where high values of Legionella pneumophila serogroup 1 counts were also obtained. The isolates were characterised as Olda Oxford and Olda OLDA. Furthermore, in addition to the Legionella isolates, the presence of Vermamoeba vermiformis was also identified in samples obtained from domestic hot water and humidifiers in one of the residential addresses under investigation. It has been demonstrated that humidifiers can act as an amplification mechanism for pathogenic microorganisms when they are not cleaned and maintained correctly. This can pose a health danger, especially to people with previous respiratory pathologies, the immunosuppressed, and the elderly. Therefore, it is of the utmost importance that professionals who recommend the therapeutic use of this equipment should issue warnings regarding the importance of its correct use, cleaning, and disinfection. Finally, humidifiers should be considered in epidemiological surveys and in the study of sporadic cases. [ABSTRACT FROM AUTHOR]

Two sporadic cases of legionellosis occurring in consecutive years were confirmed by positive antigenuria to Legionella pneumophila serogroup 1 in individuals with limited mobility who were confined to their homes. Both cases had a history of using ultrasonic humidifiers and of low exposure to other possible sources of infection. This study was conducted through an expanded epidemiological survey and home inspection. Samples were collected from domestic hot water and humidifiers. Environmental isolates were characterised by immunoagglutination and immunofluorescence. The Dresden panel is employed for the determination of groups and subgroups of serogroup 1. The amoebae were isolated by water filtration and subsequent cultivation of the filters. Identification of the isolates was conducted through the sequencing of PCR products. In both cases, epidemiological studies identified the ultrasonic humidifiers as the probable source of infection. The presence of Legionella pneumophila was confirmed in the sanitary water installation and in the humidifiers, where high values of Legionella pneumophila serogroup 1 counts were also obtained. The isolates were characterised as Olda Oxford and Olda OLDA. Furthermore, in addition to the Legionella isolates, the presence of Vermamoeba vermiformis was also identified in samples obtained from domestic hot water and humidifiers in one of the residential addresses under investigation. It has been demonstrated that humidifiers can act as an amplification mechanism for pathogenic microorganisms when they are not cleaned and maintained correctly. This can pose a health danger, especially to people with previous respiratory pathologies, the immunosuppressed, and the elderly. Therefore, it is of the utmost importance that professionals who recommend the therapeutic use of this equipment should issue warnings regarding the importance of its correct use, cleaning, and disinfection. Finally, humidifiers should be considered in epidemiological surveys and in the study of sporadic cases.

Herein, we present a sporadic case of white sponge nevus (WSN) on the cheek mucosa in a 27-year-old Japanese man. A definite diagnosis of WSN was obtained using the typical clinical appearance and microscopic features of the lesions. Histopathological and cytological studies should be conducted to differentiate this condition from other oral premalignant white lesions. A molecular mutation analysis revealed a missense mutation in exon 1A of the keratin 4 gene, which is correlated with the development of WSN. Hence, genetic analysis must be performed to obtain an accurate diagnosis in sporadic cases. The temporary regression of the lesion after treatment with oral amoxicillin hydrate (AMPC) 750 mg/day indicates that antibiotics are effective in symptomatic cases.

Background: Identification of the causative genes of retinitis pigmentosa (RP) is important for the clinical care of patients with RP. However, a comprehensive genetic study has not been performed in Korean RP patients. Moreover, the genetic heterogeneity found in sensorineural genetic disorders makes identification of pathogenic mutations challenging. Therefore, high throughput genetic testing using massively parallel sequencing is needed. Results: Sixty-two Korean patients with nonsyndromic RP (46 patients from 18 families and 16 simplex cases) who consented to molecular genetic testing were recruited in this study and targeted exome sequencing was applied on 53 RP-related genes. Causal variants were characterised by selecting exonic and splicing variants, selecting variants with low allele frequency (below 1%), and discarding the remaining variants with quality below 20. The variants were additionally confirmed by an inheritance pattern and cosegregation test of the families, and the rest of the variants were prioritised using in-silico prediction tools. Finally, causal variants were detected from 10 of 18 familial cases (55.5%) and 7 of 16 simplex cases (43.7%) in total. Novel variants were detected in 13 of 20 (65%) candidate variants. Compound heterozygous variants were found in four of 7 simplex cases. Conclusion: Panel-based targeted re-sequencing can be used as an effective molecular diagnostic tool for RP. [ABSTRACT FROM AUTHOR]

Amyotrophic lateral sclerosis is a neurodegenerative disease of motor neurons with a median survival of 2 years. Most patients have no family history of amyotrophic lateral sclerosis, but current understanding of such diseases suggests there should be an increased risk to relatives. Furthermore, it is a common question to be asked by patients and relatives in clinic. We therefore set out to determine the risk of amyotrophic lateral sclerosis to first degree relatives of patients with sporadic amyotrophic lateral sclerosis attending a specialist clinic. Case records of patients with sporadic amyotrophic lateral sclerosis seen at a tertiary referral centre over a 16-year period were reviewed, and pedigree structures extracted. All individuals who had originally presented with sporadic amyotrophic lateral sclerosis, but who subsequently had an affected first degree relative, were identified. Calculations were age-adjusted using clinic population demographics. Probands (n = 1502), full siblings (n = 1622) and full offspring (n = 1545) were identified. Eight of the siblings and 18 offspring had developed amyotrophic lateral sclerosis. The unadjusted risk of amyotrophic lateral sclerosis over the observation period was 0.5% for siblings and 1.0% for offspring. Age information was available for 476 siblings and 824 offspring. For this subset, the crude incidence of amyotrophic lateral sclerosis was 0.11% per year (0.05–0.21%) in siblings and 0.11% per year (0.06–0.19%) in offspring, and the clinic age-adjusted incidence rate was 0.12% per year (0.04–0.21%) in siblings. By age 85, siblings were found to have an 8-fold increased risk of amyotrophic lateral sclerosis, in comparison to the background population. In practice, this means the risk of remaining unaffected by age 85 dropped from 99.7% to 97.6%. Relatives of people with sporadic amyotrophic lateral sclerosis have a small but definite increased risk of being affected. [ABSTRACT FROM PUBLISHER]

The results of genome-wide association studies have revealed that most human complex diseases (for example, cancer, diabetes and psychiatric disorders) are affected by a large number of variants, each of which explains a small increase in disease risk, suggesting a pattern of polygenic inheritance. At the same time, it has been argued that most complex diseases are genetically heterogeneous because many sporadic cases are observed, as well as cases with a family history. In this study, under the assumption of polygenic inheritance, we derive the expected proportion of sporadic cases using analytical methods and simulation. We show how the proportion of sporadic cases depends on disease prevalence (K) and heritability on the underlying liability scale (hL2). We predict the underlying heritability and the proportion of sporadic cases for a range of human complex diseases, and show that this proportion is typically large. For a disease with hL2=63% and K=0.4%, such as schizophrenia, >83% of proband cases are predicted to be sporadic (no affected first-, second- and third-degree relatives) in typical families (on an average, two children per couple). For the majority of these diseases, a large proportion of sporadic cases is expected under the polygenic model, implying that the observed large proportion of sporadic cases is not informative to the causal mechanism of a complex genetic disease. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to assess sex-related differences in sporadic cases of arrhythmogenic right ventricular cardiomyopathy (ARVC)., Background: Previous studies have suggested male predominance in ARVC. However, the impact of sex on the heterogeneous clinical profile and prognosis of ARVC were not fully recognized., Methods: The study population included 110 patients with ARVC who fulfilled the revised Task Force criteria (median age 48 years [interquartile range (IQR): 36 to 57 years]). All patients were sporadic cases without family history of ARVC. Male patients had a 3:1 predominance (75%). Ninety-seven patients (88%) were considered to have "definite" ARVC based on revised Task Force criteria., Results: At the initial evaluation, there were no significant sex-related differences in age, 12-lead electrocardiogram findings, late potentials by signal-averaged electrocardiogram, left ventricular ejection fraction, or right ventricular ejection fraction. During a median follow-up of 10.0 years (IQR: 5.2 to 15.6 years), 18 patients died from cardiac causes. Kaplan-Meier analysis, considering patients' lives since birth, revealed that male patients had a significantly higher risk of ventricular tachycardia/ventricular fibrillation than did female patients (56% vs. 90%, p = 0.02), whereas female patients had a significantly higher risk of heart failure (HF) death or heart transplantation (22% vs. 5%, p = 0.002). On multivariate Cox regression analysis, female sex was an independent risk factor for HF death or heart transplantation due to HF (hazard ratio: 6.29, 95% confidence interval: 1.29 to 40.2; p = 0.02)., Conclusions: Among patients with sporadic ARVC, men had a significantly higher risk of ventricular tachycardia/ventricular fibrillation, whereas women had a significantly higher risk of HF death or heart transplantation due to HF., (Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)