Heterozygous and Homozygous Variants in SORL1 Gene in Alzheimer's Disease Patients: Clinical, Neuroimaging and Neuropathological Findings

In the last few years, the SORL1 gene has been strongly implicated in the development of Alzheimer’s disease (AD). We performed whole-exome sequencing on 37 patients with early-onset dementia or family history suggestive of autosomal dominant dementia. Data analysis was based on a custom panel that included 46 genes related to AD and dementia. SORL1 variants were present in a high proportion of patients with candidate variants (15%, 3/20). We expand the clinical manifestations associated with the SORL1 gene by reporting detailed clinical and neuroimaging findings of six unrelated patients with AD and SORL1 mutations. We also present for the first time a patient with the homozygous truncating variant c.364C>T (p.R122*) in SORL1, who also had severe cerebral amyloid angiopathy. Furthermore, we report neuropathological findings and immunochemistry assays from one patient with the splicing variant c.4519+5G>A in the SORL1 gene, in which AD was confirmed by neuropathological examination. Our results highlight the heterogeneity of clinical presentation and familial dementia background of SORL1-associated AD and suggest that SORL1 might be contributing to AD development as a risk factor gene rather than as a major autosomal dominant gene.

Insecticide susceptibility status in Mexican populations of Stegomyia aegypti (= Aedes aegypti): a nationwide assessment

In Mexico, mosquito vector-borne diseases are of public health concern as a result of their impact on human morbidity and mortality. The use of insecticides against adult mosquitoes is one of the most common ways of controlling mosquito population densities. However, the use of these compounds has resulted in the development of insecticide resistance. The aim of this study was to estimate susceptibility to six pyrethroids, two carbamates and two organophosphates in Mexican populations of Stegomyia aegypti (Linnaeus, 1762) (= Aedes aegypti) (Diptera: Culicidae) mosquitoes. Bottle insecticide susceptibility tests, with 1 h exposure, were performed on adult mosquitoes from 75 localities across 28 states. At 30 min of exposure, the proportion of fallen mosquitoes was recorded. After 60 min of exposure, mosquitoes were recovered in non-treated containers and mortality was determined at 24 h after the set-up of the experiment. In general, the carbamate insecticides represented the most effective group in terms of the proportion of mosquitoes fallen at 30 min (72-100%) and 24-h mortality (97-100%). High and widespread resistance to pyrethroids Types I and II and, to a lesser extent, to organophosphates was observed. Insecticide susceptibility among and within states was highly variable.

[Phenotypic variability of the 1q21.1 microdeletion syndrome in members of the same family: relevance of detection of neuropsychiatric disorders for diagnosis of genetic syndromes]

INTRODUCTION

1q21.1 microdeletion syndrome is a caused by a recurrent deletion of the 1q21.1 copy-number variant, which spans 800 kb and includes at least seven genes. It is associated with a variable phenotype. Neuropsychiatric abnormalities have been previously described in many of the previously reported cases, but its true prevalence is unknown.

AIM

To illustrate the phenotypic variability in 1q21.1 microdeletion syndrome.

CASE REPORTS

Four individuals of the same kindred harboring a 1.74-Mb deletion within 1q21.1 are included. In our patients a heterogeneous phenotype is recognized. Neuropsychiatric disorders or more specifically impulse control disorders were common to all the four cases that we present.

CONCLUSIONS

1q21.1 microdeletion syndrome is phenotypically heterogeneous even among members of the same family. Behavioral or neuropsychiatric abnormalities are frequent. Paucisymptomatic forms with individuals presenting exclusively psychiatric disorders have been identified.

Chromosomal anomalies in cryptorchidism and hypospadias

PURPOSE

We studied the incidence of chromosomal anomalies in patients with cryptorchidism and hypospadias to determine the value of routine karyotyping in this population.

MATERIALS AND METHODS

Blood samples from 984 patients with cryptorchidism and/or hypospadias were studied for chromosome analysis.

RESULTS

Chromosomal anomalies were detected in 27 of the 916 patients (2.94%) with cryptorchidism and in 7 of the 100 (7%) with hypospadias. There were chromosomal aberrations in 13 of the 706 patients (1.84%) with isolated cryptorchidism (no additional congenital abnormalities) and in 14 of the 210 (6.67%) with cryptorchidism with associated anomalies. We identified normal karyotypes in 26 patients with isolated hypospadias, although 7 of the 74 (9.46%) with hypospadias and additional abnormalities had chromosomal aberrations.

CONCLUSIONS

It is important to perform karyotyping in these patients, mainly when they show associated abnormalities other than cryptorchidism or hypospadias. However, cost-benefit analysis must be done in each case.

Chromosomal anomalies in cryptorchidism and hypospadias

PURPOSE

We studied the incidence of chromosomal anomalies in patients with cryptorchidism and hypospadias to determine the value of routine karyotyping in this population.

MATERIALS AND METHODS

Blood samples from 984 patients with cryptorchidism and/or hypospadias were studied for chromosome analysis.

RESULTS

Chromosomal anomalies were detected in 27 of the 916 patients (2.94%) with cryptorchidism and in 7 of the 100 (7%) with hypospadias. There were chromosomal aberrations in 13 of the 706 patients (1.84%) with isolated cryptorchidism (no additional congenital abnormalities) and in 14 of the 210 (6.67%) with cryptorchidism with associated anomalies. We identified normal karyotypes in 26 patients with isolated hypospadias, although 7 of the 74 (9.46%) with hypospadias and additional abnormalities had chromosomal aberrations.

CONCLUSIONS

It is important to perform karyotyping in these patients, mainly when they show associated abnormalities other than cryptorchidism or hypospadias. However, cost-benefit analysis must be done in each case.