Extension of the Pompe mutation database by linking disease‐associated variants to clinical severity

Pompe disease is an autosomal recessive lysosomal storage disorder caused by disease‐associated variants in the acid alpha‐glucosidase (GAA) gene. The current Pompe mutation database provides a severity rating of GAA variants based on in silico predictions and expression studies. Here, we extended the database with clinical information of reported phenotypes. We added additional in silico predictions for effects on splicing and protein function and for cross reactive immunologic material (CRIM) status, minor allele frequencies, and molecular analyses. We analyzed 867 patients and 562 GAA variants. Based on their combination with a GAA null allele (i.e., complete deficiency of GAA enzyme activity), 49% of the 422 disease‐associated variants could be linked to classic infantile, childhood, or adult phenotypes. Predictions and immunoblot analyses identified 131 CRIM negative and 216 CRIM positive variants. While disease‐associated missense variants were found throughout the GAA protein, they were enriched up to seven‐fold in the catalytic site. Fifteen percent of disease‐associated missense variants were predicted to affect splicing. This should be confirmed using splicing assays. Inclusion of clinical severity rating in the Pompe mutation database provides an invaluable tool for diagnosis, prognosis of disease progression, treatment regimens, and the future development of personalized medicine for Pompe disease.     

Maternal nutrient intake and fetal gastroschisis: A case‐control study

Fetal gastroschisis is a paraumbilical abdominal wall defect with herniation of the abdominal organs. This multifactorial malformation occurs in young pregnant women, and the underlying cause of the disease remains unknown; however, nutritional factors may play a role in its development. This case‐control study explored the association of maternal nutrient intake with the occurrence of gastroschisis. The gastroschisis group (GG) comprised 57 pregnant women with fetuses with gastroschisis, and the control group (CG) comprised 114 pregnant women with normal fetuses matched for maternal age, gestational age, and preconception body mass index classification. Nutritional assessments related to the preconception period were obtained using the food consumption frequency questionnaire, and nutrient intakes were calculated using nutrition programs. The median daily calorie intake was higher (2,382.43 vs. 2,198.81; p = .041) in the GG than in the CG. The median intake of methionine (763.89 vs. 906.34; p = .036) and threonine (1,248.34 vs. 1,437.01; p = .018) was lower in the GG than in the CG. Pregnant women with fetuses with gastroschisis have a diet characterized by higher calorie intake and lower levels of essential amino acids (methionine and threonine) during the preconception period than pregnant women with normal fetuses.     

High levels of serum glycans monovalent IgG immune complexes detected by dissociative ELISA in experimental visceral leishmaniasis

Visceral leishmaniasis (VL) is epidemic in Brazil with an increasing incidence of human cases and canine reservoirs, with host hypergammaglobulinemia. Conventional enzyme-linked immunosorbent assay (cELISA) based on several parasitic antigens is the main method for diagnosis and indication of treatment. Dissociative ELISA (dELISA) uses acidic treatment to free immunoglobulin G (IgG) from immune complexes, and its use revealed a significant positive fraction of suspected cases with negative serology. Looking for small molecules or haptens that block IgG antibodies, we purified by molecular exclusion chromatography, 1000–3000 MW molecules from promastigote soluble extract, mostly oligosaccharides comprising 6–13 sugar residues using MALDI-TOF analysis. Glycan-BSA complex (GBC) was constructed by conjugating promastigote glycans to BSA molecules, allowing their use in the solid support in cELISA or dELISA. Sera from experimentally infected hamsters showed higher levels of blocked monomeric IgG during infection, mostly against GBC, which was also present in lower concentrations in the promastigote soluble extract dELISA. Those data show that most of the specific monomeric IgG in serum are blocked by haptens composed by glycans produced by the parasite, better detected in the high dilution of sera in the dELISA assays. dELISA is a useful technique for detecting blocked monomeric antibodies that could have difficult clearance from blood, which could result in hypergammaglobulinemia.     

Variable sources of Bk virus in renal allograft recipients

BK virus is the causative agent of polyomavirus-associated nephropathy, a major cause of kidney transplant failure affecting 1%-10% of recipients. Previous studies that investigated the viral source on the kidney recipient pointed that the donor is implicated in the origin of human polyomavirus BK (BKPyV) infection in recipients, but giving the low genetic variability of BKPyV this subject is still controversial. The aim of this study was to determine if BKPyV replicating in kidney recipients after transplantation is always originated from the donor. Urine and blood samples from 68 pairs of living donors and kidney recipients who underwent renal transplantation from August 2010-September 2011 were screened for BKPyV by real time polymerase chain reaction. Only three recipients presented viremia. When both donors and recipients were BKPyV positive, a larger fragment of VP1 region was obtained and sequenced to determine the level of similarity between them. A phylogenetic tree was built for the 12 pairs of sequences obtained from urine and high level of similarity among all sequences was observed, indicating that homology inferences for donor and recipient viruses must be cautiously interpreted. However, a close inspection on the donor-recipient pairs sequences revealed that 3 of 12 pairs presented considerably different viruses and 4 of 12 presented mixed infection, indicating that the source of BKPyV infection is not exclusively derived from the donor. We report that about 60% of the renal recipients shed BKPyV genetically distinct from the donor, confronting the accepted concept that the donor is the main source of recipients’ infection.     

Molecular epidemiology and host genetics of norovirus and rotavirus infections in Portuguese elderly living in aged care homes

Norovirus (NoV) and rotavirus group A (RVA) are major agents of acute gastroenteritis worldwide. This study aimed to investigate their epidemiological profile in Portuguese elderly living in long-term care facilities and to assess the host genetic factors mediating infection susceptibility. From November 2013 to June 2015, 636 faecal specimens from 169 elderly, mainly asymptomatic, living in nursing homes in Greater Lisbon and Faro district, Portugal, were collected. NoV and RVA were detected by real-time polymerase chain reaction and NoV genotyped by phylogenetic analysis. NoV detection rate was 7.1% (12 of 169). Three GI.3 and one GII.6 strains were genotyped. RVA detection rate was 3.6% (6 of 169), exclusively in asymptomatic individuals. Host genetic factors associated with infection susceptibility were described on 250 samples by saliva-based enzyme-linked immunosorbent assays. The Lewis-negative phenotype was 8.8% (22 of 250) and the rate of nonsecretors was 16.8% (42 of 250). Association to NoV and RVA infection was performed in the subgroup of individuals (n = 147) who delivered both faecal and saliva samples. The majority of NoV- and RVA-positive individuals (90.9% and 83.3%, respectively) were secretor-positive, with Lewis B phenotype. In a subset of individuals, FUT2 and FUT3 genes were genotyped to assess mutations and validate the secretor and Lewis phenotypes. All sequenced nonsecretors were homozygous for FUT2 nonsense mutation G428A. In this study, low detection rates of NoV and RVA infections were found during two winter seasons. However, even in the absence of any outbreak, the importance of finding these infections in a nonepidemic situation in long-term care facilities may have important implications for infection control.     

Hepatitis C virus genotypes in hemodialysis patients in Angola

To our knowledge, there are no published data on hepatitis C virus (HCV) genotypes in Angola. This study aimed at assessing the distribution of HCV genotypes in seropositive hemodialysis patients in Luanda. Among 51 HCV-positive subjects included, viremia was detected in 27 (53%). HCV genotyping was performed by bidirectional sequencing of the 5'-untranslated region by the Sanger method. HCV genotype 4 was largely predominant (20 cases; 74%), followed by genotypes 1b (5 cases; 18.5%), 1a and 2 (one case each; 3.7%). These results suggest that the distribution of HCV genotypes in Angola is similar to that reported from other Central African countries.     

The impact of descriptive norms on motivation to participate in cancer screening – Evidence from online experiments

ObjectiveThe current study tested in two online experiments whether manipulating normative beliefs about cancer screening uptake increases intention to attend colorectal screening among previously disinclined individuals.Methods2461 men and women from an Internet panel (Experiment 1 N = 1032; Experiment 2, N = 1423) who initially stated that they did not intend to take up screening were asked to guess how many men and women they believe to get screened for colorectal cancer. Across participants, we varied the presence/absence of feedback on the participant’s estimate, as well as the stated proportion of men and women doing the screening test.ResultsAcross the two experiments, we found that receiving one of the experimental messages stating that uptake is higher than estimated significantly increased the proportion of disinclined men and women becoming intenders. While, we found a positive relationship between the communicated uptake and screening intentions, we did not find evidence that providing feedback on the estimate has an added benefit.ConclusionScreening intention can be effectively manipulated through a high uptake message.Practice implicationsCommunication of high screening uptake is an easy and effective way to motivate disinclined individuals to engage in colorectal cancer screening.