Filamin-A-interacting protein 1 (FILIP1) is a structural protein that is involved in neuronal and muscle function and integrity and interacts with FLNa and FLNc. Pathogenic variants in filamin-encoding genes have been linked to neurological disorders (FLNA) and muscle diseases characterized by myofibrillar perturbations (FLNC), but human diseases associated with FILIP1 variants have not yet been described. Here, we report on five patients from four unrelated consanguineous families with homozygous FILIP1 variants (two nonsense and two missense). Functional studies indicated altered stability of the FILIP1 protein carrying the p.[Pro1133Leu] variant. Patients exhibit a broad spectrum of neurological symptoms including brain malformations, neurodevelopmental delay, muscle weakness and pathology and dysmorphic features. Electron and immunofluorescence microscopy on the muscle biopsy derived from the patient harbouring the homozygous p.[Pro1133Leu] missense variant revealed core-like zones of myofibrillar disintegration, autophagic vacuoles and accumulation of FLNc. Proteomic studies on the fibroblasts derived from the same patient showed dysregulation of a variety of proteins including FLNc and alpha-B-crystallin, a finding (confirmed by immunofluorescence) which is in line with the manifestation of symptoms associated with the syndromic phenotype of FILIP1opathy. The combined findings of this study show that the loss of functional FILIP1 leads to a recessive disorder characterized by neurological and muscular manifestations as well as dysmorphic features accompanied by perturbed proteostasis and myopathology.
Ezrin, radixin and moesin, which are strongly expressed in the Schwann cell microvilli, are putative targets for autoantibodies in acute or chronic inflammatory demyelinating polyneuropathy (AIDP or CIDP). An association between anti-moesin IgG antibodies and cytomegalovirus-related AIDP has been postulated. None of 41 AIDP patients, including 8 cytomegalovirus-related AIDP patients, and 23 CIDP had IgG or IgM antibodies to ezrin, radixin and moesin; whereas, one patient with cytomegalovirus-related AIDP had anti-ezrin IgM antibodies. Ezrin, radixin and moesin are unlikely targets for autoantibodies in AIDP and CIDP, and the association of anti-moesin antibodies with cytomegalovirus-related AIDP was not confirmed.
Charcot-Marie-Tooth (CMT) disease is a form of inherited peripheral neuropathy that affects motor and sensory neurons. To identify the causative gene in a consanguineous family with autosomal recessive CMT (AR-CMT), we employed a combination of linkage analysis and whole exome sequencing. After excluding known AR-CMT genes, genome-wide linkage analysis mapped the disease locus to a 7.48-Mb interval on chromosome 14q32.11-q32.33, flanked by the markers rs2124843 and rs4983409. Whole exome sequencing identified two non-synonymous variants (p.T40P and p.H915Y) in the AHNAK2 gene that segregated with the disease in the family. Pathogenic predictions indicated that p.T40P is the likely causative allele. Analysis of AHNAK2 expression in the AR-CMT patient fibroblasts showed significantly reduced mRNA and protein levels. AHNAK2 binds directly to periaxin which is encoded by the PRX gene, and PRX mutations are associated with another form of AR-CMT (CMT4F). The altered expression of mutant AHNAK2 may disrupt the AHNAK2-PRX interaction in which one of its known functions is to regulate myelination.
The aim of this study is to investigate the potential correlation between the expression of phosphorylated glycogen synthase kinase-3beta (phospho-GSK-3beta) and beta-catenin, and the mutations of beta-catenin gene at the consensus GSK-3beta phosphorylation site. The reason for this approach is to gain a better understanding of the molecular mechanisms of hepatocarcinogenesis in Malaysia. The expression of phospho-GSK-3beta and beta-catenin by immunohistochemistry and the mutations of beta-catenin were studied in 23 hepatocellular carcinoma (HCC) and surrounding tissues. Overexpression of phospho-GSK-3beta and beta-catenin was found in 12/23 (52.2%) and 13/23 (56.5%) in HCC tissues, 6/23 (26.1%) and 9/23 (39.1%) in surrounding tissues, respectively. Overexpression of beta-catenin in HCC tissues compared to the surrounding liver tissue was found to be higher in HCC tissues (p=0.015). In addition, we found that the expression of phospho-GSK-3beta was related with the accumulation of beta-catenin in surrounding tissues (p<0.05). The expression of phospho-GSK-3beta and its association with the development of HCC is reported for the first time. In addition, this is the first report from Malaysia which shows that there are no mutations at the GSK-3beta consensus phosphorylation sites on beta-catenin gene in all 23 paired HCC and surrounding tissues. This result differed from HCC in geographical areas with high aflatoxin exposure.
Atrial septal defect (ASD) is one of the most common congenital heart defects diagnosed in children. Sarcomeric genes has been attributed to ASD and knockdown of MYH3 functionally homologues gene in chick models indicated abnormal atrial septal development. Here, we report for the first time, a case-control study investigating the role of MYH3 among non-syndromic ASD patients in contributing to septal development. Four amplicons which will amplifies the 40 kb MYH3 were designed and amplified using long range-PCR. The amplicons were then sequenced using indexed paired-end libraries on the MiSeq platform. The STREGA guidelines were applied for planning and reporting. The non-synonymous c. 3574G>A (p.Ala1192Thr) [p = 0.001, OR = 2.30 (1.36-3.87)] located within the tail domain indicated a highly conserved protein region. The mutant model of c. 3574G>A (p.Ala1192Thr) showed high root mean square deviation (RMSD) values compared to the wild model. To our knowledge, this is the first study to provide compelling evidence on the pathogenesis of MYH3 variants towards ASD hence, suggesting the crucial role of non-synonymous variants in the tail domain of MYH3 towards atrial septal development. It is hoped that this gene can be used as panel for diagnosis of ASD in future.
PURPOSE:
To screen for mutations in the coding region of the myocilin (MYOC) gene in a large Malay family with juvenile-onset open angle glaucoma (JOAG).
METHODS:
A total of 122 family members were thoroughly examined and screened for JOAG. Venipuncture was conducted. Genomic DNA was extracted from peripheral blood leukocytes. The presence of a mutation and a polymorphism was ascertained with PCR amplification followed by the direct sequencing technique.
RESULTS:
Thirty-two of the 122 screened family members were identified to have JOAG (11 new cases and 21 known cases). An autosomal dominant inheritance pattern with incomplete penetrance was observed. A C→A substitution at position 1440 in exon 3 that changes asparagine (AAC) to lysine (AAA) was identified in affected family members except two probands (III:5 and IV:6). Six probands were identified as having the Asn480Lys mutation but have not developed the disease yet. An intronic polymorphism IVS2 730 +35 G>A was also identified. There was a significant association between Asn480Lys (p<0.001) and IVS2 730+35G>A (p<0.001) in the affected and unaffected probands in this family.
CONCLUSIONS:
The Asn480Lys mutation and the IVS2 730+35 G>A polymorphism increased susceptibility to JOAG in this large Malay pedigree. Identifying the MYOC mutations and polymorphisms is important for providing presymptomatic molecular diagnosis.
Lissencephaly (LIS), denoting a "smooth brain," is characterized by the absence of normal cerebral convolutions with abnormalities of cortical thickness. Pathogenic variants in over 20 genes are associated with LIS. The majority of posterior predominant LIS is caused by pathogenic variants in LIS1 (also known as PAFAH1B1), although a significant fraction remains without a known genetic etiology. We now implicate CEP85L as an important cause of posterior predominant LIS, identifying 13 individuals with rare, heterozygous CEP85L variants, including 2 families with autosomal dominant inheritance. We show that CEP85L is a centrosome protein localizing to the pericentriolar material, and knockdown of Cep85l causes a neuronal migration defect in mice. LIS1 also localizes to the centrosome, suggesting that this organelle is key to the mechanism of posterior predominant LIS.
Candidate variant association studies have been largely unsuccessful in identifying common breast cancer susceptibility variants, although most studies have been underpowered to detect associations of a realistic magnitude. We assessed 41 common non-synonymous single-nucleotide polymorphisms (nsSNPs) for which evidence of association with breast cancer risk had been previously reported. Case-control data were combined from 38 studies of white European women (46 450 cases and 42 600 controls) and analyzed using unconditional logistic regression. Strong evidence of association was observed for three nsSNPs: ATXN7-K264R at 3p21 [rs1053338, per allele OR = 1.07, 95% confidence interval (CI) = 1.04-1.10, P = 2.9 × 10(-6)], AKAP9-M463I at 7q21 (rs6964587, OR = 1.05, 95% CI = 1.03-1.07, P = 1.7 × 10(-6)) and NEK10-L513S at 3p24 (rs10510592, OR = 1.10, 95% CI = 1.07-1.12, P = 5.1 × 10(-17)). The first two associations reached genome-wide statistical significance in a combined analysis of available data, including independent data from nine genome-wide association studies (GWASs): for ATXN7-K264R, OR = 1.07 (95% CI = 1.05-1.10, P = 1.0 × 10(-8)); for AKAP9-M463I, OR = 1.05 (95% CI = 1.04-1.07, P = 2.0 × 10(-10)). Further analysis of other common variants in these two regions suggested that intronic SNPs nearby are more strongly associated with disease risk. We have thus identified a novel susceptibility locus at 3p21, and confirmed previous suggestive evidence that rs6964587 at 7q21 is associated with risk. The third locus, rs10510592, is located in an established breast cancer susceptibility region; the association was substantially attenuated after adjustment for the known GWAS hit. Thus, each of the associated nsSNPs is likely to be a marker for another, non-coding, variant causally related to breast cancer risk. Further fine-mapping and functional studies are required to identify the underlying risk-modifying variants and the genes through which they act.
Giardia duodenalis is an important intestinal protozoan in Yemen with infection rates ranging from 18% to 27%. To date, there has been no genotyping study to provide a better understanding of the transmission dynamic. This study was conducted to genotype and subtype G. duodenalis in Yemen. Stool samples were collected from 503 Yemeni outpatients between 1 and 80 years old, including 219 males and 284 females. Giardia cysts were detected via microscopy after the formal-ether concentration. Genotyping of Giardia was carried out using PCR and sequence analysis of the 16s rRNA and b-giardin genes. Of the 89 microscopy-positive Giardia samples, 65 were successfully sequenced, of which 66% (43 of 65) were identified as G. duodenalis assemblage A and 34% (22 of 65) as assemblage B. Further subtyping analysis based on b-giardin gene identified the presence of subtypes A2 and A3, which belong to the anthroponotic sub-assemblage AII. Data of the study suggest that anthroponotic transmission played a potential role in the transmission of giardiasis in the community. However, further genotyping and subtyping studies of specimens from humans and animals living in the same households are needed for a more definitive understanding of giardiasis transmission in Yemen.
Colorectal cancer (CRC) is the third most common malignancy in males and the second most common cancer worldwide. Chronic colonic inflammation is a known risk factor for CRC. Cocoa contains many polyphenolic compounds that have beneficial effects in humans. The objective of this study is to explore the antioxidant properties of cocoa in the mouse model of azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced colitis-associated cancer, focusing on the activation of Nrf2 signaling. Mice were treated with AOM/DSS and randomized to receive either a control diet or a 5 and 10% cocoa diet during the study period. On day 62 of the experiment, the entire colon was processed for biochemical and histopathological examination and further evaluations. Increased levels of malondialdehyde (MDA) were observed in AOM/DSS-induced mice; however, subsequent administration of cocoa decreased the MDA. Enzymatic and nonenzymatic antioxidants, such as superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase, were decreased in the AOM/DSS mice. Cocoa treatment increases the activities/levels of enzymatic and nonenzymatic antioxidants. Inflammatory mediators, such as inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2, were elevated during AOM/DSS-induction, and treatment with 5 and 10% cocoa effectively decreases the expression of iNOS and COX-2. The NF-E2-related factor 2 and its downstream targets, such as NQO1 and UDP-GT, were increased by cocoa treatment. The results of our study suggest that cocoa may merit further clinical investigation as a chemopreventive agent that helps prevent CAC.