A recurrent homozygous missense DPM3 variant leads to muscle and brain disease.

Biallelic pathogenic variants in the genes encoding the dolichol-phosphate mannose synthase subunits (DPM) which produce mannosyl donors for glycosylphosphatidylinositols, N-glycan and protein O- and C-mannosylation, are rare causes of congenital disorders of glycosylation. Pathogenic variants in DPM1 and DPM2 are associated with muscle-eye-brain (MEB) disease, whereas DPM3 variants have mostly been reported in patients with isolated muscle disease-dystroglycanopathy. Thus far, only one affected individual with compound heterozygous DPM3 variants presenting with myopathy, mild intellectual disability, seizures, and nonspecific white matter abnormalities (WMA) around the lateral ventricles has been described. Here we present five affected individuals from four unrelated families with global developmental delay/intellectual disability ranging from mild to severe, microcephaly, seizures, WMA, muscle weakness and variable cardiomyopathy. Exome sequencing of the probands revealed an ultra-rare homozygous pathogenic missense DPM3 variant NM_018973.4:c.221A>G, p.(Tyr74Cys) which segregated with the phenotype in all families. Haplotype analysis indicated that the variant arose independently in three families. Functional analysis did not reveal any alteration in the N-glycosylation pathway caused by the variant; however, this does not exclude its pathogenicity in the function of the DPM complex and related cellular pathways. This report provides supporting evidence that, besides DPM1 and DPM2, defects in DPM3 can also lead to a muscle and brain phenotype

Altered expression of the suppressors PML and p53 in glioblastoma cells with the antisense-EGF-receptor

Gene amplification and enhanced expression of the epidermal growth factor receptor (EGFR) represent the major molecular genetic alteration in glioblastomas and it may play an essential role in cell growth and in the carcinogenic process. On the other hand, the nuclear suppressor proteins PML and p53 are also known to play critical roles in cancer development and in suppressing cell growth. Here we report that, in glioblastoma cells with defective EGFR function, the expressions of both promyelocytic leukaemia (PML) and p53 were altered. Cells that were transfected with the antisense-cDNA of EGFR were found to have more cells in G1 and fewer cells in S phase. In addition, the transfected cells were found to be non-responsive to EGF-induced cell growth. Interestingly, the expression of the suppressors p53 and PML were found to be significantly increased by immunohistochemical assay in the antisense-EGFR cells. Moreover, the PML expression in many of the cells was converted from the nuclear dot pattern into fine-granulated staining pattern. In contrast, the expressions of other cell cycle regulated genes and proto-oncogene, including the cyclin-dependent kinase 4 (cdk4), retinoblastoma, p16INK4a and p21H-ras, were not altered. These data indicate that there are specific inductions of PML and p53 proteins which may account for the increase in G1 and growth arrest in antisense-EGFR treated cells. It also indicates that the EGF, p53 and PML transduction pathways were linked and they may constitute an integral part of an altered growth regulatory programme. The interactions and cross-talks of these critical molecules may be very important in regulating cell growth, differentiation and cellular response to treatment in glioblastomas. © 1999 Cancer Research Campaig

Phenylketonuria in Portugal: Genotype-Phenotype Correlations Using Molecular, Biochemical, and Haplotypic Analyses

The impairment of the hepatic enzyme phenylalanine hydroxylase (PAH) causes elevation of phenylalanine levels in blood and other body fluids resulting in the most common inborn error of amino acid metabolism (phenylketonuria). Persistently high levels of phenylalanine lead to irreversible damage to the nervous system. Therefore, early diagnosis of the affected individuals is important, as it can prevent clinical manifestations of the disease.info:eu-repo/semantics/publishedVersio

Loss of the Promyelocytic Leukemia Protein in Gastric Cancer: Implications for IP-10 Expression and Tumor-Infiltrating Lymphocytes

Gastric cancer is one of the most common causes of cancer-related mortality worldwide. Expression of the tumor suppressor, promyelocytic leukemia (PML) protein, is reduced or abolished in gastric carcinomas, in association with an increased level of lymphatic invasion, development of higher pTNM staging, and unfavorable prognosis. Herein, we investigated the relationship between the extent of tumor-infiltrating lymphocytes and the status of PML protein expression in advanced gastric carcinoma. We observed higher numbers of infiltrating T-cells in gastric carcinoma tissues in which PML expression was reduced or abolished, compared to tissues positive for PML. The extent of T-cell migration toward culture supernatants obtained from interferon-gamma (IFN-γ-stimulated gastric carcinoma cell lines was additionally affected by expression of PML in vitro. Interferon-gamma-inducible protein 10 (IP-10/CXCL10) expression was increased in gastric carcinoma tissues displaying reduced PML levels. Moreover, both Pml knockout and knockdown cells displayed enhanced IP-10 mRNA and protein expression in the presence of IFN-γ. PML knockdown increased IFN-γ-mediated Signal Transducer and Activator of Transcription-1 (STAT-1) binding to the IP-10 promoter, resulting in elevated transcription of the IP-10 gene. Conversely, PML IV protein expression suppressed IP-10 promoter activation. Based on these results, we propose that loss of PML protein expression in gastric cancer cells contributes to increased IP-10 transcription via enhancement of STAT-1 activity, which, in turn, promotes lymphocyte trafficking within tumor regions

SCUBE3 loss-of-function causes a recognizable recessive developmental disorder due to defective bone morphogenetic protein signaling

Signal peptide-CUB-EGF domain-containing protein 3 (SCUBE3) is a member of a small family of multifunctional cell surface-anchored glycoproteins functioning as co-receptors for a variety of growth factors. Here we report that bi-allelic inactivating variants in SCUBE3 have pleiotropic consequences on development and cause a previously unrecognized syndromic disorder. Eighteen affected individuals from nine unrelated families showed a consistent phenotype characterized by reduced growth, skeletal features, distinctive craniofacial appearance, and dental anomalies. In vitro functional validation studies demonstrated a variable impact of disease-causing variants on transcript processing, protein secretion and function, and their dysregulating effect on bone morphogenetic protein (BMP) signaling. We show that SCUBE3 acts as a BMP2/BMP4 co-receptor, recruits the BMP receptor complexes into raft microdomains, and positively modulates signaling possibly by augmenting the specific interactions between BMPs and BMP type I receptors. Scube3(-/-) mice showed craniofacial and dental defects, reduced body size, and defective endochondral bone growth due to impaired BMP-mediated chondrogenesis and osteogenesis, recapitulating the human disorder. Our findings identify a human disease caused by defective function of a member of the SCUBE family, and link SCUBE3 to processes controlling growth, morphogenesis, and bone and teeth development through modulation of BMP signaling.Genetics of disease, diagnosis and treatmen

Characterisation of transcriptional regulatory function of human acute promyelocytic leukaemia proteins, PML and PMLRAR#alpha#

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN013565 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

The Investigation of Haplotype Phasing Efficiency at the PAH Gene Region in Iranian Family Trios

"nBackground: The haplotype phasing is more useful than genotyping markers independently at carrier detection and prena­tal diagnosis of diseases. The PAH gene region contains several markers used in detection of PKU disease. In the present study, the efficiency of BglII-EcoRI-VNTR haplotype phasing in Iranian family trios was investigated. Then, this informa­tion was compared with those obtained for unrelated individuals."nMethods: Blood samples were collected from 20 healthy family trios and 60 unrelated individuals. The genomic DNA was ex­tracted by use of salting-out procedure. The two markers BglII and EcoRI were genotyped by use of PCR-RFLP. The geno­type of VNTR marker was identified by use of PCR and electrophoresis. The genotyping data obtained from family trios was used to infer haplotype phase. We also compared this data with results obtained from a widely used method for hap­lotype frequency inference from unrelated individuals, the PHASE program."nResults: The haplotype phase of all members was only ascertained at eight family trios.  The comparison of this data with the results obtained by use of PHASE program showed that eight haplotypes [211, 221, 215, 216, 214, 121, 225 and 111] were in­formative haplotypes in Iranian population."nConclusion: Since diversity of BglII-EcoRI-VNTR haplotypes was high in Iranian population, haplotype phasing at family trios was difficult. The results of this study showed that the genotyping data obtained from family trios could not provide enough information for BglII-EcoRI-VNTR haplotype phasing at Iranian PKU families and the genotyping of other family mem­bers was necessary at most cases

Genotyping Rs2274625 Marker in NPHS2 Gene Associated with Nephrotic Syndrome in Isfahan Population

Introduction: Nephrotic syndrome (NS) is a genetic disease belonging to a heterogeneous group of glomerular disorders, which mainly occurs within the children. Linkage analysis using single nucleotide polymorphisms (SNP) is used as an indirect method in molecular diagnosis of the disease. A large number of SNP markers have been introduced in NPHS2gene in the available electronic databases. Method: In the present study, the genotype and informative status of rs2274625 marker in NPHS2 genewas investigated in 120 unrelated healthy individuals using Tetra-primer ARMS PCR technique and newly designed primers. Allelic frequency and presence of Hardy Weinberg Equilibrium (HWE) was estimated using GenePop website. Furthermore, PowerMarker software was utilized in order to compute the index of polymorphism information content (PIC). Results: The study results indicated allele frequency of 97% and 3% for C and T alleles, respectively, in regard with rs2274625 marker within Isfahan population. Moreover, the PIC for the rs2274625 marker was 0.5%, and HWE revealed the equilibruim of the study population in regard with the related marker. Conclusion: As the study findings indicated, rs2274625 could be introduced as an SNP marker in the linkage analysis in order to molecularly trace NPHS2 gene mutations in molecular NS diagnosis in Isfahan population as a representative sample of the Iranian population