Prenatal diagnosis of citrullinemia type 1; seven families with c.1168G>A mutation of Argininosuccinate synthetase 1 gene in Southwest Iran: A case series

Background: Citrullinemia type 1 is an autosomal recessive disease resulting in ammonia accumulation in the blood, and if uncontrolled may progress to coma or death in the early months after birth. Cases presentation: 7 families from Southwest Iran having one or more children in their families or relatives, who died in the early months after birth due to citrullinemia type 1 visited for genetic counseling and prenatal diagnosis. Whole-exome sequencing was performed on peripheral blood specimens and chorionic villus samples. Sanger sequencing confirmed the genetic results. Both parents were identified as carriers for the exon 15 c.1168G>A mutation in each family. The fetus in 6 out of 7 families was homozygote for A substitution on the argininosuccinate synthetase 1 gene. Conclusion: The presence of a common mutation in the argininosuccinate synthetase 1 gene in all affected families of Southwest Iran shows a possible population cluster in this area. Key words: Argininosuccinate synthetase, Chorionic villus sampling, Point mutation

Dystrophic Epidermolysis Bullosa: COL7A1 Mutation Landscape in a Multi-Ethnic Cohort of 152 Extended Families with High Degree of Customary Consanguineous Marriages

Dystrophic epidermolysis bullosa is a heritable skin disease manifesting with sub-lamina densa blistering, erosions, and chronic ulcers. COL7A1, encoding type VII collagen, has been identified as the candidate gene for dystrophic epidermolysis bullosa. In this study, we have identified COL7A1 mutations in a large multi-ethnic cohort of 152 extended Iranian families with high degree of consanguinity. The patients were diagnosed by clinical manifestations, histopathology, and immunoepitope mapping. Mutation detection consisted of a combination of single nucleotide polymorphism-based whole-genome homozygosity mapping, Sanger sequencing, and gene-targeted next-generation sequencing. A total of 104 distinct mutations in COL7A1 were identified in 149 of 152 families (98%), 56 (53%) of them being previously unreported. Ninety percent of these mutations were homozygous recessive, reflecting consanguinity in these families. Three recurrent mutations were identified in five or more families, and haplotype analysis suggested a founder effect in two of them. In conclusion, COL7A1 harbored mutations in the overwhelming majority of patients with dystrophic epi-dermolysis bullosa, and most of them in this Iranian cohort were consistent with autosomal recessive inheri-tance. The mutation profile attests to the impact of consanguinity in these families

Gene-Targeted Next Generation Sequencing Identifies PNPLA1 Mutations in Patients with a Phenotypic Spectrum of Autosomal Recessive Congenital Ichthyosis: The Impact of Consanguinity

Heritable forms of ichthyoses, also referred to as generalized Mendelian disorders of cornification, are phenotypically a highly heterogeneous group of conditions caused by mutations in a number of genes playing a role in keratinocyte differentiation and epidermal barrier function (Baden and Digiovanna, 2013; Schmuth et al., 2013). These diseases are characterized by scaling and hyperkeratosis with associated cutaneous and extracutaneous features. This group of disorders is also genetically heterogeneous, with autosomal dominant, autosomal recessive, and X-linked inheritance being described. A specific subgroup of inherited ichthyoses is the autosomal recessive congenital ichthyosis (ARCI), with many newborns presenting as collodion babies, but the subsequent clinical presentation and the spectrum of severity can be highly variable (Richard and Bale, 2014). In the most severe forms, such as harlequin ichthyosis, the disease is often fatal during the early postnatal period, whereas at the other end of the continuum of the spectrum, the disease may present with a relatively mild scaling and variable degree of palmoplantar keratoderma. There is considerable genetic heterogeneity in ARCI, and as many as nine different genes are known to harbor biallelic mutations; these include TGM1, ALOXE3, ALOX12B, NIPAL4, ABCA12, CYP4F22, PNPLA1, LIPN, and CERS3. Previous reports have suggested that mutations in TGM1 account for 30e65% of patients with ARCI, whereas mutations in LIPN, PNPLA1, and CERS3 have been reported only in a few consanguineous families (Richard and Bale, 2014). With the advent of next generation sequencing (NGS), there has been tremendous progress in facilitating the mutation detection in various heritable skin disorders, including ichthyosis (South et al., 2015; Takeichi et al., 2013). In fact, at least 38 different genes have now been suggested to be associated with the ichthyotic phenotypes, either as the primary mutated genes or modifying the phenotypic presentation. To elucidate the genetic basis of ichthyosis in Iran, a country of approximately 80 million people with high prevalence of customary consanguineous marriages, we developed a gene-targeted NGS array consisting of 38 genes reported in association with ichthyosis phenotypes. Identification of specific mutations in a large number of families has allowed us to examine phenotype/genotype correlations with respect to both intra- and interfamilial heterogeneity, in part because of extensive consanguinity in these families. In this study, we identified six distinct and, to our knowledge, previously unreported mutations in the PNPLA1 gene in nine families

Recessive mutation in tetraspanin CD151 causes Kindler syndrome-like epidermolysis bullosa with multi-systemic manifestations including nephropathy

Epidermolysis bullosa (EB) is caused by mutations in as many as 19 distinct genes. We have developed a next-generation sequencing (NGS) panel targeting genes known to be mutated in skin fragility disorders, including tetraspanin CD151 expressed in keratinocytes at the dermal-epidermal junction. The NGS panel was applied to a cohort of 92 consanguineous families of unknown subtype of EB. In one family, a homozygous donor splice site mutation in CD151 (NM_139029; c.351 + 2T > C) at the exon 5/intron 5 border was identified, and RT-PCR and whole transcriptome analysis by RNA-seq confirmed deletion of the entire exon 5 encoding 25 amino acids. Immunofluorescence of proband's skin and Western blot of skin proteins with a monoclonal antibody revealed complete absence of CD151. Transmission electron microscopy showed intracellular disruption and cell-cell dysadhesion of keratinocytes in the lower epidermis. Clinical examination of the 33-year old proband, initially diagnosed as Kindler syndrome, revealed widespread blistering, particularly on pretibial areas, poikiloderma, nail dystrophy, loss of teeth, early onset alopecia, and esophageal webbing and strictures. The patient also had history of nephropathy with proteinuria. Collectively, the results suggest that biallelic loss-of-function mutations in CD151 underlie an autosomal recessive mechano-bullous disease with systemic features. Thus, CD151 should be considered as the 20th causative, EB-associated gene

Conjugated linoleic acid: a potent fatty acid linked to animal and human health

Conjugated linoleic acid (CLA) is a mixture of isomers of linoleic acid (C18:2 n-6), which is mostly found in the ruminant meat and dairy products. The CLA is known to have many potential health benefits, and considered a potent powerful fatty acid, which is linked to animal and human health. The present work aims to discuss the source and production, mechanism of action, and effects of CLA on humans, poultry and ruminants by reviewing the recent studies carried out on CLA. Despite most of recent studies indicating beneficial effects of CLA on improving body weight control parameters, its effects on reducing risk factors of cardiovascular diseases (CVD), inflammation, blood glucose and insulin are still controversial, and need to be further studied in different hosts

Replication of TCF7L2 rs7903146 association with type 2 diabetes in an Iranian population

The transcription factor 7-like 2 gene (TCF7L2) rs7903146 T allele is constantly associated with Type 2 diabetes in various populations and ethnic groups. Nevertheless, this has not been observed in two studies involving Arab populations. The aim of the present study was to investigate the association between TCF7L2 rs7903146 in an Iranian population. Type 2 diabetes patients (N = 258) and normal healthy control subjects (N = 168) from the same area, were examined. The ARMS- PCR (Amplification Refractory Mutation System) technique, subsequently validated by direct sequencing, was used for genotyping. Allele and genotype frequencies were significantly different between patients and controls TT vs. CT + CC [p 0.0081 OR 3.4 95%CI (1.27-11.9)] and T vs. C allele [p 0.02 OR 1.4 95%CI (1.03-1.9)]. Our data thus confirm the association between the rs7903146 T allele and T2D in an Iranian population, contrary to previous reports in Arab populations. This can possibly be attributed to differences in ethnic background or the effects of environmental factors