ECEL1 novel mutation in arthrogryposis type 5D: A molecular dynamic simulation study.

BACKGROUND: ECEL1 has been presented as a causal gene of an autosomal recessive form distal arthrogryposis (DA) which affects the distal joints. The present study focused on bioinformatic analysis of a novel mutation in ECEL1, c.535A>G (p. Lys179Glu), which was reported in a family with 2 affected boys and fetus through prenatal diagnosis. METHODS: Whole-exome sequencing data analyzed followed by molecular dynamic (MD) simulation of native ECEL1 protein and mutant structures using GROMACS software. One variant c.535A>G, p. Lys179Glu (homozygous) on gene ECEL1 has been detected in proband which was validated in all family members through Sanger sequencing. RESULTS: We demonstrated remarkable constructional differences by MD simulation between wild-type and novel mutant of ECEL1 gene. The reason for the lack of the Zn ion binding in mutation in the ECEL1 protein has been identified by average atomic distance and SMD analysis among the wild-type and mutant. CONCLUSION: Overall, in this study, we present knowledge of the effect of the studied variant on the ECEL1 protein leading to neurodegenerative disorder in humans. This work may hopefully be supplementary to classical molecular dynamics to dissolve the mutational effects of cofactor-dependent protein.

Association of Genetic Polymorphisms in GSTP1, GSTM1, and GSTT1 Genes with Vesicoureteral Reflux Susceptibility in the Children of Southeast Iran.

BACKGROUND: Vesicoureteral reflux (VUR) disease is the most common type of urinary tract anomalies in children. Genetic risk factors may be associated with the etiology of VUR. The role of the Glutathione S-transferases (GSTs) as multifunctional enzymes is cellular oxidative stress handling. This is the first study aimed at evaluating the relative risk of GSTP1, GSTM1, and GSTT1 polymorphisms in VUR susceptibility in children and provides new important insights into the genetics of affected children. METHODS: The study was done in 2013 in Sistan and Baluchestan University, eastern Iran. Genotyping of three GSTP1, GSTM1, and GSTT1 genes were determined using the multiplex polymerase chain reaction assay in 216 reactions for 72 VUR children and 312 reactions for 104 healthy controls. RESULTS: The presence of GSTT1 deletion was associated with high risk of VUR in children, whereas GSTP1 and GSTM1 genotypes did not show the same effect. Furthermore, the combination of GSTT1/GSTM1 and GSTT1/ GSTP1 genotypes showed a significant influence on lower risk of VUR in children. CONCLUSION: Deletion of GSTT1 functional gene is a genetic risk factor causing VUR in children. Interestingly, the combination of GSTM1 and GSTP1 null genotypes with GSTT1 has shown a protective role against risk of GSTT1 deletion.

Hereditary thrombophilia genetic variants in recurrent pregnancy loss.

BACKGROUND: The relationship between thrombophilia genes and recurrent pregnancy loss has been discussed. The aim of this study was to investigate the association between of MTHFR C677T, A1298C, F2G20210A, and F5 G1691A genetic variants among Iranian women with recurrent miscarriage. METHODS: A total of 245 women with two or more recurrent pregnancy loss, with mean age years were enrolled in the study. To compare genotypes, we have selected 250 healthy women without history of miscarriage as control group. Genomic DNA of participants was evaluated using polymerase chain reaction followed by Sanger sequencing to determine the genotype frequency. RESULTS: The mean age were 32.16 ± (21-42) and 31.81 ± (19-40) for case and control groups respectively. MTHFR C677T and A1298C mutant alleles were found to be significantly more prevalent in patients than control. However, F2G20210A and F5 G1691A genetic variants showed no significance. CONCLUSION: The allele frequencies for the assessed genotypes in this study are consistent with the data obtained for other countries. We observed significant susceptible effects of MTHFR C677T, and A1298C among participants. According to the relatively high prevalence of these variants, we recommend genetic testing for women with RPL before therapeutic decisions.

Expanding the clinical phenotype of IARS2-related mitochondrial disease.

BACKGROUND: IARS2 encodes a mitochondrial isoleucyl-tRNA synthetase, a highly conserved nuclear-encoded enzyme required for the charging of tRNAs with their cognate amino acid for translation. Recently, pathogenic IARS2 variants have been identified in a number of patients presenting broad clinical phenotypes with autosomal recessive inheritance. These phenotypes range from Leigh and West syndrome to a new syndrome abbreviated CAGSSS that is characterised by cataracts, growth hormone deficiency, sensory neuropathy, sensorineural hearing loss, and skeletal dysplasia, as well as cataract with no additional anomalies. METHODS: Genomic DNA from Iranian probands from two families with consanguineous parental background and overlapping CAGSSS features were subjected to exome sequencing and bioinformatics analysis. RESULTS: Exome sequencing and data analysis revealed a novel homozygous missense variant (c.2625C > T, p.Pro909Ser, NM_018060.3) within a 14.3 Mb run of homozygosity in proband 1 and a novel homozygous missense variant (c.2282A > G, p.His761Arg) residing in an ~ 8 Mb region of homozygosity in a proband of the second family. Patient-derived fibroblasts from proband 1 showed normal respiratory chain enzyme activity, as well as unchanged oxidative phosphorylation protein subunits and IARS2 levels. Homology modelling of the known and novel amino acid residue substitutions in IARS2 provided insight into the possible consequence of these variants on function and structure of the protein. CONCLUSIONS: This study further expands the phenotypic spectrum of IARS2 pathogenic variants to include two patients (patients 2 and 3) with cataract and skeletal dysplasia and no other features of CAGSSS to the possible presentation of the defects in IARS2. Additionally, this study suggests that adult patients with CAGSSS may manifest central adrenal insufficiency and type II esophageal achalasia and proposes that a variable sensorineural hearing loss onset, proportionate short stature, polyneuropathy, and mild dysmorphic features are possible, as seen in patient 1. Our findings support that even though biallelic IARS2 pathogenic variants can result in a distinctive, clinically recognisable phenotype in humans, it can also show a wide range of clinical presentation from severe pediatric neurological disorders of Leigh and West syndrome to both non-syndromic cataract and cataract accompanied by skeletal dysplasia.