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1.
Int J Biol Macromol ; 250: 126278, 2023 Oct 01.
Article in English | MEDLINE | ID: mdl-37572818

ABSTRACT

This study aimed to investigate whether the gastroprotective effects of three types of bacterial levans are correlated with their prebiotic-associated anti-inflammatory/antioxidant potentials. Three levans designated as LevAE, LevP, and LevZ were prepared from bacterial honey isolates; purified, and characterized using TLC, NMR, and FTIR. The anti-inflammatory properties of levan preparations were assessed in LPS-stimulated RAW 264.7 cell lines, while their safety and gastroprotective potentials were assessed in Wistar rats. The three levans significantly reduced ulcer number (22.29-70.05 %) and severity (31.76-80.54 %) in the ethanol-induced gastric ulcer model compared to the control (P < 0.0001/each), with the highest effect observed in LevAE and levZ (200 mg/each) (P < 0.0001). LevZ produced the highest levels of glutathione; catalase activity, and the lowest MDA levels (P = 0.0001/each). The highest anti-inflammatory activity was observed in LevAE and levZ in terms of higher inhibitory effect on IL-1ß and TNF-α production (P < 0.0001 each); COX2, PGE2, and NF-κB gene expression. The three levan preparations also proved safe with no signs of toxicity, with anti-lipidemic properties as well as promising prebiotic activity that directly correlated with their antiulcer effect. This novel study highlights the implication of prebiotic-mediated systemic immunomodulation exhibited by bacterial levans that directly correlated with their gastroprotective activity.

2.
Clin Genet ; 104(1): 121-126, 2023 07.
Article in English | MEDLINE | ID: mdl-36896672

ABSTRACT

PKDCC encodes a component of Hedgehog signalling required for normal chondrogenesis and skeletal development. Although biallelic PKDCC variants have been implicated in rhizomelic shortening of limbs with variable dysmorphic features, this association was based on just two patients. In this study, data from the 100 000 Genomes Project was used in conjunction with exome sequencing and panel-testing results accessed via international collaboration to assemble a cohort of eight individuals from seven independent families with biallelic PKDCC variants. The allelic series included six frameshifts, a previously described splice-donor site variant and a likely pathogenic missense variant observed in two families that was supported by in silico structural modelling. Database queries suggested that the prevalence of this condition is between 1 of 127 and 1 of 721 in clinical cohorts with skeletal dysplasia of unknown aetiology. Clinical assessments, combined with data from previously published cases, indicate a predominantly upper limb involvement. Micrognathia, hypertelorism and hearing loss appear to be commonly co-occurring features. In conclusion, this study strengthens the link between biallelic inactivation of PKDCC and rhizomelic limb-shortening and will enable clinical testing laboratories to better interpret variants in this gene.


Subject(s)
Dwarfism , Osteochondrodysplasias , Humans , Hedgehog Proteins , Osteochondrodysplasias/pathology , Prevalence , RNA Splice Sites
3.
J Inherit Metab Dis ; 44(4): 987-1000, 2021 07.
Article in English | MEDLINE | ID: mdl-33583022

ABSTRACT

Congenital disorders of glycosylation (CDGs) are a continuously expanding group of monogenic disorders of glycoprotein and glycolipid biosynthesis that cause multisystem diseases. Individuals with ALG3-CDG frequently exhibit severe neurological involvement (epilepsy, microcephaly, and hypotonia), ocular anomalies, dysmorphic features, skeletal anomalies, and feeding difficulties. We present 10 unreported individuals diagnosed with ALG3-CDG based on molecular and biochemical testing with 11 novel variants in ALG3, bringing the total to 40 reported individuals. In addition to the typical multisystem disease seen in ALG3-CDG, we expand the symptomatology of ALG3-CDG to now include endocrine abnormalities, neural tube defects, mild aortic root dilatation, immunodeficiency, and renal anomalies. N-glycan analyses of these individuals showed combined deficiencies of hybrid glycans and glycan extension beyond Man5 GlcNAc2 consistent with their truncated lipid-linked precursor oligosaccharides. This spectrum of N-glycan changes is unique to ALG3-CDG. These expanded features of ALG3-CDG facilitate diagnosis and suggest that optimal management should include baseline endocrine, renal, cardiac, and immunological evaluation at the time of diagnosis and with ongoing monitoring.


Subject(s)
Congenital Disorders of Glycosylation/genetics , Mannosyltransferases/genetics , Adolescent , Adult , Child, Preschool , Congenital Disorders of Glycosylation/pathology , Congenital Disorders of Glycosylation/physiopathology , Female , Genotype , Humans , Infant , Infant, Newborn , Male , Phenotype , Young Adult
4.
N Engl J Med ; 382(12): 1166-1174, 2020 03 19.
Article in English | MEDLINE | ID: mdl-32187475
5.
Am J Med Genet B Neuropsychiatr Genet ; 183(3): 172-180, 2020 04.
Article in English | MEDLINE | ID: mdl-31854501

ABSTRACT

Hearing loss (HL) is the most common sensory disorder worldwide and genetic factors contribute to approximately half of congenital HL cases. HL is subject to extensive genetic heterogeneity, rendering molecular diagnosis difficult. Mutations of the transmembrane channel-like 1 (TMC1) gene cause hearing defects in humans and mice. The precise function of TMC1 protein in the inner ear is unknown, although it is predicted to be involved in functional maturation of cochlear hair cells. TMC1 mutations result in autosomal recessive (DFNB7/11) and sometimes dominant (DFNA36) nonsyndromic HL. Mutations in TMC1 are responsible for a significant portion of HL, particularly in consanguineous populations. To evaluate the importance of TMC1 mutations in the Saudi population, we used a combination of autozygome-guided candidate gene mutation analysis and targeted next generation sequencing in 366 families with HL previously shown to lack mutations in GJB2. We identified 12 families that carried five causative TMC1 mutations; including three novel (c.362+3A > G; c.758C > T [p.Ser253Phe]; c.1396_1398delACC [p.Asn466del]) and two reported mutations (c.100C > T [p.Arg34Ter]; c.1714G > A [p.Asp572Asn]). Each of the identified recessive mutation was classified as severe, by both age of onset and severity of HL. Similarly, consistent with the previously reported dominant variant p.Asp572Asn, the HL phenotype was progressive. Eight families in our cohort were found to share the pathogenic p.Arg34Ter mutation and linkage disequilibrium was observed between p.Arg34Ter and SNPs investigated. Our results indicate that TMC1 mutations account for about 3.3% (12/366) of Saudi HL cases and that the recurrent TMC1 mutation p.Arg34Ter is likely to be a founder mutation.


Subject(s)
Hearing Loss, Sensorineural/genetics , Membrane Proteins/genetics , Mutation , Adolescent , Adult , Age of Onset , Child , Child, Preschool , DNA Mutational Analysis , Ear, Inner/metabolism , Exons , Family Health , Female , Genetic Linkage , Genome-Wide Association Study , Genotype , Haplotypes , Humans , Linkage Disequilibrium , Male , Pedigree , Phenotype , Polymorphism, Single Nucleotide , Saudi Arabia , Young Adult
6.
Am J Hum Genet ; 105(6): 1126-1147, 2019 12 05.
Article in English | MEDLINE | ID: mdl-31735293

ABSTRACT

The redox state of the neural progenitors regulates physiological processes such as neuronal differentiation and dendritic and axonal growth. The relevance of endoplasmic reticulum (ER)-associated oxidoreductases in these processes is largely unexplored. We describe a severe neurological disorder caused by bi-allelic loss-of-function variants in thioredoxin (TRX)-related transmembrane-2 (TMX2); these variants were detected by exome sequencing in 14 affected individuals from ten unrelated families presenting with congenital microcephaly, cortical polymicrogyria, and other migration disorders. TMX2 encodes one of the five TMX proteins of the protein disulfide isomerase family, hitherto not linked to human developmental brain disease. Our mechanistic studies on protein function show that TMX2 localizes to the ER mitochondria-associated membranes (MAMs), is involved in posttranslational modification and protein folding, and undergoes physical interaction with the MAM-associated and ER folding chaperone calnexin and ER calcium pump SERCA2. These interactions are functionally relevant because TMX2-deficient fibroblasts show decreased mitochondrial respiratory reserve capacity and compensatory increased glycolytic activity. Intriguingly, under basal conditions TMX2 occurs in both reduced and oxidized monomeric form, while it forms a stable dimer under treatment with hydrogen peroxide, recently recognized as a signaling molecule in neural morphogenesis and axonal pathfinding. Exogenous expression of the pathogenic TMX2 variants or of variants with an in vitro mutagenized TRX domain induces a constitutive TMX2 polymerization, mimicking an increased oxidative state. Altogether these data uncover TMX2 as a sensor in the MAM-regulated redox signaling pathway and identify it as a key adaptive regulator of neuronal proliferation, migration, and organization in the developing brain.


Subject(s)
Brain Diseases/pathology , Brain/abnormalities , Developmental Disabilities/pathology , Membrane Proteins/metabolism , Mitochondria/metabolism , Thioredoxins/metabolism , Adolescent , Adult , Brain Diseases/genetics , Brain Diseases/metabolism , Child , Child, Preschool , Cohort Studies , Developmental Disabilities/genetics , Developmental Disabilities/metabolism , Female , Fibroblasts/metabolism , Fibroblasts/pathology , Follow-Up Studies , Humans , Infant , Infant, Newborn , Male , Membrane Proteins/genetics , Mitochondria/pathology , Oxidation-Reduction , Prognosis , Skin/metabolism , Skin/pathology , Thioredoxins/genetics , Transcriptome
7.
Microb Pathog ; 135: 103626, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31325573

ABSTRACT

Plaque-related diseases are amongst the most common ailments of the oral cavity. Streptococcus mutans is the causal agent of dental caries in animals and humans and is responsible for the formation and accumulation of plaques. This study aimed to identify and evaluate the role of the dental plaque isolates and its surrounding environment in plaque formation or inhibition. The study started with the identification of human dental plaque isolates from high caries index patients based on 16S rRNA and Mitis salivarius bacitracin agar (MSB) was used for S. mutans growing. Unexpectedly, the Streptococcus mutans was completely absent. The disc diffusion assay recorded that all the isolates had antimicrobial activity against the S. mutans growth. Enzymes assay revealed that the isolates produced dextransucrase, levansucrase and levanase activity with wide variation degrees. Also, the lactic acid production assay was done based in pH shift assessment. The highest pH shift and dextran yield were detected by the isolates Bacillus subtilis_AG1 and Bacillus mojavensis_AG3. The adherence test revealed that Lysinibacillus cresolivorans_W2 (MK411028) recorded the highest adhesion property (60%). Oligo- and polysaccharides were synthesized by the action of dextransucrase enzyme and their cytotoxicity tests were negative. Dextran with a molecular weight (117521 Da) recorded the highest antimicrobial efficacy against Bacillus subtilis_AG1 and Bacillusmojavensis_AG3 (65%, 63.5%) respectively. The results concluded that the dextran was the most important factor causing the dental plaque pathogenicity. Also, oral oligo- and polysaccharides might play a role in dental plaque control.


Subject(s)
Bacteria/classification , Bacteria/isolation & purification , Dental Plaque/microbiology , Streptococcus mutans/isolation & purification , Animals , Anti-Bacterial Agents/pharmacology , Bacillaceae/isolation & purification , Bacillus/isolation & purification , Bacillus subtilis/isolation & purification , Bacteria/drug effects , Bacteria/genetics , Bacterial Adhesion , Cell Line , Dental Caries/microbiology , Dextrans/metabolism , Glucosyltransferases , Hexosyltransferases , Humans , Hydrogen-Ion Concentration , Lactic Acid/metabolism , Microbial Sensitivity Tests , Mouth/microbiology , Phylogeny , RNA, Ribosomal, 16S/genetics , Streptococcus mutans/drug effects
8.
BMC Med Genet ; 20(1): 119, 2019 07 04.
Article in English | MEDLINE | ID: mdl-31272422

ABSTRACT

BACKGROUND: Mutations in ARL6IP1, which encodes a tetraspan membrane protein localized to the endoplasmic reticulum (ER), have been recently described in a large family with a complicated form of hereditary spastic paraplegia (HSP). CASE PRESENTATION: We sought to expand the HSP phenotype associated with ARL6IP1 variants by examining a Saudi kindred with a clinically more severe presentation, which resulted in spontaneous neonatal death of both affected siblings. Clinical features encompassed not only spastic paraplegia but also developmental delay, microcephaly, cerebral atrophy, periventricular leukoencephalopathy, hypotonia, seizures, spasticity, jejunal stricture, gastrointestinal reflux, neuropathy, dysmorphism and respiratory distress. We performed clinical assessment and radiological studies of this family, in addition to homozygosity mapping and whole exome sequencing (WES) to identify the disease-associated variant. Homozygosity mapping localized the causative gene to a region on chromosome 16 harboring ARL6IP1. WES of the index case identified the homoallelic nonsense variant, c.112C > T in ARL6IP1 that segregated with the phenotype and was predicted to result in loss of the protein. Allelic expression analysis of the parents demonstrated downward pressure on the mutant allele, suggestive of nonsense-mediated decay. CONCLUSIONS: Our report shows that the phenotype associated with ARL6IP1 variants may be broader and more acute than so far reported and identifies fatal HSP as the severe end of the phenotypic spectrum of ARL6IP1 variants.


Subject(s)
Adaptor Proteins, Signal Transducing/genetics , Genetic Association Studies , Genetic Predisposition to Disease/genetics , Genetic Variation , Membrane Proteins/genetics , Mutation , Spastic Paraplegia, Hereditary/genetics , Alleles , Child, Preschool , Endoplasmic Reticulum/metabolism , Female , Gene Expression Regulation , Homozygote , Humans , Male , Mutation/genetics , Pedigree , Phenotype , Saudi Arabia , Spastic Paraplegia, Hereditary/diagnostic imaging , Spastic Paraplegia, Hereditary/physiopathology , Exome Sequencing
9.
Seizure ; 69: 154-172, 2019 Jul.
Article in English | MEDLINE | ID: mdl-31054490

ABSTRACT

PURPOSE: Epileptic encephalopathies (EE), are a group of age-related disorders characterized by intractable seizures and electroencephalogram (EEG) abnormalities that may result in cognitive and motor delay. Early infantile epileptic encephalopathies (EIEE) manifest in the first year of life. EIEE are highly heterogeneous genetically but a genetic etiology is only identified in half of the cases, typically in the form of de novo dominant mutations. METHOD: This is a descriptive retrospective study of a consecutive series of patients diagnosed with EIEE from the participating hospitals. A chart review was performed for all patients. The diagnosis of epileptic encephalopathy was confirmed by molecular investigations in commercial labs. In silico study was done for all novel mutations. A systematic search was done for all the types of EIEE and their correlated genes in the literature using the Online Mendelian Inheritance In Man and PubMed databases. RESULTS: In this case series, we report 72 molecularly characterized EIEE from a highly consanguineous population, and review their clinical course. We identified 50 variants, 26 of which are novel, causing 26 different types of EIEE. Unlike outbred populations, autosomal recessive EIEE accounted for half the cases. The phenotypes ranged from self-limiting and drug-responsive to severe refractory seizures or even death. CONCLUSIONS: We reported the largest EIEE case series in the region with confirmed molecular testing and detailed clinical phenotyping. The number autosomal recessive predominance could be explained by the society's high consanguinity. We reviewed all the EIEE registered causative genes in the literature and proposed a functional classification.


Subject(s)
Consanguinity , Mutation , Spasms, Infantile/epidemiology , Spasms, Infantile/genetics , Adolescent , Child , Child, Preschool , Female , Genes, Recessive , Humans , Infant , Male , Phenotype , Retrospective Studies , Spasms, Infantile/classification , Young Adult
10.
Pak J Biol Sci ; 21(3): 110-118, 2018.
Article in English | MEDLINE | ID: mdl-30187720

ABSTRACT

BACKGROUND AND OBJECTIVE: Feather wastes are the most abundant keratinous material in the nature and its accumulation causes multiple environmental problems. Nutritive value upgrading of such wastes through biological treatments may provide ruminant's rations with high quality and cost effective source of protein. Therefore, the main objective of this study was to investigate the potential uses of biologically treated feathers (BTF) as a feedstuff for ruminants through in vitro experiments. MATERIALS AND METHODS: Keratinase production time course was performed by ten microbial isolates (3 fungal, 3 actinomyces and 4 bacterial isolates) under static and shaking conditions using turkey feather- synthetic medium. The chemical composition and amino acid analysis for the crude feathers, BTF and soybean meal were determined according to AOAC methods. Two in vitro experiments were conducted to study the effects of crude feathers, BTF and modified ruminant rations (in which soybean meal were substituted by the BTF in 10, 20 and 30%) on rumen fermentation characteristics. Ration's Dry Matter (DM), Organic Matter (OM), Neutral detergent fibre (NDF) and Acid detergent Fibre (ADF) degradability by rumen microorganisms were tested using batch culture technique. Ruminal final pH, ammonia-nitrogen, total volatile fatty acids and short chain fatty acids concentrations were determined after 24 h of incubation. The total gas production volume was determined using 100 mL glass syringes. RESULTS: Bacillus licheniformis ALW1 was the most potent keratinase producer strain under static condition at 37°C for four days of incubation. Feather biological treatment by Bacillus licheniformis increased its content of some of essential-sulphur amino acids. The degradability of BTF by rumen microorganisms was 4 folds higher than crude feather degradability. There were no significant differences between control and partially substituted (R10 and R20) rations in all of rumen fermentation characteristics. CONCLUSION: The utilization of BTF as substitute for costly soybean meal in ruminant's rations up to 20% had no negative effect on all rumen fermentation characteristics.


Subject(s)
Feathers/chemistry , Fermentation/drug effects , Glycine max/chemistry , Rumen/drug effects , Amino Acids/metabolism , Animal Feed , Animals , Bacillus licheniformis/metabolism , Dietary Fiber/metabolism , Dietary Proteins/metabolism , Digestion/drug effects , Fabaceae/chemistry , Fatty Acids, Volatile/metabolism , Nutritive Value/drug effects , Rumen/metabolism , Rumen/microbiology
11.
Carbohydr Polym ; 193: 137-143, 2018 Aug 01.
Article in English | MEDLINE | ID: mdl-29773365

ABSTRACT

A novel synbiotic multiparticulate microparticle was produced in the current study to expand the synbiotic industrial applications. Initially, the inulin was fabricated into PLGA nanoparticles. After the inulin entrapment efficiency was boosted to reach 92.9 ±â€¯8.4% by adjusting the formulation parameters, the developed particles were characterized by different techniques such as particle size analyzer, TEM, and TLC. The obtained data showed that the particle size was 115.8 ±â€¯82.7 nm, the particles had smooth surface and round shape, and the fabrication procedure did not affect the integrity of the inulin. Later, the inulin loaded nanoparticles together with selected Bifidobacterium species were double coated with gum arabic and alginate. The maximum survivability of the encapsulated Bifidobacterium in the simulated gastric solution reached 88.29% of the initial population, which was significantly higher than the survivability of the free bacteria. Finally, the inulin release from the multiparticulate microparticles was studied and found to be sustained over three days.


Subject(s)
Bifidobacterium/isolation & purification , Gastrointestinal Tract/chemistry , Inulin/chemistry , Synbiotics , Capsules/chemistry , Gastrointestinal Tract/microbiology , Particle Size , Surface Properties
12.
Int J Biol Macromol ; 116: 801-810, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29746969

ABSTRACT

A thermostable metallo-collagenase enzyme (150 kDa), recently identified in a newly isolated actinomycestes strain (Nocardiopsis dassonvillei NRC2aza), has been purified from natural source, characterized to have application in wound healing. A simple 3 step purification procedure gave an increase of purity by 6.23 fold with a specific activity of 387.2 U mg-1. The enzyme activity showed stability across a range of pH (7.0-8.5) and temperature (40-55 °C) with optima at pH 8.0 and 60 °C, respectively. Activators include Mg+2, Ca+2, Zn+2, Na+, K+ and Ba+2, while Mn+2, Co+2, Ni+2and Ag+ ions gave partial inhibition. Full inhibition was given by other tested ions and metalloproteinase inhibitors. Broad substrate specificity was demonstrated including activity against a native collagen. The Km and Vmax of the enzyme using azocollagen were 5.5 mg/ml and 1280 U, respectively. The purified collagenase enhanced wound closure in vitro and in vivo and the repair process was dose dependent. Topical application of the purified collagenase (either of 25 or 50 U) to cutaneous wounds significantly accelerated the rate of wound healing and the formation of granulation tissue. Hence, the purified collagenase has a great potential as a therapeutic agent in wound care and collagen related diseases.


Subject(s)
Actinobacteria/enzymology , Bacterial Proteins , Collagenases , Fibroblasts/metabolism , Wound Healing/drug effects , Wounds and Injuries/drug therapy , Animals , Bacterial Proteins/chemistry , Bacterial Proteins/isolation & purification , Bacterial Proteins/pharmacology , Cells, Cultured , Collagenases/chemistry , Collagenases/isolation & purification , Collagenases/pharmacology , Fibroblasts/pathology , Humans , Rats , Rats, Wistar , Wounds and Injuries/metabolism , Wounds and Injuries/pathology
13.
Neurosciences (Riyadh) ; 23(2): 162-164, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29664460

ABSTRACT

Ataxia-Telangiectasia (A-T) is an autosomal recessive disorder caused by variants in ATM gene and characterized by progressive neurologic impairment, cerebellar ataxia, and oculo-cutaneous telangiectasia. Immunodeficiency with a recurrent sinopulmonary infections are observed in patients with A-T. Here, we report a novel stop codon variant, c.5944 C>T (p.Gln1982*), revealed by whole-exome sequencing in a 9-year old boy. He presented with recurrent upper respiratory tract infections, failure to thrive, developmental delay, ataxic gait, and bulbar telangiectasia.


Subject(s)
Ataxia Telangiectasia Mutated Proteins/genetics , Ataxia Telangiectasia/genetics , Codon, Nonsense , Adult , Ataxia Telangiectasia/pathology , Humans , Male , Exome Sequencing
14.
Child Neurol Open ; 5: 2329048X17752237, 2018.
Article in English | MEDLINE | ID: mdl-29372174

ABSTRACT

PRUNE syndrome, or neurodevelopmental disorder with microcephaly, hypotonia, and variable brain anomalies (OMIM#617481), is a new rare autosomal recessive neurodevelopmental disease that is caused by homozygous or compound heterozygous mutation in PRUNE1 on chromosome 1q21. Here, We report on 12-month-old and 30-month-old girls from 2 unrelated Saudi families with typical presentations of PRUNE syndrome. Both patients had severe developmental delay, progressive microcephaly, and dysmorphic features. Brain magnetic resonance imaging showed slight thinning in the corpus callosum, mild frontal brain atrophy, and delayed myelination in one of the patients. Both patients had the same missense mutation in PRUNE1 (c.383G>A, p.Arg128Gln), which was not reported before in a homozygous state. We compared our patients to previously reported cases. In conclusion, We suggest that clinicians consider PRUNE syndrome in any child presenting with dysmorphic features, developmental delay, progressive microcephaly, central hypotonia, peripheral spasticity, delayed myelination, brain atrophy, and a thin corpus callosum.

15.
J Genet Eng Biotechnol ; 16(2): 311-318, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30733740

ABSTRACT

Keratinase are proteolytic enzymes which have gained much attention to convert keratinous wastes that cause huge environmental pollution problems. Ten microbial isolates were screened for their keratinase production. The most potent isolate produce 25.2 U/ml under static condition and was primarily identified by partial 16s rRNA gene sequence as Bacillus licheniformis ALW1. Optimization studies for the fermentation conditions increased the keratinase biosynthesis to 72.2 U/ml (2.9-fold). The crude extracellular keratinase was optimally active at pH 8.0 and temperature 65 °C with 0.7% soluble keratin as substrate. The produced B. licheniformis ALW1 keratinase exhibited a good stability over pH range from 7 to 9 and over a temperature range 50-60 °C for almost 90 min. The crude enzyme solution was able to degrade native feather up to 63% in redox free system.

16.
Heart Rhythm ; 14(8): 1191-1199, 2017 08.
Article in English | MEDLINE | ID: mdl-28438721

ABSTRACT

BACKGROUND: Congenital long QT syndrome (LQTS) is an inherited, potentially fatal arrhythmogenic disorder. At least 16 genes have been implicated in LQTS; the yield of genetic analysis of 3 genes (KCNQ1, KCNH2, and SCN5A) is about 70%, with KCNQ1 mutations accounting for ∼50% of positive cases. LQTS is mostly inherited in an autosomal dominant pattern. Systemic analysis of LQTS has not been previously conducted in a population with a high degree of consanguinity. OBJECTIVES: To describe the clinical and molecular profiles of LQTS in the highly consanguineous Saudi population. METHODS: Fifty-six Saudi families with LQTS were consecutively recruited and evaluated. Sequencing of KCNQ1, KCNH2, and SCN5A genes was conducted on all probands, followed by screening of family relatives. RESULTS: Genetic analysis was positive in 32 (57.2%) families, with mutations in KCNQ1 identified in 28 families (50%). Surprisingly, 17 (53.1%) probands were segregating homozygous mutations. Family screening identified 123 individuals with mutations; 89 (72.4%) were heterozygous, 23 (18.7%) were homozygous, and 11 (8.9%) were compound heterozygous. Compared to heterozygous, the phenotype was more severe in homozygous individuals, with cardiac symptoms in 78.3% (vs 12.4%), family history of sudden death in 64.7% (vs 44.4%), and prolonged QT interval in 100% (vs 43.8%). Congenital deafness was found in 11 (47.8%) homozygous probands. CONCLUSION: Our study provides insight into the clinical and molecular profiles of LQTS in a consanguineous population. It underscores the importance of preemptive management in homozygous patients with LQTS and the value of clinical and molecular screening of at-risk relatives.


Subject(s)
Consanguinity , Genetic Testing/methods , Long QT Syndrome/genetics , Adolescent , Adult , Child , Child, Preschool , Female , Follow-Up Studies , Genotype , Heterozygote , Homozygote , Humans , Incidence , Infant , Infant, Newborn , Long QT Syndrome/epidemiology , Male , Middle Aged , Pedigree , Phenotype , Retrospective Studies , Saudi Arabia/epidemiology , Survival Rate/trends , Young Adult
17.
Genome Biol ; 17(1): 242, 2016 11 28.
Article in English | MEDLINE | ID: mdl-27894351

ABSTRACT

BACKGROUND: Ciliopathies are clinically diverse disorders of the primary cilium. Remarkable progress has been made in understanding the molecular basis of these genetically heterogeneous conditions; however, our knowledge of their morbid genome, pleiotropy, and variable expressivity remains incomplete. RESULTS: We applied genomic approaches on a large patient cohort of 371 affected individuals from 265 families, with phenotypes that span the entire ciliopathy spectrum. Likely causal mutations in previously described ciliopathy genes were identified in 85% (225/265) of the families, adding 32 novel alleles. Consistent with a fully penetrant model for these genes, we found no significant difference in their "mutation load" beyond the causal variants between our ciliopathy cohort and a control non-ciliopathy cohort. Genomic analysis of our cohort further identified mutations in a novel morbid gene TXNDC15, encoding a thiol isomerase, based on independent loss of function mutations in individuals with a consistent ciliopathy phenotype (Meckel-Gruber syndrome) and a functional effect of its deficiency on ciliary signaling. Our study also highlighted seven novel candidate genes (TRAPPC3, EXOC3L2, FAM98C, C17orf61, LRRCC1, NEK4, and CELSR2) some of which have established links to ciliogenesis. Finally, we show that the morbid genome of ciliopathies encompasses many founder mutations, the combined carrier frequency of which accounts for a high disease burden in the study population. CONCLUSIONS: Our study increases our understanding of the morbid genome of ciliopathies. We also provide the strongest evidence, to date, in support of the classical Mendelian inheritance of Bardet-Biedl syndrome and other ciliopathies.


Subject(s)
Cilia/genetics , Ciliary Motility Disorders/genetics , Ciliopathies/genetics , Encephalocele/genetics , Mutation/genetics , Polycystic Kidney Diseases/genetics , Alleles , Cilia/pathology , Ciliary Motility Disorders/pathology , Ciliopathies/pathology , DNA Mutational Analysis , Encephalocele/pathology , Genetic Association Studies , Genetic Heterogeneity , Genetic Predisposition to Disease , Humans , Phenotype , Polycystic Kidney Diseases/pathology , Retina/metabolism , Retina/pathology , Retinitis Pigmentosa
18.
Hum Genet ; 135(10): 1191-7, 2016 10.
Article in English | MEDLINE | ID: mdl-27503289

ABSTRACT

Primary microcephaly is a clinical phenotype in which the head circumference is significantly reduced at birth due to abnormal brain development, primarily at the cortical level. Despite the marked genetic heterogeneity, most primary microcephaly-linked genes converge on mitosis regulation. Two consanguineous families segregating the phenotype of severe primary microcephaly, spasticity and failure to thrive had overlapping autozygomes in which exome sequencing identified homozygous splicing variants in CIT that segregate with the phenotype within each family. CIT encodes citron, an effector of the Rho signaling that is required for cytokinesis specifically in proliferating neuroprogenitors, as well as for postnatal brain development. In agreement with the critical role assigned to the kinase domain in effecting these biological roles, we show that both splicing variants predict variable disruption of this domain. The striking phenotypic overlap between CIT-mutated individuals and the knockout mice and rats that are specifically deficient in the kinase domain supports the proposed causal link between CIT mutation and primary microcephaly in humans.


Subject(s)
Genetic Predisposition to Disease , Intracellular Signaling Peptides and Proteins/genetics , Microcephaly/genetics , Protein Serine-Threonine Kinases/genetics , Animals , Brain/growth & development , Brain/pathology , Child , Cytokinesis/genetics , Female , Genetic Heterogeneity , Humans , Infant, Newborn , Mice , Mice, Knockout , Microcephaly/pathology , Mitosis/genetics , Mutation , Rats , Saudi Arabia , Signal Transduction
19.
Hum Genet ; 135(11): 1233-1239, 2016 Nov.
Article in English | MEDLINE | ID: mdl-27417436

ABSTRACT

Laterality defects are heterogeneous groups of congenital malformations that arise from perturbed asymmetrical development of visceral organs. The central role of the motile cilia-generated nodal flow in breaking early embryonic symmetry is reflected in the large contribution of ciliary genes to the etiology of these disorders. In a consanguineous multiplex family with a laterality defect that resembles situs inversus totalis, and complex congenital heart disease, we combined autozygome and exome analysis to identify a novel homozygous variant in ANKS3. ANKS3 encodes a recently described ciliary protein with known interaction with other ciliary proteins, and deficiency of its zebrafish ortholog causes laterality defects. Consistent with the proposed role of the ANKS3 variant in the pathogenesis of the reported family's phenotype, we show that the mutant RNA failed to rescue the laterality defect in anks3 morphants compared to wild-type RNA. Furthermore, we describe a new mutant anks3 line that also displays laterality defect in the homozygous state. Our study suggests a role for ANKS3 in right-left axis determination in humans.


Subject(s)
Carrier Proteins/genetics , Cilia/genetics , Heart Diseases/genetics , Heterotaxy Syndrome/genetics , Zebrafish/growth & development , Animals , Body Patterning/genetics , Cilia/pathology , Embryonic Development/genetics , Exome/genetics , Heart Diseases/pathology , Heterotaxy Syndrome/pathology , Humans , Mutation , Zebrafish/genetics
20.
Int J Biol Macromol ; 92: 56-62, 2016 Nov.
Article in English | MEDLINE | ID: mdl-27327909

ABSTRACT

Dextrans enzymatic synthesis by immobilized Enterococcus faecalis Esawy dextransucrase was studied. Different parameters, such as: enzyme protein concentration (EPC), substrate concentration (SC), temperature and reaction time were evaluated. EPC played a fundamental role in controlling dextran molecular size with 0.1% dextran in reaction mixture. Dextran 38,397 and 125,471Da were yielded at EPC 4.78 and 5.78mg, respectively. Proper dextrans (73,378 and 117,521Da) demanded in pharmaceutical applications were achieved at 6% and 12% sucrose concentrations and at 4.78 and 5.78mg EPC, respectively. Optimum temperature for conversion of glucose to dextran was 30°C (73% and 80% at 5.78 and 4.78mg EPC, respectively). Varieties of maltooligosaccharides (MOS) were yielded by synergistic cooperation between sucrose and maltose. Six MOS and three dextrans samples in vitro have prebiotic effect on Lactobacillus casei with degree of variation. Two samples of MOS with different degree of polymerization (DP) and three samples of dextran with different molecular weight (MW) reported different fibrinolytic activity.


Subject(s)
Enterococcus faecalis/metabolism , Glucosyltransferases/biosynthesis , Cells, Immobilized/chemistry , Cells, Immobilized/metabolism , Enterococcus faecalis/chemistry , Glucosyltransferases/chemistry , Lacticaseibacillus casei/chemistry , Lacticaseibacillus casei/metabolism
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