Spectrum of genetic disorders and gene variants in the United Arab Emirates national population: insights from the CTGA database.

Like many other Arab countries, the United Arab Emirates (UAE) has a relatively high prevalence of genetic disorders. Here we present the first review and analysis of all genetic disorders and gene variants reported in Emirati nationals and hosted on the Catalogue for Transmission Genetics in Arabs (CTGA), an open-access database hosting bibliographic data on human gene variants associated with inherited or heritable phenotypes in Arabs. To date, CTGA hosts 665 distinct genetic conditions that have been described in Emiratis, 621 of which follow a clear Mendelian inheritance.

Clinical and Molecular Update on the Fourth Reported Family with Hamamy Syndrome.

We report on 2 cousins, a girl and a boy, born to first-cousin Lebanese parents with Hamamy syndrome, exhibiting developmental delay, intellectual disability, severe telecanthus, abnormal ears, dentinogenesis imperfecta, and bone fragility. Whole-exome sequencing studies performed on the 2 affected individuals and one obligate carrier revealed the presence of a homozygous c.503G>A (p.

Catalogue for Transmission Genetics in Arabs (CTGA) Database: Analysing Lebanese Data on Genetic Disorders.

Lebanon has a high annual incidence of birth defects at 63 per 1000 live births, most of which are due to genetic factors. The Catalogue for Transmission Genetics in Arabs (CTGA) database, currently holds data on 642 genetic diseases and 676 related genes, described in Lebanese subjects. A subset of disorders (14/642) has exclusively been described in the Lebanese population, while 24 have only been reported in CTGA and not on OMIM.

A 20-year Clinical and Genetic Neuromuscular Cohort Analysis in Lebanon: An International Effort.

Background: Clinical and molecular data on the occurrence and frequency of inherited neuromuscular disorders (NMD) in the Lebanese population is scarce.

Objective: This study aims to provide a retrospective overview of hereditary NMDs based on our clinical consultations in Lebanon.

Methods: Clinical and molecular data of patients referred to a multi-disciplinary consultation for neuromuscular disorders over a 20-year period (1999-2019) was reviewed.

Developmental delay, intellectual disability, short stature, subglottic stenosis, hearing impairment, onychodysplasia of the index fingers, and distinctive facial features: A newly reported autosomal recessive syndrome.

We report on a multiply consanguineous Syrian family where two siblings, a boy and a girl, presented with a compilation of symptoms including developmental delay, severe intellectual disability, absent speech, hearing impairment, short stature, subglottic stenosis, increased length of the palpebral fissures, onychodysplasia of index fingers, scoliosis, genu valgum, and malpositioned toes. Two other individuals from the extended family with similar clinical features are also described. Array-CGH did not reveal any pathological copy number variation.

Further Delineation of the Disorder: Report on a New Family and Review.

Pathogenic variants in the gene were recently found to be associated in three consanguineous families, with microcephaly, epilepsy, and brain malformations. Here, we report on a 3.5-year-old boy, born to consanguineous Lebanese parents, who presented with developmental delay, lactic acidosis, postnatal microcephaly, and abnormal brain magnetic resonance imaging.

Expanded PCH1D phenotype linked to EXOSC9 mutation.

Pontocerebellar Hypoplasia type 1 is a rare heterogeneous neurodegenerative disorder with multiple subtypes linked to dysfunction of the exosome complex. Patients with mutations in exosome subunits exhibit a generally lethal phenotype characterized by cerebellar and pontine hypoplasia in association with spinal motor neuropathy and multiple systemic and neurologic features. Recently, two variants in the novel PCH1 associated protein EXOSC9 p.

A novel PDE6D mutation in a patient with Joubert syndrome type 22 (JBTS22).

Joubert syndrome (JS) is an autosomal or X-linked recessive syndrome principally characterized by hypotonia, ataxia, cognitive impairment, and a specific finding on brain imaging called a "molar tooth sign" (MTS), which can be isolated or in conjunction with variable organ involvement. The genetic basis of JS is heterogeneous, with over 35 ciliary genes being implicated in its pathogenesis. However, some of these genes (such as PDE6D) have been associated to JS only in single families, seeking confirmation.

Identification of a novel homozygous UNC80 variant in a child with infantile hypotonia with psychomotor retardation and characteristic facies-2 (IHPRF2).

The UNC80 gene encodes for a large component of the NALCN sodium-leak channel complex that regulates the basal excitability of the nervous system. In this study, we report on a novel homozygous mutation in UNC80 in a Palestinian-Emirati patient suffering infantile hypotonia with psychomotor retardation and characteristic facies. This mutation was detected by whole exome sequencing and confirmed using Sanger sequencing in the patient-parents trio.

Novel PDE6A mutation in an Emirati patient with retinitis pigmentosa.

Mutations in the PDE6A gene are known to cause a form of retinitis pigmentosa (RP43), characterized by progressive retinal degeneration. We describe an Emirati patient with RP caused by a novel mutation in PDE6A. Clinical diagnosis of RP was made based on clinical evaluation and electroretinograms.

Single-center experience of N-linked Congenital Disorders of Glycosylation with a Summary of Molecularly Characterized Cases in Arabs.

Congenital disorders of glycosylation (CDG) represent an expanding group of conditions that result from defects in protein and lipid glycosylation. Different subgroups of CDG display considerable clinical and genetic heterogeneity due to the highly complex nature of cellular glycosylation. This is further complicated by ethno-geographic differences in the mutational landscape of each of these subgroups.

Identification of a novel CTCF mutation responsible for syndromic intellectual disability - a case report.

Background: Autosomal dominant mental retardation 21 (MRD21) is a very rare condition, characterized by short stature, microcephaly, mild facial dysmorphisms and intellectual disability that ranged from mild to severe. MRD21 is caused by mutations in CCCTC-binding factor (CTCF) and this was established through only four unrelated cases, two of which had frameshift mutations. CTCF is a master transcriptional regulator that controls chromatin structure and may serve as insulator and transcriptional activator and repressor.

A Novel Variant in the Endothelin-Converting Enzyme-Like 1 (ECEL1) Gene in an Emirati Child.

Objective: The aim of this work was to report a case of an Emirati child who presented with developmental delay and multiple congenital abnormalities that are consistent with distal arthrogryposis type 5D.

Clinical Presentation And Intervention: The clinical presentation comprised contractures of the shoulders, elbows, and knees in addition to camptodactyly and neck pterygium. The facial dysmorphic features noted include ptosis and microretrognathia.

A novel, putatively null, FGD1 variant leading to Aarskog-Scott syndrome in a family from UAE.

Background: The X-linked condition "Aarskog-Scott syndrome (AAS)" causes a characteristic combination of short stature, facial, genital and skeletal anomalies. Studies elucidated a causative link between AAS and mutations in the FGD1 gene, which encodes a Rho/Rac guanine exchange factor. FGD1 is involved in regulating signaling pathways that control cytoskeleton organization and embryogenesis.

Marinesco-Sjögren Syndrome in an Emirati Child with a Novel Mutation in SIL1 Affecting the 5' Untranslated Region.

Objective: The aim of this study was to report clinical and molecular findings in an Emirati child with Marinesco-Sjögren syndrome born to consanguineous parents.

Clinical Presentation And Intervention: The child presented with developmental delay, ataxia, bilateral cataracts, and dysmorphic craniofacial features, along with cerebellar atrophy. Sequencing of the SIL1 gene revealed a novel homozygous large indel mutation that was predicted to abrogate part of the 5' untranslated region (UTR) and the first 30 amino acids of the protein.

Meta-analyses of the association of HLA-DRB1 alleles with rheumatoid arthritis among Arabs.

Aim: Various studies incorporating Arab populations have reported on specific associations between HLA-DRB1 variants and rheumatoid arthritis (RA). We sought to provide an overview on the association of HLA-DRB1 with RA in Arabs using meta-analysis tools.

Methods: Data on allele counts and frequencies were compiled from the relevant literature (published before 16 February 2016) and the associations of 13 -DRB1 variants with RA were assessed; relationships were defined in terms of odds ratios (ORs) with a 95% confidence interval.

Identification of a Novel Homozygous INSR Variant in a Patient with Rabson-Mendenhall Syndrome from the United Arab Emirates.

Background/aims: This study aimed to identify, clinically and molecularly, the causality of Rabson-Mendenhall syndrome in an Emirati family. It is one of the monogenic syndromes of abnormal glucose homeostasis, which result from insulin receptor defects.

Methods: A novel nonsynonymous variant in the INSR gene was uncovered by whole exome sequencing and confirmed using Sanger sequencing in the patient and his parents.

Microcephalic primordial dwarfism in an Emirati patient with PNKP mutation.

Microcephaly is a rare neurological condition, both in isolation and when it occurs as part of a syndrome. One of the syndromic forms of microcephaly is microcephaly, seizures and developmental delay (MCSZ) (OMIM #613402), a rare autosomal recessive neurodevelopmental disorder with a range of phenotypic severity, and known to be caused by mutations in the polynucleotide kinase 3' phosphatase (PNKP) gene. The PNK protein is a key enzyme involved in the repair of single and double stranded DNA breaks, a process which is particularly important in the nervous system.

Novel ECHS1 mutation in an Emirati neonate with severe metabolic acidosis.

ECHS1 is a mitochondrial matrix enzyme that catalyzes an important step in the β-oxidation spiral of fatty acid catabolism, and individuals with mutations in the ECHS1 gene suffer from an autosomal recessive condition typified by delayed psychomotor development, mitochondrial encephalopathy, hypotonia, and cardiomyopathy. Here we report the first Arab case of ECHS1 Deficiency. The patient was born to consanguineous parents with all growth parameters being low for gestational age, and was persistently desaturated.

A novel nonsense GPSM2 mutation in a Yemeni family underlying Chudley-McCullough syndrome.

Mutations in the G Protein Signaling Modulator 2 (GPSM2) cause the autosomal recessive disorder Chudley-McCullough syndrome (CMS), which is characterized by profound congenital sensorineural hearing loss with various abnormalities in the brain. This phenotypic combination is attributed to the role played by GPSM2 in the establishment of planar polarity and spindle orientation during asymmetric cell divisions. Here we present two brothers from a Yemeni family who were diagnosed clinically with CMS then tested for GPSM2 mutations using Sanger sequencing.

Genetics of multifactorial disorders: proceedings of the 6th Pan Arab Human Genetics Conference.

The 6th Pan Arab Human Genetics Conference (PAHGC), "Genetics of Multifactorial Disorders" was organized by the Center for Arab Genomic Studies (http://www.cags.org.

A novel SOX18 mutation uncovered in Jordanian patient with hypotrichosis-lymphedema-telangiectasia syndrome by Whole Exome Sequencing.

The SOX18 gene encodes a transcription factor that plays a notable role in certain developmental contexts such as lymphangiogenesis, hair follicle development and vasculogenesis. SOX18 mutations are linked to recessive and dominant hypotrichosis-lymphedema-telangiectasia syndrome (HLTS). In this study we report on a novel heterozygous mutation in SOX18 in a Jordanian patient suffering from HLTS that was revealed by Whole Exome Sequencing.

Genomics into Healthcare: the 5th Pan Arab Human Genetics Conference and 2013 Golden Helix Symposium.

The joint 5th Pan Arab Human Genetics conference and 2013 Golden Helix Symposium, "Genomics into Healthcare" was coorganized by the Center for Arab Genomic Studies (http://www.cags.org.