A novel nonsense variant in expanding the spectrum of White-Sutton syndrome: A case report.

White-Sutton Syndrome (WHSUS) is a rare neurodevelopmental genetic disorder with an autosomal dominant mode of inheritance. Truncating mutations in pogo transposable element with zinc finger domain () gene have been reported in cases of WHSUS. In this article, we present the first diagnosed case of WHSUS in Lebanon.

Novel SCN9A variant associated with congenital insensitivity to pain.

Background: Congenital insensitivity to pain (CIP) is a rare autosomal recessive syndrome characterized by lack of pain perception and a wide spectrum of clinical signs such as anosmia and hyposmia. Variants in SCN9A gene are associated with CIP. We here report on a Lebanese family with three CIP patients referred for genetic investigations.

Analysis of ASS1 gene in ten unrelated middle eastern families with citrullinemia type 1 identifies rare and novel variants.

Background: Citrullinemia type 1 (CTLN1) is a rare autosomal recessive disease caused by argininosuccinate synthetase (ASS) deficiency. Manifestations vary from the acute neonatal or "classic" form to a milder, late-onset, or "unconventional" form. To date, more than 93 variants in the ASS1 gene located on chromosome 9q43.

I vitamin D receptor gene polymorphism and serum 25-hydroxyvitamin D in patients with cardiovascular risk.

Introduction: The biological actions of vitamin D are mediated through vitamin D receptor (VDR). Numerous single-nucleotide polymorphisms (SNPs) in the VDR gene have been identified, and some have been associated with cardiovascular disease (CVD) risk factors. This study aims to evaluate the association of five SNPs in the VDR gene with 25-hydroxyvitamin D (25[OH]D) levels in patients with at least one CVD risk factor.

The added value of WES reanalysis in the field of genetic diagnosis: lessons learned from 200 exomes in the Lebanese population.

Background: The past few decades have witnessed a tremendous development in the field of genetics. The implementation of next generation sequencing (NGS) technologies revolutionized the field of molecular biology and made the genetic information accessible at a large scale. However, connecting a rare genetic variation to a complex phenotype remains challenging.

Contribution of copy number variants (CNVs) to congenital, unexplained intellectual and developmental disabilities in Lebanese patients.

Background: Chromosomal microarray analysis (CMA) is currently the most widely adopted clinical test for patients with unexplained intellectual disability (ID), developmental delay (DD), and congenital anomalies. Its use has revealed the capacity to detect copy number variants (CNVs), as well as regions of homozygosity, that, based on their distribution on chromosomes, indicate uniparental disomy or parental consanguinity that is suggestive of an increased probability of recessive disease.

Results: We screened 149 Lebanese probands with ID/DD and 99 healthy controls using the Affymetrix Cyto 2.

Ex vivo PBMC cytokine profile in familial Mediterranean fever patients: Involvement of IL-1β, IL-1α and Th17-associated cytokines and decrease of Th1 and Th2 cytokines.

In order to clarify the inflammatory mechanism underlying familial Mediterranean fever (FMF), we aimed to evaluate the ex vivo cytokine profile of FMF patients during acute attacks and attack-free periods, and compare it with that of healthy controls. The study included 34 FMF patients, of whom 9 were studied during attack and remission and 24 healthy controls. Cytokine levels were evaluated by Luminex technology in serum and supernatants of PBMC (Peripheral Blood Mononuclear Cells) cultures with and without 24h stimulation of monocytes by LPS and T lymphocytes by anti-CD3/CD28 beads.

Prevalance of BRCA1 and BRCA2 mutations in familial breast cancer patients in Lebanon.

Breast cancer is the most prevalent malignancy in women in Western countries, currently accounting for one third of all female cancers. Familial aggregation is thought to account for 5-10 % of all BC cases, and germline mutations in BRCA1 and BRCA2 account for less of the half of these inherited cases. In Lebanon, breast cancer represents the principal death-causing malignancy among women, with 50 % of the cases diagnosed before the age of 50 years.

Familial Mediterranean fever in a large Lebanese family: multiple MEFV mutations and evidence for a Founder effect of the p.[M694I] mutation.

Familial Mediterranean fever (FMF) is an autoinflammatory autosomal recessive disease characterized by recurrent fever crises and serous inflammation. The MEFV gene responsible for the disease was identified on chromosome 16, and 5 of the mutations discovered so far in the gene are most frequently encountered in FMF patients: p.[M694V], p.

A whole-genome scan in a large family with leukodystrophy and oligodontia reveals linkage to 10q22.

Dentoleukoencephalopathies with autosomal recessive inheritance are very rare. Recently, a large inbred Syrian pedigree was reported with oligodontia in association with a degenerative neurologic condition characterized by progressive ataxia and pyramidal syndrome and abnormalities in the white matter and cortical atrophy. A whole-genome screening of this family using 382 microsatellite markers was completed, but no evidence was found of linkage to any chromosomal region.

CAMOS, a nonprogressive, autosomal recessive, congenital cerebellar ataxia, is caused by a mutant zinc-finger protein, ZNF592.

CAMOS (Cerebellar Ataxia with Mental retardation, Optic atrophy and Skin abnormalities) is a rare autosomal recessive syndrome characterized by a nonprogressive congenital cerebellar ataxia associated with mental retardation, optic atrophy, and skin abnormalities. Using homozygosity mapping in a large inbred Lebanese Druze family, we previously reported the mapping of the disease gene at chromosome 15q24-q26 to a 3.6-cM interval between markers D15S206 and D15S199.

The molecular basis of familial hypercholesterolemia in Lebanon: spectrum of LDLR mutations and role of PCSK9 as a modifier gene.

Autosomal dominant hypercholesterolemia (ADH), a major risk for coronary heart disease, is associated with mutations in the genes encoding the low-density lipoproteins receptor (LDLR), its ligand apolipoprotein B (APOB) or PCSK9 (Proprotein Convertase Subtilin Kexin 9). Familial hypercholesterolemia (FH) caused by mutation in the LDLR gene is the most frequent form of ADH. The incidence of FH is particularly high in the Lebanese population presumably as a result of a founder effect.

Pitfalls of homozygosity mapping: an extended consanguineous Bardet-Biedl syndrome family with two mutant genes (BBS2, BBS10), three mutations, but no triallelism.

The extensive genetic heterogeneity of Bardet-Biedl syndrome (BBS) is documented by the identification, by classical linkage analysis complemented recently by comparative genomic approaches, of nine genes (BBS1-9) that account cumulatively for about 50% of patients. The BBS genes appear implicated in cilia and basal body assembly or function. In order to find new BBS genes, we performed SNP homozygosity mapping analysis in an extended consanguineous family living in a small Lebanese village.

Familial Mediterranean fever in the Syrian population: gene mutation frequencies, carrier rates and phenotype-genotype correlation.

Background: Familial Mediterranean fever (FMF) is an autosomal recessive disease mainly affecting particularly Arabs, Non-Ashkenazi Jews, Armenians, and Turks. It is an autoinflammatory periodic disorder characterized by febrile and painful attacks due to inflammation involving the serosal membranes in the abdomen, chest or joints. Over 50 mutations have been identified in the MEFV gene responsible for FMF.

BBS10 encodes a vertebrate-specific chaperonin-like protein and is a major BBS locus.

Bardet-Biedl syndrome (BBS) is a genetically heterogeneous ciliopathy. Although nine BBS genes have been cloned, they explain only 40-50% of the total mutational load. Here we report a major new BBS locus, BBS10, that encodes a previously unknown, rapidly evolving vertebrate-specific chaperonin-like protein.

Heterozygous and homozygous mutations in PITX3 in a large Lebanese family with posterior polar cataracts and neurodevelopmental abnormalities.

Purpose: The PITX3 gene, which codes for a homeobox bicoidlike transcription factor is responsible for dominant cataract and anterior segment mesenchymal dysgenesis in humans. In the current study, a family with autosomal dominant posterior polar cataract (PPC) and a PITX3 mutation that cosegregates with the disease was examined. Also studied were two siblings who were homozygous for the PITX3 mutation who had microphthalmia and significant neurologic impairment.

Familial Mediterranean fever (FMF) in Lebanon and Jordan: a population genetics study and report of three novel mutations.

Familial Mediterranean fever (FMF) is an autosomal recessive disease mostly frequent in Mediterranean populations. Over 50 mutations have been identified in the gene responsible for the disease, MEFV. The present study reports the frequencies of MEFV mutations in 558 Lebanese and 55 Jordanian FMF patients and points out the severity of the M694V frequently observed mutation among these patients.

Amyloidosis in familial Mediterranean fever patients: correlation with MEFV genotype and SAA1 and MICA polymorphisms effects.

Background: Familial mediterranean fever (FMF) is a recessively inherited disease characterized by recurrent crises of fever, abdominal, articular and/or thoracic pain. The most severe complication is the development of renal amyloidosis. Over 35 mutations have been discovered so far in the gene responsible for the disease, MEFV.

Non-syndromic recessive deafness in Jordan: mapping of a new locus to chromosome 9q34.3 and prevalence of DFNB1 mutations.

Non-syndromic recessive deafness (NSRD) is the most commonly encountered form of hereditary hearing loss. The majority of NSRD cases in the Mediterranean area are linked to the DFNB1 locus (the connexin 26 GJB2 gene). Unrelated NSRD patients issued from 68 Jordanian families, were tested for mutations of the GJB2 gene by sequencing.

A new autosomal recessive non-progressive congenital cerebellar ataxia associated with mental retardation, optic atrophy, and skin abnormalities (CAMOS) maps to chromosome 15q24-q26 in a large consanguineous Lebanese Druze Family.

Congenital cerebellar ataxias are a heterogeneous group of non-progressive disorders characterized by hypotonia and developmental delay followed by the appearance of ataxia, and often associated with dysarthria, mental retardation, and atrophy of the cerebellum. We report the mapping of a disease gene in a large inbred Lebanese Druze family, with five cases of a new form of non-progressive autosomal recessive congenital ataxia associated with optic atrophy, severe mental retardation, and structural skin abnormalities, to a 3.6-cM interval on chromosome 15q24-15q26.