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After years of decline, tuberculosis has reemerged as a serious public health problem worldwide. Factors contributing to this resurgence include the HIV epidemic and immigration of people from countries with a high incidence of tuberculosis. In 1993, the World Health Organization (WHO) declared it to be a ‘global emergency’ and according to a recent WHO report, there were 7.96 million new cases in 1996, with two million deaths.Comprehensive up-to-date information is available via the Internet, which has emerged as an essential tool for information on a wide variety of subjects including tuberculosis. However, looking for the right information on tuberculosis can be laborious, especially with the enormous number of tuberculosis websites established. It is always helpful to know which ones to visit to avoid wasting valuable time.This article provides readers with a list of websites that provide information on tuberculosis. All sites quoted here have been tested and proven to be valuable and informative for both the public and scientific community alike. [ABSTRACT FROM PUBLISHER]

The genetics revolution is in full swing, especially following the recent release of the complete human genome sequence which will change forever the world in which we live by providing potential for new drugs and therapies and the means of preventing inherited genetic diseases. As a result of establishing the whole human genome sequence and the associated media publicity, the general public have become familiar with and more eager to learn about the subject of genetics and its potential impact on both their own lives and those of their families.One of the main sources of information available to the public today is the World Wide Web. Vast amounts of information are contained in the numerous websites available through the Internet. However, finding the right information can be very tedious, especially with the huge number of websites currently available.This article guides the public to key websites and webpages that cover information on genetics. All sites listed here have been tested and proven to be beneficial and informative. [ABSTRACT FROM PUBLISHER]

The prevalence of primary congenital glaucoma (PCG) in Saudi Arabia is high and the condition is a cause of childhood blindness in the country. Children often present with severe disease, requiring multiple procedures and a lifetime of medical care. The social and economic burden of the condition is substantial. Presently, the mainstay of management is early diagnosis and treatment of PCG. Premarital screening, especially in recessive diseases, such as PCG can be immensely useful by detecting the presence of a defect in the causative gene, followed by genetic counseling to potential couples that will lead to eradication of the disease in future generations. The introduction of a national screening program similar to the one already functioning for thalassemia, could potentially eliminate childhood blindness from PCG in Saudi Arabia and is likely to prove cost-effective.

Exfoliation syndrome (XFS) is the most common known risk factor for secondary glaucoma and a major cause of blindness worldwide. Variants in two genes, LOXL1 and CACNA1A, have previously been associated with XFS. To further elucidate the genetic basis of XFS, we collected a global sample of XFS cases to refine the association at LOXL1, which previously showed inconsistent results across populations, and to identify new variants associated with XFS. We identified a rare protective allele at LOXL1 (p.Phe407, odds ratio (OR) = 25, P = 2.9 × 10 -14 ) through deep resequencing of XFS cases and controls from nine countries. A genome-wide association study (GWAS) of XFS cases and controls from 24 countries followed by replication in 18 countries identified seven genome-wide significant loci (P < 5 × 10 -8 ). We identified association signals at 13q12 (POMP), 11q23.3 (TMEM136), 6p21 (AGPAT1), 3p24 (RBMS3) and 5q23 (near SEMA6A). These findings provide biological insights into the pathology of XFS and highlight a potential role for naturally occurring rare LOXL1 variants in disease biology.

Motor, sensory, and integrative activities of the brain are coordinated by a series of midline-bridging neuronal commissures whose development is tightly regulated. Here we report a new human syndrome in which these commissures are widely disrupted, thus causing clinical manifestations of horizontal gaze palsy, scoliosis, and intellectual disability. Affected individuals were found to possess biallelic loss-of-function mutations in the gene encoding the axon-guidance receptor 'deleted in colorectal carcinoma' (DCC), which has been implicated in congenital mirror movements when it is mutated in the heterozygous state but whose biallelic loss-of-function human phenotype has not been reported. Structural MRI and diffusion tractography demonstrated broad disorganization of white-matter tracts throughout the human central nervous system (CNS), including loss of all commissural tracts at multiple levels of the neuraxis. Combined with data from animal models, these findings show that DCC is a master regulator of midline crossing and development of white-matter projections throughout the human CNS.

Introduction: Congenital fibrosis of the extraocular muscles type 2 (CFEOM2) is a distinct non-syndromic form of congenital incomitant strabismus secondary to orbital dysinnervation from recessive mutations in the gene PHOX2A. The phenotype includes bilateral ptosis, very large angle exotropia, ophthalmoplegia, and poorly-reactive pupils. Other than amblyopia, afferent visual dysfunction has not been considered part of CFEOM2; however, we have repeatedly observed non-amblyopic subnormal vision in affected patients. The purpose of this study was to document this recurrent feature of the phenotype., Methods: A retrospective case series (2002-2012)., Results: Eighteen patients (four families) were identified; all affected individuals had confirmed homozygous recessive PHOX2A mutations except one individual for whom genetic testing was not done because of multiple genetically confirmed family members. Age at assessment ranged from 5-62 years old (median 10 years old). All patients had decreased best-corrected visual acuity not completely explainable by amblyopia in both the preferred and non-preferred eye. In those patients who had further ancillary testing, visual fields (five patients) and electroretinography (10 patients) confirmed abnormalities not ascribable to amblyopia., Conclusions: In addition to a distinct form of congenital incomitant strabismus, the phenotype of CFEOM2 includes subnormal vision consistent with retinal dysfunction. This could be the direct result of PHOX2A mutations or a secondary effect of orbital dysinnervation.

Primary angle closure glaucoma (PACG) is a major cause of blindness worldwide. We conducted a genome-wide association study (GWAS) followed by replication in a combined total of 10,503 PACG cases and 29,567 controls drawn from 24 countries across Asia, Australia, Europe, North America, and South America. We observed significant evidence of disease association at five new genetic loci upon meta-analysis of all patient collections. These loci are at EPDR1 rs3816415 (odds ratio (OR) = 1.24, P = 5.94 × 10(-15)), CHAT rs1258267 (OR = 1.22, P = 2.85 × 10(-16)), GLIS3 rs736893 (OR = 1.18, P = 1.43 × 10(-14)), FERMT2 rs7494379 (OR = 1.14, P = 3.43 × 10(-11)), and DPM2-FAM102A rs3739821 (OR = 1.15, P = 8.32 × 10(-12)). We also confirmed significant association at three previously described loci (P < 5 × 10(-8) for each sentinel SNP at PLEKHA7, COL11A1, and PCMTD1-ST18), providing new insights into the biology of PACG.

Epidemiological studies suggest that by 2020 the prevalence of primary open angle glaucoma (POAG) is estimated to increase to 76.0 million, and to 111.8 million by 2040 globally due to the population aging. The prevalence of POAG is the highest among those of African descent, followed by Asians, and the lowest in Europeans. POAG is a genetically complex trait with a substantial fraction exhibiting a significant heritability. Less than 10% of POAG cases in the general population are caused by specific gene mutations and the remaining cases are polygenic. Quantitative traits related to POAG pathogenesis such as intra-ocular pressure (IOP), vertical cup/disc ratio (VCDR), optic disc area, and central corneal thickness (CCT) are highly heritable, and likely to be influenced at least in part by genes and show substantial variation in human populations. Recent genome-wide association studies (GWAS) have identified several single nucleotide polymorphisms (SNPs) at different loci including CAV1/CAV2, TMCO1, CDKN2B-AS1, CDC7-TGFBR3, SIX1/SIX6, GAS7 and ATOH7 to be associated with POAG and its related quantitative traits (endophenotypes). The chapter provides a brief overview on the different GWAS and SNP association studies and their correlation with various clinical parameters important for POAG in the population worldwide, including the Middle East.

Children affected by infantile esotropia can cross-fixate to see object to the contralateral side with the adducted eye; when doing so they need not abduct the eye ipsilateral to the object and thus can appear to have abduction defects. Less commonly, an esotropic child is truly unable to abduct and cross-fixates to allow side gaze. We report the case of a 10-month-old girl with cross-fixation and inability to abduct who was genetically proven to have horizontal gaze palsy with progressive scoliosis (recessive ROBO3 mutations). Clinical assessment of her elder brother, previously diagnosed with bilateral type 3 Duane retraction syndrome, revealed that he was actually affected by the same disease. We highlight this rare ocular motility disorder as part of the differential diagnosis of early childhood esotropia with cross-fixation and inability to abduct and how examination of an affected sibling can facilitate proper diagnosis of genetic eye disease., (Copyright © 2014 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.)

Background and Objectives: The prevalence of maturity-onset diabetes of the young (MODY) in Saudi population remains unknown, and data on molecular etiology of this condition is limited. Therefore, the present study was undertaken to elucidate clinical and molecular characteristics of a Saudi family with MODY 1., Design and Settings: This is a case series study conducted at Saad Specialist Hospital in Alkhobar, Saudi Arabia., Patients and Methods: A 12-year-old female presented to us with symptoms suggestive of diabetes. Investigations revealed hyperglycemia, glycosuria, and ketonuria without acidosis. Pancreatic antibodies were negative. She responded well to subcutaneous insulin. Her family history revealed that 2 of her siblings were diagnosed with type 1 diabetes (T1DM), while her father and mother had type 2 diabetes (T2DM). In view of this strong family history, the possibility of monogenic diabetes was raised, and the 2 genes consistent with this phenotype, hepatocyte nuclear factor-1 alpha (HNF1a) and hepatocyte nuclear factor-4 alpha (HNF4a), were studied. Accordingly, genomic DNA was isolated from peripheral blood lymphocytes of the 8 members of this family, polymerase chain reaction was carried out, and sequencing of the whole HNF4a and HNF1a genes was done., Results: DNA study of the proband revealed a heterozygous substitution in intron 1 (IVS1b C > T-5)(c.50-5C > T) of the HNF1a gene. This mutation was identified in other 5 members of the family., Conclusion: This study alerts physicians to suspect MODY in patients who have a strongly positive family history of diabetes over a few generations with negative pancreatic antibodies and absence of ketoacidosis and obesity.

Anterior chamber depth (ACD) is a key anatomical risk factor for primary angle closure glaucoma (PACG). We conducted a genome-wide association study (GWAS) on ACD to discover novel genes for PACG on a total of 5,308 population-based individuals of Asian descent. Genome-wide significant association was observed at a sequence variant within ABCC5 (rs1401999; per-allele effect size =  -0.045 mm, P = 8.17 × 10(-9)). This locus was associated with an increase in risk of PACG in a separate case-control study of 4,276 PACG cases and 18,801 controls (per-allele OR = 1.13 [95% CI: 1.06-1.22], P = 0.00046). The association was strengthened when a sub-group of controls with open angles were included in the analysis (per-allele OR = 1.30, P = 7.45 × 10(-9); 3,458 cases vs. 3,831 controls). Our findings suggest that the increase in PACG risk could in part be mediated by genetic sequence variants influencing anterior chamber dimensions.

Different types of mutations have been reported in patients with hemophilia A. Although about half of all severe factor VIII deficiencies are caused by gene rearrangements (inversions) involving intron 22 in F8, other mutations such as point mutation, large deletions and insertions had been reported. We report the result of the first molecular testing for or F8 mutations from Saudi Arabia. A cohort of 22 men with hemophilia A was studied for F8 mutations. All patients were tested for factor VIII coagulant activity and inhibitors. Peripheral blood samples were used for DNA extraction followed by PCR detection of intron 22 inversion and all samples tested negative were screened for other F8 mutations. The patient's age ranged between 4 and 37 years. All patients except two siblings had severe hemophilia A. Only two patients out of 22 developed inhibitors with no obvious relation to the genotype. F8 Intron 22 inversion was detected in 10 patients (50%) of severe cases. Additionally, five point mutations and one deletion/insertion involving different exons were detected. All identified mutations were associated with severe phenotype except for one, which was associated with mild phenotype of hemophilia. This is the first report of molecular genotype of hemophilia A in the Saudi population and one of the few for Arab population. We had confirmed the incidence of Inversion 22 in severe hemophilia. We are reporting two novel mutations in F8, which can be used for carrier detection and prenatal genetic diagnosis (PGD).

Brachydactyly type B (BDB) is an autosomal dominant disease caused by mutations in the ROR2 gene. Truncating mutations lead to the severe form of the disease, which is characterized by terminal deficiency of fingers and toes. Preimplantation genetic diagnosis (PGD) was carried out in a family suffering from severe BDB. The family was screened for mutations in exons 8 and 9 and found to harbour a known nonsense mutation (c.2265C-->A) in exon 9 of the ROR2 gene, which resulted in a premature stop-codon at residue 755. Three out of 10 linked markers tested were informative for this family and single cell work-up showed amplification efficiency in over 98% of the cells. Allele drop-out (ADO) was found in 0, 4.08 and 6.1% for D9S1803, D9S1842 and D9S280 respectively. The family underwent PGD using multiple displacement amplification, fluorescent polymerase chain reaction (informative short tandem repeat) and sequencing of exon 9. Two cells were taken from the three embryos generated in the PGD cycle and the diagnosis of both cells separately showed one normal embryo free of BDB abnormal allele. This embryo was transferred back to the mother and resulted in a singleton pregnancy. Postnatal DNA testing of the newborn confirmed the PGD result.

Recurrent IVF failure, implantation failure and early embryo demise can be attributed to the high frequency of chromosomal aneuploidy observed in human embryos. Preimplantation genetic screening (PGS) using multiple displacement amplifications (MDA) and array comparative genomic hybridization (aCGH) was successfully performed on eight patients with a minimum of seven recurrent IVF failures with the aim of detecting aneuploidy and ameliorating pregnancy rate. A total of 41 embryos with eight or more cells were biopsied by taking two blastomeres from each embryo. The DNA from these blastomeres were amplified and analysed by aCGH technology. The aCGH results showed a complex panel of chromosomal abnormalities in 60% of the diagnosed embryos. Some abnormalities could not be detected by the seven-probe panel (13, 16, 18, 21, 22, X and Y) used in fluorescence in-situ hybridization. Six out of eight patients had embryos for transfer with five out of those six showing positive pregnancy tests. As far as is known, this report is the first to show a pregnancy after PGS using the aCGH technology. The pregnancy rate obtained here is encouraging and will open the door for enrollment of more patients.