BackgroundWWOX, encoding WW domain-containing oxidoreductase, spans FRA16D, the second most common chromosomal fragile site frequently altered in cancers. It is therefore considered a tumor suppressor gene, but its direct implication in cancerogenesis remains controversial.Methods and resultsBy whole-exome sequencing, we identified a homozygous WWOX nonsense mutation, p.Arg54*, in a girl from a consanguineous family with a severe syndrome of growth retardation, microcephaly, epileptic seizures, retinopathy and early death, a phenotype highly similar to the abormalities reported in lde/lde rats with a spontaneous functional null mutation of Wwox. As in rats, no tumors were observed in the patient or heterozygous mutation carriers.ConclusionsOur finding, a homozygous loss-of-function germline mutation in WWOX in a patient with a lethal autosomal recessive syndrome, supports an alternative role of WWOX and indicates its importance for human viability.
BackgroundPrimordial dwarfism is a state of extreme prenatal and postnatal growth deficiency, and is characterized by marked clinical and genetic heterogeneity.ResultsTwo presumably unrelated consanguineous families presented with an apparently novel form of primordial dwarfism in which severe growth deficiency is accompanied by distinct facial dysmorphism, brain malformation (microcephaly, agenesis of corpus callosum, and simplified gyration), and severe encephalopathy with seizures. Combined autozygome/exome analysis revealed a novel missense mutation in WDR4 as the likely causal variant. WDR4 is the human ortholog of the yeast Trm82, an essential component of the Trm8/Trm82 holoenzyme that effects a highly conserved and specific (m7G46) methylation of tRNA. The human mutation and the corresponding yeast mutation result in a significant reduction of m7G46 methylation of specific tRNA species, which provides a potential mechanism for primordial dwarfism associated with this lesion, since reduced m7G46 modification causes a growth deficiency phenotype in yeast.ConclusionOur study expands the number of biological pathways underlying primordial dwarfism and adds to a growing list of human diseases linked to abnormal tRNA modification.Electronic supplementary materialThe online version of this article (doi:10.1186/s13059-015-0779-x) contains supplementary material, which is available to authorized users.
The genetic cause of GAPO syndrome, a condition characterized by growth retardation, alopecia, pseudoanodontia, and progressive visual impairment, has not previously been identified. We studied four ethnically unrelated affected individuals and identified homozygous nonsense mutations (c.262C>T [p.Arg88*] and c.505C>T [p.Arg169*]) or splicing mutations (c.1435-12A>G [p.Gly479Phefs*119]) in ANTXR1, which encodes anthrax toxin receptor 1. The nonsense mutations predictably trigger nonsense-mediated mRNA decay, resulting in the loss of ANTXR1. The transcript with the splicing mutation theoretically encodes a truncated ANTXR1 containing a neopeptide composed of 118 unique amino acids in its C terminus. GAPO syndrome's major phenotypic features, which include dental abnormalities and the accumulation of extracellular matrix, recapitulate those found in Antxr1-mutant mice and point toward an underlying defect in extracellular-matrix regulation. Thus, we propose that mutations affecting ANTXR1 function are responsible for this disease's characteristic generalized defect in extracellular-matrix homeostasis.
Thalassemia is a disorder of hemoglobin (Hb) synthesis characterized by chronic hemolysis. In β-thalassemias major (β-TM), patients require regular transfusion at an early age due to severe anemia. Subsequently, intensive chelation therapy is initiated to mitigate the effects of the resultant iron overload. Clinical disease burden and the demanding treatment can affect health-related quality of life (HRQoL) outcomes in this population. The aim of this study was to assess HRQoL outcomes in Egyptian pediatric thalassemia patients. Patients were enrolled simultaneously from the hematology clinic at the National Research Institute in Cairo, Egypt. The Arabic version of SF36 tool was used to assess HRQoL outcomes. Socioeconomic data were collected by patient and parent interviews. Clinical data were collected by review of medical records. One hundred and thirty patients and 60 controls were enrolled, with a mean age of 5.4 ± 3.2 years and 6.3 ± 3.0, respectively. The HRQoL outcome scores were lower in all domains in the thalassemia group compared to the control group (p = 0.0001). Transfusion-dependent (TD) patients had lower HRQoL scores compared to nontransfusion-dependent (NTD) patients (p = 0.0001). Patient education and maternal education were independently associated with better HRQoL scores (p = 0.007, p = 0.028, respectively). Residents of rural areas reported lower scores compared to urban residents (p = 0.026). Thalassemia was associated with lower HRQoL scores, in all domains, compared to HRQoL in unaffected controls. Chronic transfusion independence, patient education, and maternal education were all associated with higher HRQoL scores. Psychological, social, and economic support for families with thalassemia are all essential tools to improve HRQoL outcomes.
IMPORTANCEThe study establishes the importance of genetic background for the expression of Down syndrome phenotype.OBJECTIVE To define the ocular manifestations of Down syndrome in infants and children in Cairo, Egypt, a historically isolated region, and compare them with systemic features and with findings in other geographic groups. DESIGN AND PARTICIPANTSWe prospectively studied the ocular status and systemic features of 90 infants and children with Down syndrome and monitored all patients for 3 years. The complete ophthalmic examinations were performed along with ultrasonography, if media opacities were evident. Thyroid and cardiac status were assessed. An extensive literature search for comparison was performed.SETTING Outpatient clinical genetics department at the National Research Centre in Cairo, Egypt. MAIN OUTCOMES AND MEASURESOcular and systemic manifestations of Down syndrome in infants and children in Cairo, and comparison of these features with patients with this anomaly from other geographic regions and ethnic populations.RESULTS Fifty-two infants or children (58%) had at least 1 abnormal ocular finding identified at the first visit. Significant refractive errors (in 37 [41%] patients) were the most common. Nasolacrimal duct obstruction, blepharoconjuctivitis, or conjunctivitis was found in 18 (20%), strabismus in 13 (14%), cataract in 5 (6%), nystagmus in 3 (3%), and optic nerve dysplasia in 2 (2%). Brushfield spots were not found. Additional ocular features developed over time. Thirty-six patients (40%) had congenital heart defects, and many (31 [86%]) had associated ocular disorders; a statistically significant correlation with myopia was established. Chromosomal translocations were high. The phenotype in Cairo was distinct.CONCLUSIONS AND RELEVANCE More than half of infants and children with Down syndrome in Cairo had ophthalmic abnormalities; myopia was correlated with congenital heart defects. Comparison of the specific ocular features in our population with those in previous worldwide studies shows differences that may be related to overexpression or polymorphisms of key, modifying genes or other mutations in this historically isolated region along the Nile River. Down syndrome is more common in the highly consanguineous and multiparous Middle Eastern populations, and our Cairo findings underscore regional differences.
blood absorption. The results show that the normal skin developed a greater skin colour change at the final stage of irradiation. Although the vitiligo-involved site also shows an increase of the area under the curve, the small magnitude of change was not significant to detect pigment formation clinically. Figure 2(b) displays the correlation of the constitutive melanin content of normal skin to the degree of formation of IPD. The amount of constitutive melanin is quantified by an area of differential apparent absorbance between normal and vitiligoinvolved skin at baseline in the spectral range of 390-450 nm in which the soluble fraction of epidermal melanin predominantly contributes to the apparent absorbance. 9 The result shows that the degree of IPD response appears to be related to the constitutive pigment expressed at short wavelengths.In this study, we found that VIS-NIR radiation produces IPD only in normally pigmented skin and that the presence of constitutive pigment is required to induce IPD response. We conclude that the degree of formation of IPD from VIS-NIR radiation is related to the content of constitutive pigment expressed at short wavelengths (390-450 nm). This relation has been confirmed in an ongoing study on healthy subjects with various skin types.
We report on a 3‐year‐old boy with growth retardation, alopecia, pseudoanodontia, and optic atrophy. This is the 18th known and the first Egyptian case of GAPO syndrome. Electron microscopic examination of gingival biopsy showed excessive collagen fibres and endothelial vacuolisation, suggesting involvement of extracellular pathological collagenosis.
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