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.

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.

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.

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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.