RESUMEN
Exome sequencing has markedly enhanced the discovery of genes implicated in Mendelian disorders, particularly for individuals in whom a known clinical entity could not be assigned. This has led to the recognition that phenotypic heterogeneity resulting from allelic mutations occurs more commonly than previously appreciated. Here, we report that missense variants in CDC42, a gene encoding a small GTPase functioning as an intracellular signaling node, underlie a clinically heterogeneous group of phenotypes characterized by variable growth dysregulation, facial dysmorphism, and neurodevelopmental, immunological, and hematological anomalies, including a phenotype resembling Noonan syndrome, a developmental disorder caused by dysregulated RAS signaling. In silico, in vitro, and in vivo analyses demonstrate that mutations variably perturb CDC42 function by altering the switch between the active and inactive states of the GTPase and/or affecting CDC42 interaction with effectors, and differentially disturb cellular and developmental processes. These findings reveal the remarkably variable impact that dominantly acting CDC42 mutations have on cell function and development, creating challenges in syndrome definition, and exemplify the importance of functional profiling for syndrome recognition and delineation.
Asunto(s)
Anomalías Múltiples/genética , Anomalías Craneofaciales/genética , Heterogeneidad Genética , Atrofia Muscular/genética , Mutación Missense , Trastornos del Neurodesarrollo/genética , Síndrome de Noonan/genética , Proteína de Unión al GTP cdc42/genética , Anomalías Múltiples/metabolismo , Anomalías Múltiples/patología , Adolescente , Adulto , Niño , Preescolar , Anomalías Craneofaciales/metabolismo , Anomalías Craneofaciales/patología , Femenino , Expresión Génica , Humanos , Lactante , Masculino , Modelos Moleculares , Atrofia Muscular/metabolismo , Atrofia Muscular/patología , Trastornos del Neurodesarrollo/metabolismo , Trastornos del Neurodesarrollo/patología , Síndrome de Noonan/metabolismo , Síndrome de Noonan/patología , Fenotipo , Estructura Secundaria de Proteína , Índice de Severidad de la Enfermedad , Proteína de Unión al GTP cdc42/química , Proteína de Unión al GTP cdc42/metabolismoRESUMEN
[This corrects the article DOI: 10.1155/2020/7353452.].
RESUMEN
Despite significant advances in perinatal and neonatal medicine, infant mortality (IM) remains a significant public health problem. The causes of IM are complex, numerous, and a result of interacting genetic and environmental factors. This paper explores genetic contributions to IM using data from Virginia. Leading causes of IM in Virginia are disorders of prematurity/low birth weight, congenital anomalies, and sudden infant death syndrome (SIDS). Recognized single gene disorders as well as genetic polymorphisms are discussed in relation to their role in IM. While preconceptional prevention from a genetic standpoint may not currently be possible, this paper provides clinicians with information on identifying women at highest risk for IM and those in need of additional surveillance and intervention. Suggestions for simple health messages to provide to women of child-bearing age to decrease the risks for birth defects and obstetrical/perinatal complications resulting in IM are also discussed.
Asunto(s)
Mortalidad Infantil , Anomalías Congénitas/genética , Femenino , Humanos , Lactante , Recién Nacido , Embarazo , Nacimiento Prematuro/genética , Muerte Súbita del Lactante/genéticaRESUMEN
[This corrects the article DOI: 10.1155/2020/7353452.].
RESUMEN
Shprintzen-Goldberg craniosynostosis syndrome (SGS) is a rare autosomal dominant condition that was first documented in literature in 1982. The disorder is caused by pathogenic variants in the proto-oncogene SKI gene, a known suppressor of TGF-ß activity, located on chromosome 1p36. There is considerable phenotypic overlap with Marfan and Loeys-Dietz syndromes. Common clinical features of SGS include craniosynostosis, marfanoid habitus, hypotonia, dysmorphic facies, cardiovascular anomalies, and other skeletal and connective tissue abnormalities. Ocular manifestations may include hypertelorism, downslanting palpebral fissures, proptosis, myopia, and ectopia lentis. We describe a 25-year-old male with the syndrome. Genetic analysis revealed a novel c.350G>A (p.Arg117His) de novo variant, which was predicted to be pathogenic by the CTGT laboratory. The patient presented with dysmorphic features, marfanoid habitus, severe joint contractures, mitral valve insufficiency, aortic root dilatation, and a history of seizures. His ocular manifestations included hypertelorism, downslanting palpebral fissures, bilateral ptosis, and high myopia. Ophthalmic manifestations are an integral component of the syndrome; however, they have not been well characterized in the literature. From a systematic review of previously published cases to date, we summarize the eye and ocular adnexa manifestations reported.