RESUMO
The ALF transcription factor paralogs, AFF1, AFF2, AFF3, and AFF4, are components of the transcriptional super elongation complex that regulates expression of genes involved in neurogenesis and development. We describe an autosomal dominant disorder associated with de novo missense variants in the degron of AFF3, a nine amino acid sequence important for its binding to ubiquitin ligase, or with de novo deletions of this region. The sixteen affected individuals we identified, along with two previously reported individuals, present with a recognizable pattern of anomalies, which we named KINSSHIP syndrome (KI for horseshoe kidney, NS for Nievergelt/Savarirayan type of mesomelic dysplasia, S for seizures, H for hypertrichosis, I for intellectual disability, and P for pulmonary involvement), partially overlapping the AFF4-associated CHOPS syndrome. Whereas homozygous Aff3 knockout mice display skeletal anomalies, kidney defects, brain malformations, and neurological anomalies, knockin animals modeling one of the microdeletions and the most common of the missense variants identified in affected individuals presented with lower mesomelic limb deformities like KINSSHIP-affected individuals and early lethality, respectively. Overexpression of AFF3 in zebrafish resulted in body axis anomalies, providing some support for the pathological effect of increased amount of AFF3. The only partial phenotypic overlap of AFF3- and AFF4-associated syndromes and the previously published transcriptome analyses of ALF transcription factors suggest that these factors are not redundant and each contributes uniquely to proper development.
Assuntos
Encefalopatias/genética , Epilepsia/genética , Rim Fundido/genética , Deficiência Intelectual/genética , Mutação de Sentido Incorreto , Proteínas Nucleares/genética , Osteocondrodisplasias/genética , Adolescente , Sequência de Aminoácidos , Animais , Encefalopatias/etiologia , Criança , Pré-Escolar , Epilepsia/complicações , Evolução Molecular , Feminino , Frequência do Gene , Humanos , Lactente , Masculino , Camundongos , Modelos Moleculares , Proteínas Nucleares/química , Proteínas Nucleares/deficiência , Fenótipo , Estabilidade Proteica , Síndrome , Fatores de Elongação da Transcrição/química , Fatores de Elongação da Transcrição/genética , Adulto Jovem , Peixe-Zebra/genéticaRESUMO
INTRODUCTION AND METHODS: We report two series of individuals with DDX3X variations, one (48 individuals) from physicians and one (44 individuals) from caregivers. RESULTS: These two series include several symptoms in common, with fairly similar distribution, which suggests that caregivers' data are close to physicians' data. For example, both series identified early childhood symptoms that were not previously described: feeding difficulties, mean walking age, and age at first words. DISCUSSION: Each of the two datasets provides complementary knowledge. We confirmed that symptoms are similar to those in the literature and provides more details on feeding difficulties. Caregivers considered that the symptom attention-deficit/hyperactivity disorder were most worrisome. Both series also reported sleep disturbance. Recently, anxiety has been reported in individuals with DDX3X variants. We strongly suggest that attention-deficit/hyperactivity disorder, anxiety, and sleep disorders need to be treated.