Genetic and phenotypic findings in 34 novel Spanish patients with DDX3X neurodevelopmental disorder.

DDX3X is a multifunctional ATP-dependent RNA helicase involved in several processes of RNA metabolism and in other biological pathways such as cell cycle control, innate immunity, apoptosis and tumorigenesis. Variants in DDX3X have been associated with a developmental disorder named intellectual developmental disorder, X-linked syndromic, Snijders Blok type (MRXSSB, MIM #300958) or DDX3X neurodevelopmental disorder (DDX3X-NDD). DDX3X-NDD is mainly characterized by intellectual disability, brain abnormalities, hypotonia and behavioral problems. Other common findings include gastrointestinal abnormalities, abnormal gait, speech delay and microcephaly. DDX3X-NDD is predominantly found in females who carry de novo variants in DDX3X. However, hemizygous pathogenic DDX3X variants have been also found in males who inherited their variants from unaffected mothers. To date, more than 200 patients have been reported in the literature. Here, we describe 34 new patients with a variant in DDX3X and reviewed 200 additional patients previously reported in the literature. This article describes 34 additional patients to those already reported, contributing with 25 novel variants and a deep phenotypic characterization. A clinical review of our cohort of DDX3X-NDD patients is performed comparing them to those previously published.

[Consensus of the Genetics Branch of the Chilean Society of Pediatrics on the prioritization of people with Down syndrome and rare diseases for vaccination against SARS-CoV-2]. / Consenso de la Rama de Genética de la Sociedad Chilena de Pediatría sobre priorización de personas con Síndrome de Down y otras condiciones poco frecuentes en la Campaña de Vacunación COVID-19.

In the framework of the vaccination campaign against the SARS-CoV-2 virus, the Chilean Ministry of Health requested advice from the Genetics Branch of the Chilean Society of Pediatrics, to define the level of prioritization for people with Down Syndrome . A panel of geneticists worked on the development of this consensus, in which not only patients with Down syndrome were included, but the search was extended to patients with other types of disabilities, in both pediatric and adult ages in or der to contribute to the development of public health measures against the COVID-19 pandemic. The consensus concludes that, given the prevalence of comorbidities associated with Down syndrome, the higher incidence of cases with severe COVID-19 in this population group and a higher mortality, individuals with trisomy 21 should be considered as a high-risk population, and therefore, vaccina tion against SARS-CoV-2 should have a high priority for all people with Down syndrome regardless of their age (except for the age limit established by the clinical trials of each vaccine), and should be preceded only by the groups of health personnel and adults aged > 60-65 years. Likewise, this group of experts urges health authorities to include people with intellectual disabilities and related conditions as a priority population (other chromosomal abnormalities other than Down syndrome, intellectual disability, congenital anomalies and conditions that cause disability with microcephaly), as well as the caregivers of people with this type of conditions. Vaccination in children with this type of disorders should be considered as part of the first priority group, once safe vaccines against SARS-CoV-2 are available for use in children and adolescents.