Although somatic mutations in Histone 3.3 (H3.3) are well-studied drivers of oncogenesis, the role of germline mutations remains unreported.
View Article and Find Full Text PDFBackground: The X-chromosome gene USP9X encodes a deubiquitylating enzyme that has been associated with neurodevelopmental disorders primarily in female subjects. USP9X escapes X inactivation, and in female subjects de novo heterozygous copy number loss or truncating mutations cause haploinsufficiency culminating in a recognizable syndrome with intellectual disability and signature brain and congenital abnormalities. In contrast, the involvement of USP9X in male neurodevelopmental disorders remains tentative.
View Article and Find Full Text PDFPurpose: Chromosomal microarray (CMA) is recommended as the first-tier test in evaluation of individuals with neurodevelopmental disability and congenital anomalies. CMA may not detect balanced cytogenomic abnormalities or uniparental disomy (UPD), and deletion/duplications and regions of homozygosity may require additional testing to clarify the mechanism and inform accurate counseling. We conducted an evidence review to synthesize data regarding the benefit of additional testing after CMA to inform a genetic diagnosis.
View Article and Find Full Text PDFCHARGE syndrome is a dominant disorder characterized by ocular colobomata, heart defects, choanal atresia, retardation of growth and development, genital hypoplasia, and ear abnormalities including deafness and vestibular disorders. The majority of individuals with CHARGE have pathogenic variants in the gene encoding CHD7, a chromatin remodeling protein. Here, we present a 15-year-old girl with clinical features of CHARGE syndrome and a de novo 6.
View Article and Find Full Text PDFWe describe an X-linked genetic syndrome associated with mutations in TAF1 and manifesting with global developmental delay, intellectual disability (ID), characteristic facial dysmorphology, generalized hypotonia, and variable neurologic features, all in male individuals. Simultaneous studies using diverse strategies led to the identification of nine families with overlapping clinical presentations and affected by de novo or maternally inherited single-nucleotide changes. Two additional families harboring large duplications involving TAF1 were also found to share phenotypic overlap with the probands harboring single-nucleotide changes, but they also demonstrated a severe neurodegeneration phenotype.
View Article and Find Full Text PDFProtein phosphatase 2A (PP2A) is a heterotrimeric protein serine/threonine phosphatase and is involved in a broad range of cellular processes. PPP2R5D is a regulatory B subunit of PP2A and plays an important role in regulating key neuronal and developmental regulation processes such as PI3K/AKT and glycogen synthase kinase 3 beta (GSK3β)-mediated cell growth, chromatin remodeling, and gene transcriptional regulation. Using whole-exome sequencing (WES), we identified four de novo variants in PPP2R5D in a total of seven unrelated individuals with intellectual disability (ID) and other shared clinical characteristics, including autism spectrum disorder, macrocephaly, hypotonia, seizures, and dysmorphic features.
View Article and Find Full Text PDFChromosomal microarray analysis (CMA) for unexplained anomalies and developmental delay has improved diagnosis rates, but results classified as variants of uncertain significance (VUS) may challenge both clinicians and families. We explored the impact of such results on families, including parental knowledge, understanding and interpretation. Semi-structured telephone interviews were conducted with parents (N = 14) who received genetic counseling for a VUS in their child.
View Article and Find Full Text PDFBackground: The aim of this report was to present a rare case of an adolescent with multinodular goiter (MNG) found to have a DICER1 mutation.
Methods And Results: The methodology includes a presentation and discussion of a chart review including endocrine hormone tests, thyroid ultrasound, and genetic testing for DICER1. A 12-year-old girl presented with a diffusely enlarged thyroid gland.
Our objective was to describe: 1) physicians' knowledge of whether genetic counseling is provided to parents of newborns with sickle cell trait (SCT) or who are cystic fibrosis carriers (CFC), and 2) the prevalence of genetic counseling provided by primary care physicians. We conducted a cross-sectional descriptive survey of 600 randomly-sampled Michigan-based pediatricians and family physicians, assessing physician knowledge of where and whether genetic counseling is received by parents whose newborns are carriers. Chi-squared testing determined associations between genetic counseling location and physician demographic characteristics.
View Article and Find Full Text PDFNager syndrome, first described more than 60 years ago, is the archetype of a class of disorders called the acrofacial dysostoses, which are characterized by craniofacial and limb malformations. Despite intensive efforts, no gene for Nager syndrome has yet been identified. In an international collaboration, FORGE Canada and the National Institutes of Health Centers for Mendelian Genomics used exome sequencing as a discovery tool and found that mutations in SF3B4, a component of the U2 pre-mRNA spliceosomal complex, cause Nager syndrome.
View Article and Find Full Text PDFPatient letters provide a permanent record of the genetic counseling that was provided and are unique in medical care; rarely do other health care providers send summaries written specifically to their patients and families. We surveyed genetic counseling training program directors and found that while the acquisition of patient letter-writing skills was considered important, there were no specific guidelines made available to students. To develop letter-writing guidelines, we evaluated patient letters, reviewed references on professional correspondence, surveyed the medical literature, and worked with a writing consultant.
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