Low-pass whole genome sequencing as a cost-effective alternative to chromosomal microarray analysis for low- and middle-income countries.

Low-pass whole genome sequencing (LP-WGS) has been applied as alternative method to detect copy number variants (CNVs) in the clinical setting. Compared with chromosomal microarray analysis (CMA), the sequencing-based approach provides a similar resolution of CNV detection at a lower cost. In this study, we assessed the efficiency and reliability of LP-WGS as a more affordable alternative to CMA. A total of 1363 patients with unexplained neurodevelopmental delay/intellectual disability, autism spectrum disorders, and/or multiple congenital anomalies were enrolled. Those patients were referred from 15 nonprofit organizations and university centers located in different states in Brazil. The analysis of LP-WGS at 1x coverage (>50kb) revealed a positive testing result in 22% of the cases (304/1363), in which 219 and 85 correspond to pathogenic/likely pathogenic (P/LP) CNVs and variants of uncertain significance (VUS), respectively. The 16% (219/1363) diagnostic yield observed in our cohort is comparable to the 15%-20% reported for CMA in the literature. The use of commercial software, as demonstrated in this study, simplifies the implementation of the test in clinical settings. Particularly for countries like Brazil, where the cost of CMA presents a substantial barrier to most of the population, LP-WGS emerges as a cost-effective alternative for investigating copy number changes in cytogenetics.

Gene expression profiling of bone marrow mesenchymal stem cells from Osteogenesis Imperfecta patients during osteoblast differentiation.

Mesenchymal stem cells (MSCs) are precursors present in adult bone marrow that are able to differentiate into osteoblasts, adipocytes and chondroblasts that have gained great importance as a source for cell therapy. Recently, a number of studies involving the analysis of gene expression of undifferentiated MSCs and of MSCs in the differentiation into multiple lineage processes were observed but there is no information concerning the gene expression of MSCs from Osteogenesis Imperfecta (OI) patients. Osteogenesis Imperfecta is characterized as a genetic disorder in which a generalized osteopenia leads to excessive bone fragility and severe bone deformities. The aim of this study was to analyze gene expression profile during osteogenic differentiation from BMMSCs (Bone Marrow Mesenchymal Stem Cells) obtained from patients with Osteogenesis Imperfecta and from control subjects. Bone marrow samples were collected from three normal subjects and five patients with OI. Mononuclear cells were isolated for obtaining mesenchymal cells that had been expanded until osteogenic differentiation was induced. RNA was harvested at seven time points during the osteogenic differentiation period (D0, D+1, D+2, D+7, D+12, D+17 and D+21). Gene expression analysis was performed by the microarray technique and identified several differentially expressed genes. Some important genes for osteoblast differentiation had lower expression in OI patients, suggesting a smaller commitment of these patient's MSCs with the osteogenic lineage. Other genes also had their differential expression confirmed by RT-qPCR. An increase in the expression of genes related to adipocytes was observed, suggesting an increase of adipogenic differentiation at the expense osteogenic differentiation.

Orofacial findings and dental treatment in an 8-year-old patient with trisomy 18: a case report.

Trisomy 18 is characterized by: psychomotor disabilities, dysmorphic features, organ malformations, including mental retardation, growth deficiency, poor motor ability, micrognathia, microcephaly, congenital heart defects, and kidney abnormalities. The oral findings typically observed in these patients are: cleft lip and a high, narrow, and sometimes cleft palate. The degree of severity of the malformations is directly related to life expectancy. Only 5% to 10% of affected infants survive beyond the first year of life. Although trisomy 18 has been widely investigated from a medical standpoint, there is a lack of reports addressing the oral manifestations and dental treatment approach in affected children, presumably due to their shortened life expectancy. The purpose of this article was to present the case of an 8-year-old child diagnosed with trisomy 18 and address the clinical features observed--emphasizing the disease-specific oral, craniofacial, and dental findings. Dental care management of the patient is described.

[Investigation of neurodevelopment delay etiology: resources and challenges]. / Investigação das causas de atraso no neurodesenvolvimento: recursos e desafios.

To verify the reach of development delay investigation, we brought the experience in the pediatrics, infantile neurology and clinical genetics diagnoses, with resources of a tertiary health care, in 73 children, from 1 to 47 months age, between 1999 and 2001, attending a Stimulation Program of the Association of Parents and Friends of Exceptional Children of Batatais-SP. With a transversal and prospective method, six groups were identified: motor disturbances, dysmorphisms, malnutrition, macrocephaly, microcephaly and motor delay. In the analysis of the contribution of the antecedents, physical or laboratory exams to the diagnosis, it stands out the brain image in the groups "motor disturbances" and "macrocephaly"; and for the remaining groups, the physical examination and maternal data. The causes were detected in 48 (66%), being 38.4% of environmental and 24.6% genetics origin. It is emphasized the specialist evaluation, and the need of appropriate flow of information in the net of health.

Splenopancreatic field abnormality is not unique to trisomy 13.

Splenopancreatic fusion is an uncommon finding, usually only seen as part of the splenopancreatic field abnormality associated with trisomy 13. It may present itself either as ectopic splenic tissue in the cauda pancreatis, as ectopic pancreatic tissue in the spleen or accessory spleen, or as fusion of the cauda pancreatis and splenic hilum. In this study, we report four unrelated congenital anomaly cases presenting trisomy 21, osteocraniostenosis syndrome, isolated congenital heart defect, and oligohydramnios sequence due to prune belly syndrome, in which fusion was observed. This demonstrates that, although it may be more common in trisomy 13, this phenomenon should not be interpreted as pathognomonic to that syndrome.

A further case of a Prader-Willi syndrome phenotype in a patient with Angelman syndrome molecular defect.

Angelman syndrome (AS) and Prader-Willi syndrome (PWS) are distinct human neurogenetic disorders; however, a clinical overlap between AS and PWS has been identified. We report on a further case of a patient showing the PWS phenotype with the AS molecular defect. Despite the PWS phenotype, the DNA methylation analysis of SNRPN revealed an AS pattern. Cytogenetic and FISH analysis showed normal chromosomes 15 and microsatellite analysis showed heterozygous loci inside and outside the 15q11-13 region. The presence of these atypical cases could be more frequent than previously expected and we reinforce that the DNA methylation analysis is important for the correct diagnosis of severe mental deficiency, congenital hypotonia and obesity.