Nat Commun. 2020 Jul 7;11(1):3391. doi: 10.1038/s41467-020-17069-9. ABSTRACT Neurodegeneration is a common hallmark of individuals with hereditary defects in DNA single-strand break repair; a process regulated by poly(ADP-ribose) metabolism. Recently, mutations in the ARH3 (ADPRHL2) hydrolase that removes ADP-ribose from proteins have been associated with neurodegenerative disease. Here, we show that ARH3-mutated patient cells accumulate mono(ADP-ribose) scars on core histones that are a molecular memory of recently repaired DNA single-strand breaks. We demonstrate that the ADP-ribose chromatin scars result in reduced endogenous levels of important chromatin modifications such as H3K9 acetylation, and that ARH3 patient cells exhibit measurable levels of deregulated transcription. Moreover, we show that the mono(ADP-ribose) scars are lost from the chromatin of ARH3-defective cells in the prolonged presence of PARP inhibition, and concomitantly that chromatin acetylation is restored to normal. Collectively, these data indicate that ARH3 can act as an eraser of ADP-ribose chromatin scars at sites of PARP activity during DNA single-strand break repair. PMID:32636369 | PMC:PMC7341855 | DOI:10.1038/s41467-020-17069-9

Sci Rep. 2020 Jul 3;10(1):11020. doi: 10.1038/s41598-020-67656-5. ABSTRACT Rapid whole genome sequencing (rWGS) of peripheral blood has been used to detect microbial DNA in acute infections. Cytomegalovirus (CMV) is a herpesvirus capable of causing severe disease in neonates and immunocompromised patients. We identified CMV in patients undergoing diagnostic rWGS by matching reads that did not align to the human reference genome to a database of microbial genomes. rWGS was conducted on peripheral blood obtained from ill pediatric patients (age 1 day to 18 years). Reads not aligning to the human genome were analyzed using an in-house pipeline to identify DNA consistent with CMV infection. Of 669 patients who received rWGS from July 2016 through July 2019, we identified 28 patients (4.2%) with reads that aligned to the CMV reference genome. Six of these patients had clinical findings consistent with symptomatic CMV infection. Positive results were highly correlated (R² > 0.99, p < 0.001) to a CMV-qPCR assay conducted on DNA isolated from whole blood samples. In acutely ill children receiving rWGS for diagnosis of genetic disease, we propose analysis of patient genetic data to identify CMV, which could impact treatment of up to 4% of children in the intensive care unit. PMID:32620939 | PMC:PMC7335102 | DOI:10.1038/s41598-020-67656-5

BMC Neurol. 2020 Jun 16;20(1):246. doi: 10.1186/s12883-020-01798-x. ABSTRACT BACKGROUND: KMT2B-related dystonia is a recently described form of childhood onset dystonia that may improve with deep brain stimulation. Prior reports have focused on neurologic features including prominent bulbar involvement without detailing general health consequences that may result from orolingual dysfunction. We describe a family with novel KMT2B mutation with several members with failure to thrive to highlight this non-neurologic, but consequential impact of mutation in this gene. CASE PRESENTATION: We present a case of a 15-year old female who was admitted and evaluated for failure to thrive. On exam, she had severe speech dysfluency, limited ability to protrude the tongue, and generalized dystonia involving the oromandibular region, right upper and left lower extremity with left foot inversion contracture. The proband and her parents underwent whole genome sequencing. A previously undescribed variant, c.4960 T > C (p.Cys1654Arg), was identified in the KMT2B gene in the proband and mother, and this variant was subsequently confirmed in two maternal cousins, one with failure to thrive. Literature review identified frequent reports of prominent bulbar involvement but failure to thrive is rarely mentioned. CONCLUSION: Failure to thrive is a common pediatric clinical condition that has consequences for growth and development. In the presence of an abnormal neurologic exam, a search for a specific underlying genetic etiology should be pursued. With this case series, we highlight an unusual potentially treatable cause of failure to thrive, reinforce the importance of precise molecular diagnosis for patients with failure to thrive and an abnormal neurologic exam, and underscore the importance of cascade screening of family members. PMID:32546208 | PMC:PMC7296679 | DOI:10.1186/s12883-020-01798-x

Am J Med Genet C Semin Med Genet. 2020 Jun;184(2):456-468. doi: 10.1002/ajmg.c.31803. Epub 2020 Jun 17. ABSTRACT Identifying the factors related to adaptive functioning will improve the information available to families and providers of females with Trisomy X. Cognitive and behavioral features were assessed in 50 females ages 12.2 ± 3.6 years using the Behavior Assessment System for Children Second Edition (BASC-2) and Wechsler Scales of Intelligence. Executive functioning, social skills, and autistic traits were evaluated in a subset. Adaptive functioning was assessed using the BASC-2 adaptive skills composite score (ASC). Participants were classified as average adaptive skills (ASC T-score > 40) or deficits (ASC T-score < 40). Group comparisons were conducted. Multiple linear regression examined which factors contributed to ASC score. Twenty-eight females (55.6%) had adaptive skills deficits with functional communication being the most commonly affected adaptive domain. The group with ASC in the average range had higher verbal IQ (VIQ) and lower rates of numerous behavioral concerns. Internalizing behavior composite, DSM-IV inattentive symptoms score, and VIQ were significant predictors of ASC. Prenatally diagnosed females comprised over 70% of those with average adaptive skills. In this study, internalizing behaviors, inattentive ADHD symptoms, and VIQ were associated with poorer adaptive functioning. Early interventions targeting internalizing behaviors, attention/executive functioning, and communication skills may improve adaptive skills and deserve further study. PMID:32548885 | DOI:10.1002/ajmg.c.31803

J Perinatol. 2020 Jul;40(7):1007-1016. doi: 10.1038/s41372-020-0697-y. Epub 2020 May 29. ABSTRACT Genetic disorders presenting in the neonatal period can have a significant impact on morbidity and mortality. Early diagnosis can facilitate timely prognostic counseling to families and possibility of precision care, which could improve outcome. As availability of diagnostic testing expands, the required knowledge base of the neonatologist must also expand to include proper application and understanding of genetic testing modalities, especially where availability of clinical genetics consultation is limited. Herein, we review genetic tests utilized in the neonatal intensive care unit (NICU) providing background on the technology, clinical indications, advantages, and limitations of the tests. This review will span from classic cytogenetics to the evolving role of next generation sequencing and its impact on the management of neonatal disease. PMID:32472107 | DOI:10.1038/s41372-020-0697-y

Genome Med. 2020 May 27;12(1):48. doi: 10.1186/s13073-020-00748-z. ABSTRACT Clinical whole-genome sequencing (WGS) offers clear diagnostic benefits for patients with rare disease. However, there are barriers to its widespread adoption, including a lack of standards for clinical practice. The Medical Genome Initiative consortium was formed to provide practical guidance and support the development of standards for the use of clinical WGS. PMID:32460895 | PMC:PMC7254704 | DOI:10.1186/s13073-020-00748-z

Orphanet J Rare Dis. 2020 May 26;15(1):126. doi: 10.1186/s13023-020-01379-8. ABSTRACT BACKGROUND: Tetrahydrobiopterin (BH₄) deficiencies comprise a group of six rare neurometabolic disorders characterized by insufficient synthesis of the monoamine neurotransmitters dopamine and serotonin due to a disturbance of BH₄ biosynthesis or recycling. Hyperphenylalaninemia (HPA) is the first diagnostic hallmark for most BH₄ deficiencies, apart from autosomal dominant guanosine triphosphate cyclohydrolase I deficiency and sepiapterin reductase deficiency. Early supplementation of neurotransmitter precursors and where appropriate, treatment of HPA results in significant improvement of motor and cognitive function. Management approaches differ across the world and therefore these guidelines have been developed aiming to harmonize and optimize patient care. Representatives of the International Working Group on Neurotransmitter related Disorders (iNTD) developed the guidelines according to the SIGN (Scottish Intercollegiate Guidelines Network) methodology by evaluating all available evidence for the diagnosis and treatment of BH₄ deficiencies. CONCLUSION: Although the total body of evidence in the literature was mainly rated as low or very low, these consensus guidelines will help to harmonize clinical practice and to standardize and improve care for BH₄ deficient patients. PMID:32456656 | PMC:PMC7251883 | DOI:10.1186/s13023-020-01379-8

J Med Genet. 2021 Apr;58(4):237-246. doi: 10.1136/jmedgenet-2020-106849. Epub 2020 May 21. ABSTRACT BACKGROUND: Intellectual disability syndromes (IDSs) with or without developmental delays affect up to 3% of the world population. We sought to clinically and genetically characterise a novel IDS segregating in five unrelated consanguineous families. METHODS: Clinical analyses were performed for eight patients with intellectual disability (ID). Whole-exome sequencing for selected participants followed by Sanger sequencing for all available family members was completed. Identity-by-descent (IBD) mapping was carried out for patients in two Egyptian families harbouring an identical variant. RNA was extracted from blood cells of Turkish participants, followed by cDNA synthesis and real-time PCR for TTC5. RESULTS: Phenotype comparisons of patients revealed shared clinical features of moderate-to-severe ID, corpus callosum agenesis, mild ventriculomegaly, simplified gyral pattern, cerebral atrophy, delayed motor and verbal milestones and hypotonia, presenting with an IDS. Four novel homozygous variants in TTC5: c.629A>G;p.(Tyr210Cys), c.692C>T;p.(Ala231Val), c.787C>T;p.(Arg263Ter) and c.1883C>T;p.(Arg395Ter) were identified in the eight patients from participating families. IBD mapping revealed that c.787C>T;p.(Arg263Ter) is a founder variant in Egypt. Missense variants c.629A>G;p.(Tyr210Cys) and c.692C>T;p.(Ala231Val) disrupt highly conserved residues of TTC5 within the fifth and sixth tetratricopeptide repeat motifs which are required for p300 interaction, while the nonsense variants are predicted to decrease TTC5 expression. Functional analysis of variant c.1883C>T;p.(Arg395Ter) showed reduced TTC5 transcript levels in accordance with nonsense-mediated decay. CONCLUSION: Combining our clinical and molecular data with a recent case report, we identify the core and variable clinical features associated with TTC5 loss-of-function variants and reveal the requirement for TTC5 in human brain development and health. PMID:32439809 | DOI:10.1136/jmedgenet-2020-106849

Trends Neurosci. 2020 Jul;43(7):519-532. doi: 10.1016/j.tins.2020.04.009. Epub 2020 May 15. ABSTRACT Neural tube defects (NTDs) represent a failure of the neural plate to complete the developmental transition to a neural tube. NTDs are the most common birth anomaly of the CNS. Following mandatory folic acid fortification of dietary grains, a dramatic reduction in the incidence of NTDs was observed in areas where the policy was implemented, yet the genetic drivers of NTDs in humans, and the mechanisms by which folic acid prevents disease, remain disputed. Here, we discuss current understanding of human NTD genetics, recent advances regarding potential mechanisms by which folic acid might modify risk through effects on the epigenome and transcriptome, and new approaches to study refined phenotypes for a greater appreciation of the developmental and genetic causes of NTDs. PMID:32423763 | PMC:PMC7321880 | DOI:10.1016/j.tins.2020.04.009