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The membrane-bound O-acyltransferase domain-containing 7 (MBOAT7) protein is an acyltransferase catalyzing arachidonic acid incorporation into lysophosphatidylinositol. Patients with rare, biallelic loss-of-function variants of the MBOAT7 gene display intellectual disability with neurodevelopmental defects. The rs641738 inherited variant associated with reduced hepatic MBOAT7 expression has been linked to steatotic liver disease susceptibility. However, the impact of biallelic loss-of-function MBOAT7 variants on liver disease is not known. We report on a 2-year-old girl with MBOAT7 -related intellectual disability and steatotic liver disease, confirming that MBOAT7 loss-of-function predisposes to liver disease.

KBG syndrome (KBGS) is characterized by distinctive facial gestalt, short stature and variable clinical findings. With ageing, some features become more recognizable, allowing a differential diagnosis. We aimed to better characterize natural history of KBGS. In the context of a European collaborative study, we collected the largest cohort of KBGS patients (49). A combined array- based Comparative Genomic Hybridization and next generation sequencing (NGS) approach investigated both genomic Copy Number Variants and SNVs. Intellectual disability (ID) (82%) ranged from mild to moderate with severe ID identified in two patients. Epilepsy was present in 26.5%. Short stature was consistent over time, while occipitofrontal circumference (median value: -0.88 SD at birth) normalized over years. Cerebral anomalies, were identified in 56% of patients and thus represented the second most relevant clinical feature reinforcing clinical suspicion in the paediatric age when short stature and vertebral/dental anomalies are vague. Macrodontia, oligodontia and dental agenesis (53%) were almost as frequent as skeletal anomalies, such as brachydactyly, short fifth finger, fifth finger clinodactyly, pectus excavatum/carinatum, delayed bone age. In 28.5% of individuals, prenatal ultrasound anomalies were reported. Except for three splicing variants, leading to a premature termination, variants were almost all frameshift. Our results, broadening the spectrum of KBGS phenotype progression, provide useful tools to facilitate differential diagnosis and improve clinical management. We suggest to consider a wider range of dental anomalies before excluding diagnosis and to perform a careful odontoiatric/ear-nose-throat (ENT) evaluation in order to look for even submucosal palate cleft given the high percentage of palate abnormalities. NGS approaches, following evidence of antenatal ultrasound anomalies, should include ANKRD11., (© The Author(s) 2022. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Intellectual disability (ID) is characterized by impairments in the cognitive processes and in the tasks of daily life. It encompasses a clinically and genetically heterogeneous group of neurodevelopmental disorders often associated with autism spectrum disorder (ASD). Social and communication abilities are strongly compromised in ASD. The prevalence of ID/ASD is 1-3%, and approximately 30% of the patients remain without a molecular diagnosis. Considering the extreme genetic locus heterogeneity, next-generation sequencing approaches have provided powerful tools for candidate gene identification. Molecular diagnosis is crucial to improve outcome, prevent complications, and hopefully start a therapeutic approach. Here, we performed parent-offspring trio whole-exome sequencing (WES) in a cohort of 60 mostly syndromic ID/ASD patients and we detected 8 pathogenic variants in genes already known to be associated with ID/ASD ( SYNGAP1 , SMAD6 , PACS1 , SHANK3 , KMT2A , KCNQ2 , ACTB , and POGZ) . We found four de novo disruptive variants of four novel candidate ASD/ID genes: MBP , PCDHA1 , PCDH15 , PDPR . We additionally selected via bioinformatic tools many variants in unknown genes that alone or in combination can contribute to the phenotype. In conclusion, our data confirm the efficacy of WES in detecting pathogenic variants of known and novel ID/ASD genes.

Nicolaides-Baraitser syndrome (NCBRS), caused by a mutation in the SMARCA2 gene, which goes along with intellectual disability, congenital malformations, especially of face and limbs, and often difficult-to-treat epilepsy, is surveyed focusing on epilepsy and its treatment. Patients were recruited via "Network Therapy of Rare Epilepsies (NETRE)" and an international NCBRS parent support group. Inclusion criterion is NCBRS-defining SMARCA2 mutation. Clinical findings including epilepsy classification, anticonvulsive treatment, electroencephalogram (EEG) findings, and neurodevelopmental outcome were collected with an electronic questionnaire. Inclusion of 25 NCBRS patients with epilepsy in 23 of 25. Overall, 85% of the participants (17/20) reported generalized seizures, the semiology varied widely. EEG showed generalized epileptogenic abnormalities in 53% (9/17), cranial magnetic resonance imaging (cMRI) was mainly inconspicuous. The five most frequently used anticonvulsive drugs were valproic acid (VPA [12/20]), levetiracetam (LEV [12/20]), phenobarbital (PB [8/20]), topiramate (TPM [5/20]), and carbamazepine (CBZ [5/20]). LEV (9/12), PB (6/8), TPM (4/5), and VPA (9/12) reduced the seizures' frequency in more than 50%. Temporary freedom of seizures (>6 months) was reached with LEV (4/12), PB (3/8), TPM (1/5, only combined with PB and nitrazepam [NZP]), and VPA (4/12). Seizures aggravation was observed under lamotrigine (LTG [2/4]), LEV (1/12), PB (1/8), and VPA (1/12). Ketogenic diet (KD) and vagal nerve stimulation (VNS) reduced seizures' frequency in one of two each. This first worldwide retrospective analysis of anticonvulsive therapy in NCBRS helps to treat epilepsy in NCBRS that mostly shows only initial response to anticonvulsive therapy, especially with LEV and VPA, but very rarely shows complete freedom of seizures in this, rather genetic than structural epilepsy., Competing Interests: None declared., (Thieme. All rights reserved.)

Purpose: To determine whether duplication of the ARID1A gene is responsible for a new recognizable syndrome., Methods: We describe four patients with a 1p36.11 microduplication involving ARID1A as identified by array-comparative genomic hybridization . We performed comparative transcriptomic analysis of patient-derived fibroblasts using RNA sequencing and evaluated the impact of ARID1A duplication on the cell cycle using fluorescence-activated cell sorting. Functional relationships between differentially expressed genes were investigated with ingenuity pathway analysis (IPA)., Results: Combining the genomic data, we defined a small (122 kb), minimally critical region that overlaps the full ARID1A gene. The four patients shared a strikingly similar phenotype that included intellectual disability and microcephaly. Transcriptomic analysis revealed the deregulated expression of several genes previously linked to microcephaly and developmental disorders as well as the involvement of signaling pathways relevant to microcephaly, among which the polo-like kinase (PLK) pathway was especially notable. Cell-cycle analysis of patient-derived fibroblasts showed a significant increase in the proportion of cells in G1 phase at the expense of G2-M cells., Conclusion: Our study reports a new microduplication syndrome involving the ARID1A gene. This work is the first step in clarifying the pathophysiological mechanism that links changes in the gene dosage of ARID1A with intellectual disability and microcephaly.Genet Med advance online publication 01 December 2016.

Background: Nicolaides-Baraitser and Coffin-Siris syndromes are emerging conditions with overlapping clinical features including intellectual disability and typical somatic characteristics, especially sparse hair, low frontal hairline, large mouth with thick and everted lips, and hands and feet anomalies. Since 2012, mutations in genes encoding six proteins of the BAF complex were identified in both conditions., Methods and Results: We have clinically evaluated a cohort of 1161 patients with intellectual disability from three different Italian centers. A strong clinical suspicion of either Nicolaides-Baraitser syndrome or Coffin-Siris syndrome was proposed in 11 cases who were then molecularly confirmed: 8 having de novo missense mutations in SMARCA2, two frame-shift mutations in ARID1B and one missense mutation in SMARCB1. Given the high frequency of the condition we set up a one-step deep sequencing test for all 6 genes of the BAF complex., Conclusions: These results prove that the frequency of these conditions may be as high as the most common syndromes with intellectual deficit (about 1%). Clinical geneticists should be well aware of this group of disorders in the clinical setting when ascertaining patients with intellectual deficit, the specific facial features being the major diagnostic handle. Finally, this work adds information on the clinical differences of the two conditions and presents a fast and sensitive test for the molecular diagnosis., (Copyright © 2014 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)