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Genetic pleiotropy is abundant across spatially distributed brain characteristics derived from one neuroimaging modality (e.g. structural, functional or diffusion MRI). A better understanding of pleiotropy across modalities could inform us on the integration of brain function, micro- and macrostructure. Here we show extensive genetic overlap across neuroimaging modalities at a locus and gene level in the UK Biobank (N=34,029) and ABCD study (N=8,607). When jointly analysing phenotypes derived from structural, functional and diffusion MRI with the Multivariate Omnibus Statistical Test (MOSTest) method, we boost the discovery of loci and genes associated with brain features beyond previously identified effects for each modality individually. Cross-modality genes are involved in fundamental biological processes and predominantly expressed during prenatal brain development. We additionally boost genetic discovery for psychiatric disorders by conditioning independent GWAS on our multimodal multivariate GWAS. These findings shed light on the shared genetic mechanisms underlying variation in brain morphology, functional connectivity, and tissue composition – features often concurrently altered within psychiatric disorders.Graphical abstract

Introduction Menke-Hennekam syndrome (MHS) is a relatively new genetic condition characterized by intellectual disabilities, autistic behavior, auditory defects, recurrent upper respiratory tract infections, microcephaly and short stature. Facial characteristics include short palpebral fissures, telecanthus, depressed nasal bridge, short nose, anteverted nares, short columella, and long philtrum. The genetic defect is represented by missense variants of CREBBP gene, located on exons 30 or 31. There are only around 30 cases reported by now. Objectives The aim of the paper is to report a new case of MHS. Methods The case is a 3-year-old boy admitted in our department for developmental delay. The clinical examination revealed dysmorphic features; severe speech delay, mild intellectual disability, autistic behaviour.The patient had a personal history of recurrent respiratory infections, visual defect and bilateral sensorineural hearing loss. Other investigations included EEG, abdominal echography, and cerebral MRI all were normal. The genetic studies included array CGH and WES. Results The array CGH was normal. WES identified a pathogenic heterozygote variant c.5600G>A in the exon 31 of CREBBP gene, confirming MHS. Conclusions Overall, the features of our patient are consistent with those reported in the previous reports, including developmental and speech delay, autistic behavior, dysmorphic features, recurrent upper way infections, sensorineural hearing loss, and visual defects. Other common features, such as growth delay and microcephaly were not present in our patient. Our case contributes to the clinical characterisation of the new syndrome. Funding: The research leading to these results has received funding from the EEA Grant 2014-2021, under the project contract No 6/2019. Disclosure No significant relationships.

Introduction Background: Copy-number variants (CNVs) of chromosome 15 have been associated with neurodevelopmental disorders like autism spectrum disorders (ASDs) and developmental delay. Objectives We report 6 patients with autistic features and other neurodevelopmental problems carrying CNVs of chromosome 15. Methods Materials and methods: The probands belong to a group of patients referred to our clinic and laboratory with autism as main feature. A complete clinical evaluation was performed with focus on neurologic, psychiatric, and psychological evaluation with specific autism tests. Array-based comparative genomic hybridization (array-CGH) was performed using 180K platform (Agilent technology). Results six patients investigated by array-CGH had a CNV involving chromosome 15. Four of these patients, previously reported by us (ref 1), had small duplications of 15q13.3 involving CHRNA7 and OTUD7A genes. The other two patients had large deletions of 15q21q22 and 15q24, respectively. A deletion of 15q21.2 - q22.2 was detected in one patient. The deleted region contains 62 genes and has been rarely reported in patients with neurodevelopmental disorders. A deletion of 15q24.1 - q24.2 was detected in the other patient. This region is recurrently deleted in developmentally delayed patients (ref 3). Conclusions Our data highlight that chromosome 15 is a hub for neurodevelopmental disorder and illustrates the utility of array-CGH in the investigation of patients with autism, specifically in the context of complex phenotypes. Acknowledgment: The research leading to these results has received funding from the EEA Grant 2014-2021, under the project contract No 6/2019. References: Genes (Basel). 2021 Jul 1;12(7):1025. https://www.omim.org/entry/618060 Clinical Genome Resource. https://dosage.clinicalgenome.org/clingen_region.cgi?id=ISCA-46296 Disclosure No significant relationships.

Floating-Harbor syndrome (FHS) is a rare autosomal dominant syndrome characterized by short stature with delayed bone age, retarded speech development, intellectual disability and dysmorphic facial features. Recently, dominant mutations almost exclusively clustered in the final exon of the Snf2-related CREBBP activator protein (SRCAP) gene were identified to cause FHS. Here, we report a boy with short stature, speech delay, mild intellectual disability, dysmorphic features, and with genetically confirmed FHS. To the best of our knowledge, this is the first molecularly confirmed case with this syndrome reported in Romania. An intensive program of cognitive and speech stimulation, as well as yearly neurological, psychological, ophthalmological, otorhinolaryngological, pediatric and endocrinological monitoring for our patient were designed. We propose a checklist of clinical features suggestive of FHS, based on the main clinical features, in order to facilitate the diagnosis and clinical management of this rare condition.

IntroductionBrain heterotopia represent a group of rare malformations with a heterogeneous phenotype, ranging from asymptomatic to severe clinical picture (resistant epilepsy, severe developmental delay). The etiology is multifactorial, including both genetic and environmental factors.ObjectivesIn this paper we present our experience regarding behavior problems in patients with heterotopia.MethodsA cohort of 16 pediatric patients with brain heterotopia, six females and ten males, with age at last follow-up ranging from 2 months to 24 years were investigated by clinical examination, electroencephalographic studies, brain imaging, and genomic tests. Specific psychological tests and psychiatric evaluation were performed in all children for behavior problems assessment.ResultsSix individuals presented behavioral problems: autism (three patients) and hyperkinesia with attention deficit (three patients). All of them had intellectual disability or learning problems; five patients had epilepsy, with drug-resistant seizures in four cases. In two cases the behavioral problems occurred before the onset of epileptic seizures.ConclusionsBehavior problems are important features in patients with brain heterotopia, making the management of these patients more difficult, especially when they occur in association with drug-resistant epilepsy. Acknowledgements: This work was supported partially by grants of the Romanian National Authority for Scientific Research and Innovation CCCDI – UEFISCDI, Projects COFUND-ERANET E-RARE 3-HETER-OMICS-2 Number 87/2019 and 88/2019 within PNCDI III.DisclosureNo significant relationships.

Chromosome Y Isodicentrics in two Cases with Ambiguous genitalia and Features of Turner SyndromeKaryotype investigations using classical cytogenetics, fluorescencein situhybridization (FISH) and polymerase chain reaction (PCR) techniques were used for the characterization of Y chromosome structural anomalies found in two patients with ambiguous genitalia and features of Turner syndrome. Both exhibited mosaic karyotypes of peripheral blood lymphocytes. The karyotype was 45, X[90]/ 46, X, idic(Y)(p11.3).ish idic(Y) (wcpY+, DXYS130++,SRY++,DYZ3++,DYZ1++, DYS224++)[10] in one case, and the karyotype was 45, X[65]/46, X, idic(Y) (q11).ish idic(Y)(SRY++, RP11-140H23-)[35] in the other case. Derivative Y chromosomes were different in shape and size and positive for the SRY gene, a common underlying element of ambiguous genitalia phenotypes. These results add new information concerning the role of Y chromosome structural abnormalities in sex determination pathway perturbation which are poorly understood, and highlight the importance of the sex chromosomes integrity for a normal sex phenotype development.