Fetal agenesis of the corpus callosum: Clinical and genetic analysis in a series of 40 patients.

OBJECTIVES: This study aimed to explore the genetic causes of agenesis of the corpus callosum (ACC) and assess the utility of karyotype analysis, copy number variation sequencing (CNV-seq), and whole-exome sequencing (WES) to genetically diagnose fetal ACC. METHODS: We retrospectively examined 40 fetuses diagnosed with ACC who underwent prenatal ultrasonography or magnetic resonance imaging between January 2019 and October 2023. Genetic tests were conducted on the fetuses using karyotype analysis or CNV-seq as the first-line diagnosis. WES was performed if aneuploid and pathogenic CNVs were excluded. RESULTS: Among the 40 fetuses, 29 (72 %) had non-isolated ACC and 11 (28 %) had isolated ACC. Cerebellar dysplasia and hydrocephalus were the most common abnormal developments in the central nervous system. Twenty-eight patients underwent karyotype analysis, with a detection rate of 14 % (4/28). Twenty-six patients underwent CNV-seq; three patients were found to have pathogenic CNVs, with a detection rate of 12 % (3/26). Thirty-three fetuses with no findings of karyotype analysis or CNV-seq were subsequently tested using WES, with a detection rate of 36 % (12/33). Overall, the total diagnostic yield was 48 % (19/40), and monogenic etiology accounted for 30 % (12/40). The genetic detection rate of fetal non-isolated ACC (62 %, 18/29) was higher than that of isolated ACC (9 %, 1/11). CONCLUSION: Prenatal genetic analysis of fetuses with ACC is clinically significant, with monogenic disorders being the main cause. WES may enhance the detection rate of fetuses with ACC with negative karyotype analysis or CNV-seq results.

Imaginative elaboration in agenesis of the corpus callosum: topic modeling and perplexity.

OBJECTIVE: Previous studies have found deficits in imaginative elaboration and social inference to be associated with agenesis of the corpus callosum (ACC; Renteria-Vasquez et al., 2022; Turk et al., 2009). In the current study, Thematic Apperception Test (TAT) responses from a neurotypical control group and a group of individuals with ACC were used to further study the capacity for imaginative elaboration and story coherence. METHOD: Topic modeling was employed utilizing Latent Diritchlet Allocation to characterize the narrative responses to the pictures used in the TAT. A measure of the difference between models (perplexity) was used to compare the topics of the responses of individual participants to the common core model derived from the responses of the control group. Story coherence was tested using sentence-to-sentence Latent Semantic Analysis. RESULTS: Group differences in perplexity were statistically significant overall, and for each card individually (p < .001). There were no differences between the groups in story coherence. CONCLUSIONS: TAT narratives from persons with ACC were normally coherent, but more conventional (i.e., more similar to the core text) compared to those of neurotypical controls. Individuals with ACC can make conventional social inferences about socially ambiguous stimuli, but are restricted in their imaginative elaborations, resulting in less topical variability (lower perplexity values) compared to neurotypical controls.

Association of limited dorsal myeloschizis and corpus callosum lipoma: A case report and literature review.

Background: Intracranial lipomas are a rare clinical entity. These lesions are frequently asymptomatic and originate in the pericallosal area. As they are fat-containing lesions which are intimately attached to the surrounding structures, surgery is not recommended. In some individual reports, subtotal resection is recommended to lessen complications. There have been no previous reports of corpus callosum lipoma (CCL) associated with limited dorsal myeloschizis (LDM). Case Description: We describe the case of a combination of CCL and bilateral choroid plexus lipoma discovered incidentally during the investigation of LDM in a 3-month-old male child. Given the asymptomatic behavior of the lipoma and the vascular elements of the pericallosal area, it was decided to monitor it regularly. Thus, the patient underwent surgery only for LDM. Histological examination confirmed the diagnosis, and postoperative follow-up 1 year after showed good evolution. To the best of our knowledge, this association has never been described in the literature. Conclusion: This case suggests a possible developmental relationship between CCL and spinal dysraphism.

Dmd mdx mice have defective oligodendrogenesis, delayed myelin compaction and persistent hypomyelination.

Duchenne muscular dystrophy (DMD) is caused by mutations in the DMD gene, resulting in the loss of dystrophin, a large cytosolic protein that links the cytoskeleton to extracellular matrix receptors in skeletal muscle. Aside from progressive muscle damage, many patients with DMD also have neurological deficits of unknown etiology. To investigate potential mechanisms for DMD neurological deficits, we assessed postnatal oligodendrogenesis and myelination in the Dmdmdx mouse model. In the ventricular-subventricular zone (V-SVZ) stem cell niche, we found that oligodendrocyte progenitor cell (OPC) production was deficient, with reduced OPC densities and proliferation, despite a normal stem cell niche organization. In the Dmdmdx corpus callosum, a large white matter tract adjacent to the V-SVZ, we also observed reduced OPC proliferation and fewer oligodendrocytes. Transmission electron microscopy further revealed significantly thinner myelin, an increased number of abnormal myelin structures and delayed myelin compaction, with hypomyelination persisting into adulthood. Our findings reveal alterations in oligodendrocyte development and myelination that support the hypothesis that changes in diffusion tensor imaging seen in patients with DMD reflect developmental changes in myelin architecture.

ARID1B controls transcriptional programs of axon projection in an organoid model of the human corpus callosum.

Mutations in ARID1B, a member of the mSWI/SNF complex, cause severe neurodevelopmental phenotypes with elusive mechanisms in humans. The most common structural abnormality in the brain of ARID1B patients is agenesis of the corpus callosum (ACC), characterized by the absence of an interhemispheric white matter tract that connects distant cortical regions. Here, we find that neurons expressing SATB2, a determinant of callosal projection neuron (CPN) identity, show impaired maturation in ARID1B+/- neural organoids. Molecularly, a reduction in chromatin accessibility of genomic regions targeted by TCF-like, NFI-like, and ARID-like transcription factors drives the differential expression of genes required for corpus callosum (CC) development. Through an in vitro model of the CC tract, we demonstrate that this transcriptional dysregulation impairs the formation of long-range axonal projections, causing structural underconnectivity. Our study uncovers new functions of the mSWI/SNF during human corticogenesis, identifying cell-autonomous axonogenesis defects in SATB2+ neurons as a cause of ACC in ARID1B patients.

Identifying Lesions of the Corpus Callosum in Patients With Neurofibromatosis Type 1.

BACKGROUND: Neurofibromatosis type 1 (NF1) is a multisystemic autosomal dominant disorder that includes intracranial lesions such as unidentified bright objects (UBOs)-areas of increased T2 signal on magnetic resonance imaging (MRI)-and tumors known as gliomas. The presence of these lesions in the corpus callosum (CC) has not been previously studied in a large cohort. METHODS: We reviewed medical records of 681 patients (aged three months to 86 years) followed at our institution from 2000 to 2023 with NF1 and one or more brain MRI. Patients with lesions in the CC were identified, and RAPNO/RANO criteria were used to determine changes in size over time, where a change of 25% in the product of perpendicular measurements indicates growth or shrinkage. RESULTS: Forty-seven patients had CC UBOs, most of which were in the splenium (66.0%). Seventeen patients had CC gliomas (10% of those with any glioma), two of whom had two gliomas. Seventeen of 19 gliomas were in the splenium. Over follow-up, eight of 19 remained stable, three shrunk, and eight grew. The mean percentage change in the product of the dimensions was 311.5% (ranging from -46.7% to 2566.6%). Of the eight lesions that grew, one required treatment. CONCLUSIONS: There is a 6.9% and 2.5% prevalence of CC UBOs and gliomas, respectively, in our cohort of patients with NF1. Most lesions are present in the splenium, and although some gliomas demonstrate significant growth, they rarely require treatment. This work is the largest series of CC lesions in NF1 and adds to the growing data to inform appropriate follow-up.

Greater methylation of the IL-6 promoter region is associated with decreased integrity of the corpus callosum in schizophrenia.

BACKGROUND: Schizophrenia is associated with chronic subclinical inflammation and decreased integrity of the corpus callosum (CC). Our previous study showed associations between peripheral IL-6 levels and the integrity of the CC. Epigenetic studies show associations between methylation of the genes related to immunological processes and integrity of the CC. AIM: To investigate correlations between methylation status of IL-6 promotor and peripheral IL-6 levels and the integrity of the CC in schizophrenia. MATERIAL AND METHODS: The participants were 29 chronic schizophrenia patients (SCH) and 29 controls. Decreased integrity of the CC was understood as increased mean diffusivity (MD) and/or decreased fractional anisotropy (FA) in diffusion tensor imaging. Peripheral IL-6 concentrations were measured in serum samples and IL-6 promoter methylation status of 6 CpG sites was analyzed in peripheral leukocytes by pyrosequencing. RESULTS: Moderate positive correlations were found between CpG1 methylation and the MD of proximal regions of the CC (CCR1-CCR3) and between CpGmean and MD of CCR1 in SCH. Weaker positive correlations were found for CpGmean with CCR2 and CCR3 and negative correlations were found for CpG1 and FA of CCR3 in SCH. Multivariate regression showed that methylation of CpG1, type of antipsychotic treatment, and their interaction were significant independent predictors of MD of CCR1 in SCH. Methylation of CpG2 was negatively correlated with serum IL-6 in SCH. CONCLUSIONS: The methylation level of the IL-6 promotor region in peripheral leukocytes is associated with the integrity of the CC in schizophrenia and this association may depend on the type of antipsychotic treatment. Further studies are necessary to explain the mechanisms of the observed associations.

Genetic etiology of agenesis of the corpus callosum: a retrospective single-center cohort analysis of 114 fetuses.

PURPOSE: The identification and prognosis of the agenesis of the corpus callosum (ACC) for prenatal consultation are complex and currently unclear. This study aims to explore the correlated genetic mutations of prenatal ACC. METHODS: We retrospectively analyzed 114 prenatal cases of ACC. All cases (n = 114) were subjected to chromosomal microarray analysis (CMA), and 66 CMA-negative cases underwent prenatal exome sequencing (pES) for further analysis. RESULTS: CMA was diagnosed positively in 15/114 (13.2%) cases and pES was diagnosed positively in 24/66 (36.4%) CMA-negative cases. The detection rate of genetic causes between complete and partial ACCs was not significantly different (P > 0.05). Between isolated and non-isolated (other anomalies present) ACCs, the diagnostic rate of pES in non-isolated cases was significantly higher (P < 0.001), while CMA results did not differ (P > 0.05). The diagnostic rate of CMA was significantly increased in cases combined with intracranial and extracranial malformations (P = 0.014), while no CMA positivity was detected in cases combined with only intracranial malformations. CONCLUSION: For fetuses with prenatal ACC, further pES analysis should be recommended after negative CMA results. Chromosome abnormalities are less likely to occur when ACC with only intracranial malformations combined.

Interhemispheric coherence of EEG rhythms in children: Maturation and differentiation in corpus callosum dysgenesis.

OBJECTIVES: To evaluate the evolution of interhemispheric coherences (ICo) in background and spindle frequency bands during childhood and use it to identify individuals with corpus callosum dysgenesis (CCd). METHODS: A monocentric cohort of children aged from 0.25 to 15 years old, consisting of 13 children with CCd and 164 without, was analyzed. The ICo of background activity (ICOBckgrdA), sleep spindles (ICOspindles), and their sum (sICO) were calculated. The impact of age, gender, and CC status on the ICo was evaluated, and the sICO was used to discriminate children with or without CCd. RESULTS: ICOBckgrdA, ICOspindles and sICO increased significantly with age without any effect of gender (p < 10-4), in both groups. The regression equations of the different ICo were stronger, with adjusted R2 values of 0.54, 0.35, and 0.57, respectively. The ICo was lower in children with CCd compared to those without CCd (p < 10-4 for all comparisons). The area under the precision recall curves for predicting CCd using sICO was 0.992 with 98.9 % sensitivity and 87.5 % specificity. DISCUSSION: ICo of spindles and background activity evolve in parallel to brain maturation and depends on the integrity of the corpus callosum. sICO could be an effective diagnostic biomarker for screening children with interhemispheric dysfunction.

Differential Effects of Aging on Regional Corpus Callosum Microstructure and the Modifying Influence of Pulse Pressure.

The corpus callosum is composed of several subregions, distinct in cellular and functional organization. This organization scheme may render these subregions differentially vulnerable to the aging process. Callosal integrity may be further compromised by cardiovascular risk factors, which negatively influence white matter health. Here, we test for heterochronicity of aging, hypothesizing an anteroposterior gradient of vulnerability to aging that may be altered by the effects of cardiovascular health. In 174 healthy adults across the adult lifespan (mean age = 53.56 ± 18.90; range, 20-94 years old, 58.62% women), pulse pressure (calculated as participant's systolic minus diastolic blood pressure) was assessed to determine cardiovascular risk. A deterministic tractography approach via diffusion-weighted imaging was utilized to extract fractional anisotropy (FA), radial diffusivity (RD), and axial diffusivity (AD) from each of five callosal subregions, serving as estimates of microstructural health. General linear models tested the effects of age, hypertension, and pulse pressure on these cross-sectional metrics. We observed no significant effect of hypertensive diagnosis on callosal microstructure. We found a significant main effect of age and an age-pulse pressure interaction whereby older age and elevated pulse pressure were associated with poorer FA, AD, and RD. Age effects revealed nonlinear components and occurred along an anteroposterior gradient of severity in the callosum. This gradient disappeared when pulse pressure was considered. These results indicate that age-related deterioration across the callosum is regionally variable and that pulse pressure, a proxy of arterial stiffness, exacerbates this aging pattern in a large lifespan cohort.

Segmental Agenesis of the Corpus Callosum With Pituitary Hypoplasia.

We report a 3-year-old male with findings of segmental agenesis of the corpus callosum, pituitary hypoplasia, and Chiari I malformation. The patient was born at 33 weeks and spent five weeks in the NICU for hypoglycemia, hypotension, and dyspnea. In infancy, the patient passed an adrenocorticotropic hormone stimulation test, while cortisol, growth hormone, and insulin-like growth factor levels were within reference range. Following height and weight percentile regression the patient underwent arginine and clonidine stimulation testing at 3 years of age, prompting pituitary evaluation via MRI. The results provided exemplary neuroimaging of segmental callosal agenesis, in which the genu and splenium form despite the absence of the callosal body. This finding adds support to a newer theory of embryological callosal development where progression does not occur linearly in the rosto-caudal direction.

The Associations Between Serum Insulin-like Growth Factor-I, Brain White Matter Volumes, and Cognition in Mild Cognitive Impairment and Alzheimer's Disease.

Background: Insulin-like growth factor-I (IGF-I) regulates myelin, but little is known whether IGF-I associates with white matter functions in subjective and objective mild cognitive impairment (SCI/MCI) or Alzheimer's disease (AD). Objective: To explore whether serum IGF-I is associated with magnetic resonance imaging - estimated brain white matter volumes or cognitive functions. Methods: In a prospective study of SCI/MCI (n = 106) and AD (n = 59), we evaluated the volumes of the total white matter, corpus callosum (CC), and white matter hyperintensities (WMHs) as well as Mini-Mental State Examination (MMSE), Trail Making Test A and B (TMT-A/B), and Stroop tests I-III at baseline, and after 2 years. Results: IGF-I was comparable in SCI/MCI and AD (113 versus 118 ng/mL, p = 0.44). In SCI/MCI patients, the correlations between higher baseline IGF-I and greater baseline and 2-year volumes of the total white matter and total CC lost statistical significance after adjustment for intracranial volume and other covariates. However, after adjustment for covariates, higher baseline IGF-I correlated with better baseline scores of MMSE and Stroop test II in SCI/MCI and with better baseline results of TMT-B and Stroop test I in AD. IGF-I did not correlate with WMH volumes or changes in any of the variables. Conclusions: Both in SCI/MCI and AD, higher IGF-I was associated with better attention/executive functions at baseline after adjustment for covariates. Furthermore, the baseline associations between IGF-I and neuropsychological test results in AD may argue against significant IGF-I resistance in the AD brain.

Deciphering seizure semiology in corpus callosum injuries: A comprehensive systematic review with machine learning insights.

INTRODUCTION: Seizure disorders have often been found to be associated with corpus callosum injuries, but in most cases, they remain undiagnosed. Understanding the clinical, electrographic, and neuroradiological alternations can be crucial in delineating this entity. OBJECTIVE: This systematic review aims to analyze the effects of corpus callosum injuries on seizure semiology, providing insights into the neuroscientific and clinical implications of such injuries. METHODS: Adhering to the PRISMA guidelines, a comprehensive search across multiple databases, including PubMed/Medline, NIH, Embase, Cochrane Library, and Cross-ref, was conducted until September 25, 2023. Studies on seizures associated with corpus callosum injuries, excluding other cortical or sub-cortical involvements, were included. Machine learning (Random Forest) and deep learning (1D-CNN) algorithms were employed for data classification. RESULTS: Initially, 1250 articles were identified from the mentioned databases, and additional 350 were found through other relevant sources. Out of all these articles, 41 studies met the inclusion criteria, collectively encompassing 56 patients The most frequent clinical manifestations included generalized tonic-clonic seizures, complex partial seizures, and focal seizures. The most common callosal injuries were related to reversible splenial lesion syndrome and cytotoxic lesions. Machine learning and deep learning analyses revealed significant correlations between seizure types, semiological parameters, and callosal injury locations. Complete recovery was reported in the majority of patients post-treatment. CONCLUSION: Corpus callosum injuries have diverse impacts on seizure semiology. This review highlights the importance of understanding the role of the corpus callosum in seizure propagation and manifestation. The findings emphasize the need for targeted diagnostic and therapeutic strategies in managing seizures associated with callosal injuries. Future research should focus on expanding the data pool and exploring the underlying mechanisms in greater detail.

Single-cell approaches define two groups of mammalian oligodendrocyte precursor cells and their evolution over developmental time.

Here, we used single-cell RNA sequencing (scRNA-seq), single-cell ATAC sequencing (scATAC-seq), and single-cell spatial transcriptomics to characterize murine cortical OPCs throughout postnatal life. During development, we identified two groups of differentially localized PDGFRα+ OPCs that are transcriptionally and epigenetically distinct. One group (active, or actOPCs) is metabolically active and enriched in white matter. The second (homeostatic, or hOPCs) is less active, enriched in gray matter, and predicted to derive from actOPCs. In adulthood, these two groups are transcriptionally but not epigenetically distinct, and relative to developing OPCs are less active metabolically and have less open chromatin. When adult oligodendrogenesis is enhanced during experimentally induced remyelination, adult OPCs do not reacquire a developmental open chromatin state, and the oligodendrogenesis trajectory is distinct from that seen neonatally. These data suggest that there are two OPC groups subserving distinct postnatal functions and that neonatal and adult OPC-mediated oligodendrogenesis are fundamentally different.

Mri findings, looking behaviour and affect recognition in very preterm children: A pilot study.

Children born very preterm often exhibit atypical gaze behaviors, affect recognition difficulties and are at risk for cerebral white matter damage. This study explored links between these sequalae. In 24 12-year-old children born very preterm, ventricle size using Evans and posterior ventricle indices, and corpus callosum area were used to measure white matter thickness. The findings revealed a correlation between less attention towards the eyes and larger ventricle size. Ventricle and posterior corpus callosum sizes were correlated to affect-recognition proficiency. Findings suggest a link between white matter damage, gaze behavior, and affect recognition accuracy, emphasizing a relation with social perception.

Evidence of brain injury in fetuses of mothers with preterm labor with intact membranes and preterm prelabor rupture of membranes.

BACKGROUND: Brain injury and poor neurodevelopment have consistently been reported in infants and adults born preterm. These changes occur at least in part prenatally and are associated with intra-amniotic inflammation. The pattern of brain changes has been partially documented by magnetic resonance imaging but not with neurosonography in combination with amniotic fluid brain injury biomarkers. OBJECTIVES: To evaluate the prenatal features of brain remodeling and injury in fetuses from patients with preterm labor with intact membranes or preterm prelabor rupture of membranes and to investigate the potential influence of intra-amniotic inflammation as a mediator of risk. STUDY DESIGN: In this prospective cohort study, fetal brain remodeling and injury was evaluated by neurosonography and amniocentesis in singleton pregnant patients with preterm labor with intact membranes or preterm prelabor rupture of membranes between 24.0-34.0 weeks, with (n=41) and without (n=54) intra-amniotic inflammation. Controls for neurosonography were outpatient pregnant patients without preterm labor or preterm prelabor rupture of membranes matched 2:1 by gestational age at ultrasound. Amniotic fluid controls were patients with an amniocentesis performed for indications other than preterm labor or preterm prelabor rupture of membranes without brain or genetic defects whose amniotic fluid was collected in our biobank for research purposes matched by gestational age at amniocentesis. The group with intra-amniotic inflammation included those with intra-amniotic infection (microbial invasion of the amniotic cavity and intra-amniotic inflammation) and those with sterile inflammation. Microbial invasion of the amniotic cavity was defined as a positive amniotic fluid culture and/or positive 16S ribosomal RNA gene. Inflammation was defined by amniotic fluid interleukin-6 >13.4 ng/ml in preterm labor and >1.43 ng/ml in preterm prelabor rupture of membranes. Neurosonography included the evaluation of brain structure biometric parameters and cortical development. As amniotic fluid brain injury biomarkers we selected neuron-specific enolase, protein S100B and glial fibrillary acidic protein. Data was adjusted for cephalic biometrics, fetal growth centile, fetal sex, non-cephalic presentation and preterm prelabor rupture of membranes at admission. RESULTS: Fetuses from mothers with preterm labor with intact membranes or preterm prelabor rupture of membranes had signs of brain remodeling and injury. First, they had a smaller cerebellum. Thus, in intra-amniotic inflammation, non- intra-amniotic inflammation and control groups, transcerebellar diameter (median (25th; 75th percentile)) was 32.7mm (29.8; 37.6), 35.3mm (31.2;39.6) and 35.0mm (31.3;38.3), respectively (p=0.019); vermian height was 16.9 mm (15.5 ;19.6), 17.2 mm (16.0;18.9) and 17.1mm (15.7;19.0), respectively (p=0.041). Second, they presented a lower corpus callosum area (0.72mm2 (0.59;0. 81), 0.71mm2 (0.63;0.82) and 0.78mm2 (0.71;0. 91), respectively (p=0.006). Third, they showed a delayed cortical maturation (Sylvian fissure depth / biparietal diameter ratio was 0.14 (0.12;0.16), 0.14 (0.13;0.16) and 0.16 (0.15;0.17), respectively (p<0.001), and right parieto-occipital sulci depth ratio was 0.09 (0.07;0.12), 0.11 (0.09;0.14) and 0.11 (0.09;0.14), respectively (p=0.012)). Finally, regarding amniotic fluid brain injury biomarkers, fetuses from mothers with preterm labor with intact membranes or preterm prelabor rupture of membranes, had higher concentrations of neuron-specific enolase (11804.6pg/ml (6213.4;21098.8), 8397.7 pg/ml (3682.1;17398.3) and 2393.7pg/ml (1717.1;3209.3), respectively (p<0.001)); protein S100B (2030.6 pg/ml (993;4883.5), 1070.3pg/ml (365.1-1463.2) and 74.8pg/ml (44.7;93.7), respectively (p<0.001)), and glial fibrillary acidic protein (1.01ng/ml (0.54;3.88), 0.965ng/ml (0.59;2.07) and 0.24mg/ml (0.20;0.28), respectively (p=0.002)). CONCLUSION: Fetuses with preterm labor with intact membranes or preterm prelabor rupture of membranes had prenatal signs of brain remodeling and injury at the time of clinical presentation. These changes were more pronounced in those with intra-amniotic inflammation.

Report of a Novel Homozygous Intragenic DCC Duplication and a Review of Literature of Developmental Split-Brain Syndrome aka Horizontal Gaze Palsy with Progressive Scoliosis-2 with Impaired Intellectual Development Syndrome.

Introduction: Horizontal gaze palsy with progressive scoliosis-2 (HGPPS2, MIM 617542) with impaired intellectual development aka developmental split-brain syndrome is an ultra-rare congenital disorder caused by pathogenic biallelic variants in the deleted in colorectal cancer (DCC) gene. Case Presentation: We report the clinical and genetic characterization of a Syrian patient with a HGPPS2 phenotype and review the previously published cases of HGPPS2. The genetic screening was performed using exome sequencing on Illumina platform. Genetic analysis revealed a novel DCC c.(?_1912)_(2359_?)dup, p.(Ser788Tyrfs*4) variant segregating recessively in the family. This type of variant has not been described previously in the HGPPS2 patients. To date, including the case reported here, three different homozygous pathogenic frameshift variants, one homozygous missense variant, and an intragenic duplication in the DCC gene have been reported in 8 patients with the HGPPS2 syndrome. Conclusion: The analysis of duplications and deletions in the DCC should be included in the routine genetic diagnostic evaluation of patients with suspected HGPPS2. This report expands the knowledge of phenotypic and genotypic spectrum of pathogenic variants causing HGPPS2.

Prenatal Identification of a Missense Mutation of the L1CAM Gene Associated With Hydrocephalus Using Next-Generation Sequencing.

We present the case of a 35-year-old pregnant woman who visited our department for a routine ultrasonography screening scan for fetus anatomy during the 22nd week of gestation. Our report revealed a male fetus with marked hydrocephalus and severe intrauterine growth retardation. After extensive counseling, the couple decided to proceed with an invasive diagnosis via amniocentesis. The cytogenetic analysis showed findings related to clinical history and ultrasound findings related to the presence of a nucleotide change in c.578T>C with an amino acid change in p.Leu198Pro of the L1CAM gene. The result was reported as a hemizygote missense L1CAM gene variant of unknown significance. After extensive parental counseling, the couple decided on pregnancy termination. We report the present case of L1CAM mutation in p.Leu198Pro to add to the limited knowledge regarding the clinical presentation of mutations of the L1CAM gene with emphasis on prenatal diagnosis.

A rare case of simultaneous occurrence of non-arteritic anterior ischemic optic neuropathy and corpus callosum ischemia.

PURPOSE: To report a case of non-arteritic anterior ischemic optic neuropathy (NAION) in an elderly patient with ischemia of the left splenium of the corpus callosum, providing details of the diagnostic work-up and subsequent follow-up. METHODS SECTION: Case report. RESULTS: A pseudophakic 80 years-old woman referred complaining sudden visual impairment in the left eye (LE) in concomitance with episode of hypertensive crisis. Fundus examination showed diffuse swelling of optic disc associated with flame peripapillary hemorrhages in LE and small crowded disc in right eye (RE). A superior altitudinal defect with arcuate defect including the blind spot were detected at the visual field in the LE. The patient was diagnosed with NAION. Five days later the patient complained a further vision loss and a pathological area within the left splenium of corpus callosum, consistent ischemia, was depicted at magnetic resonance imaging of brain. Corpus callosum infarction was completely asymptomatic and neurological evaluation was normal. At 45 days follow-up fundus examination showed white ischemic nerve while visual field was irreversibly constricted with tubular defect in LE. CONCLUSION: In case of NAION linked with corpus callosum ischemia multimodal imaging and systemic work-up play a pivotal role for an early diagnosis.