👤 Kaitlyn Dal Bon

There is a subgroup of people infected with the SARS-CoV-2 virus who manifest lingering sequelae (LongC), with neurological symptoms (nLongC). We recruited 86 COVID-19 volunteers, 35 of whom were fully recovered (Cov) and 51 who had neurological symptoms (nLongC) 4-53 months after infection and compared them to 51 healthy pre-pandemic controls (HC). Thirty-five percent of nLongC individuals carried the apolipoprotein E4 (APOE4) gene, compared to 11% of Cov. Four plasma proteins, interleukin 1 beta (IL-1β), interleukin 8 (IL-8), glial fibrillary acidic protein (GFAP), and hemopexin, continued to be elevated in both Cov and nLongC compared to HC. Soluble CD14 was elevated in nLongC but not Cov. As a group, IL-1β decreased over time in Cov but not nLongC. Two of the elevated proteins, IL-8 and GFAP, correlated with age, with both Cov and nLongC showing higher levels than HC. Using a combination of four plasma proteins, along with age, body mass index, and APOE4 presence, we were able to achieve an area under the curve (AUC) of 0.81. These results suggest that SARS-CoV-2 infection causes a low-grade inflammatory process that, even months or years after infection, does not return to pre-COVID-19 levels, which may contribute to neurologic sequelae and accelerated aging. Show less

Corpus callosum malformations are associated with a broad range of neurodevelopmental diseases. We report that de novo mutations in MAST1 cause mega-corpus-callosum syndrome with cerebellar hypoplasia and cortical malformations (MCC-CH-CM) in the absence of megalencephaly. We show that MAST1 is a microtubule-associated protein that is predominantly expressed in post-mitotic neurons and is present in both dendritic and axonal compartments. We further show that Mast1 null animals are phenotypically normal, whereas the deletion of a single amino acid (L278del) recapitulates the distinct neurological phenotype observed in patients. In animals harboring Mast1 microdeletions, we find that the PI3K/AKT3/mTOR pathway is unperturbed, whereas Mast2 and Mast3 levels are diminished, indicative of a dominant-negative mode of action. Finally, we report that de novo MAST1 substitutions are present in patients with autism and microcephaly, raising the prospect that mutations in this gene give rise to a spectrum of neurodevelopmental diseases. Show less

Copy-number variations (CNVs) are a common cause of intellectual disability and/or multiple congenital anomalies (ID/MCA). However, the clinical interpretation of CNVs remains challenging, especially for inherited CNVs. Well-phenotyped patients (5,531) with ID/MCA were screened for rare CNVs using a 250K single-nucleotide polymorphism array platform in order to improve the understanding of the contribution of CNVs to a patients phenotype. We detected 1,663 rare CNVs in 1,388 patients (25.1%; range 0-5 per patient) of which 437 occurred de novo and 638 were inherited. The detected CNVs were analyzed for various characteristics, gene content, and genotype-phenotype correlations. Patients with severe phenotypes, including organ malformations, had more de novo CNVs (P < 0.001), whereas patient groups with milder phenotypes, such as facial dysmorphisms, were enriched for both de novo and inherited CNVs (P < 0.001), indicating that not only de novo but also inherited CNVs can be associated with a clinically relevant phenotype. Moreover, patients with multiple CNVs presented with a more severe phenotype than patients with a single CNV (P < 0.001), pointing to a combinatorial effect of the additional CNVs. In addition, we identified 20 de novo single-gene CNVs that directly indicate novel genes for ID/MCA, including ZFHX4, ANKH, DLG2, MPP7, CEP89, TRIO, ASTN2, and PIK3C3. Show less