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The nuclear factor I (NFI) family of transcription factors play an important role in normal development of multiple organs. Three NFI family members are highly expressed in the brain, and deletions or sequence variants in two of these, NFIA and NFIX, have been associated with intellectual disability (ID) and brain malformations. NFIB, however, has not previously been implicated in human disease. Here, we present a cohort of 18 individuals with mild ID and behavioral issues who are haploinsufficient for NFIB. Ten individuals harbored overlapping microdeletions of the chromosomal 9p23-p22.2 region, ranging in size from 225 kb to 4.3 Mb. Five additional subjects had point sequence variations creating a premature termination codon, and three subjects harbored single-nucleotide variations resulting in an inactive protein as determined using an in vitro reporter assay. All individuals presented with additional variable neurodevelopmental phenotypes, including muscular hypotonia, motor and speech delay, attention deficit disorder, autism spectrum disorder, and behavioral abnormalities. While structural brain anomalies, including dysgenesis of corpus callosum, were variable, individuals most frequently presented with macrocephaly. To determine whether macrocephaly could be a functional consequence of NFIB disruption, we analyzed a cortex-specific Nfib conditional knockout mouse model, which is postnatally viable. Utilizing magnetic resonance imaging and histology, we demonstrate that Nfib conditional knockout mice have enlargement of the cerebral cortex but preservation of overall brain structure and interhemispheric connectivity. Based on our findings, we propose that haploinsufficiency of NFIB causes ID with macrocephaly.

Calcium/calmodulin-dependent protein kinase II (CAMK2) is one of the first proteins shown to be essential for normal learning and synaptic plasticity in mice, but its requirement for human brain development has not yet been established. Through a multi-center collaborative study based on a whole-exome sequencing approach, we identified 19 exceedingly rare de novo CAMK2A or CAMK2B variants in 24 unrelated individuals with intellectual disability. Variants were assessed for their effect on CAMK2 function and on neuronal migration. For both CAMK2A and CAMK2B, we identified mutations that decreased or increased CAMK2 auto-phosphorylation at Thr286/Thr287. We further found that all mutations affecting auto-phosphorylation also affected neuronal migration, highlighting the importance of tightly regulated CAMK2 auto-phosphorylation in neuronal function and neurodevelopment. Our data establish the importance of CAMK2A and CAMK2B and their auto-phosphorylation in human brain function and expand the phenotypic spectrum of the disorders caused by variants in key players of the glutamatergic signaling pathway.

Targeted DNA enrichment coupled with next generation sequencing has been increasingly used for interrogation of select sub-genomic regions at high depth of coverage in a cost effective manner. Specificity measured by on-target efficiency is a key performance metric for target enrichment. Non-specific capture leads to off-target reads, resulting in waste of sequencing throughput on irrelevant regions. Microdroplet-PCR allows simultaneous amplification of up to thousands of regions in the genome and is among the most commonly used strategies for target enrichment. Here we show that carryover of single-stranded template genomic DNA from microdroplet-PCR constitutes a major contributing factor for off-target reads in the resultant libraries. Moreover, treatment of microdroplet-PCR enrichment products with a nuclease specific to single-stranded DNA alleviates off-target load and improves enrichment specificity. We propose that nuclease treatment of enrichment products should be incorporated in the workflow of targeted sequencing using microdroplet-PCR for target capture. These findings may have a broad impact on other PCR based applications for which removal of template DNA is beneficial.

ClinVar provides open access to variant classifications shared from many clinical laboratories. Although most classifications are consistent across laboratories, classification differences exist. To facilitate resolution of classification differences on a large scale, clinical laboratories were encouraged to reassess outlier classifications of variants with medically significant differences (MSDs). Outliers were identified by first comparing ClinVar submissions from 41 clinical laboratories to detect variants with MSDs between the laboratories (650 variants). Next, MSDs were filtered for variants with ≥3 classifications (244 variants), of which 87.6% (213 variants) had a majority consensus in ClinVar, thus allowing for identification of outlier classifications in need of reassessment. Laboratories with outlier classifications were sent a custom report and encouraged to reassess variants. Results were returned for 204 (96%) variants, of which 62.3% (127) were resolved. Of those 127, 64.6% (82) were resolved due to reassessment prompted by this study and 35.4% (45) resolved by a previously completed reassessment. This study demonstrates a scalable approach to classification resolution and capitalizes on the value of data sharing within ClinVar. These activities will help the community move toward more consistent variant classifications, which will improve the care of patients with, or at risk for, genetic disorders. To facilitate resolution of sequence variant classification differences in ClinVar, clinical laboratories were sent a custom report of outlier interpretations and encouraged to reassess variants. Among 650 variants with medically significant differences between laboratories, 31% (204 variants) had an outlier classification, of which 62.3% (127 variants) were reclassified and resolved upon outlier laboratory reassessment alone. This study demonstrates a scalable approach to tackle a portion of classification resolution and capitalizes on the value of data sharing within ClinVar. [ABSTRACT FROM AUTHOR]

In recent years, anti-CD20 antibodies have been increasingly used to treat lymphoproliferative and immune disorders. Chronic viral infections are infrequently reported in patients receiving these therapies. Enteroviral infection can cause life-threatening meningoencephalitis and other systemic chronic syndromes in immune deficient patients. We describe the clinical courses and outcomes of 6 patients from 2 tertiary care institutions who developed chronic enteroviral infection with neurological manifestations, after combined chemoimmunotherapy with rituximab for B-cell lymphoma. We review the literature that includes 10 sporadic reported cases of chronic enteroviral meningoencephalitis attributed to rituximab therapy. It is a rare disease, and its diagnosis is often elusive. We propose that low immunoglobulin G levels are the main risk factor for developing chronic enteroviral infection and emphasize the need for a high index of suspicion, early diagnosis, and intervention in this iatrogenic and potentially fatal complication. [ABSTRACT FROM AUTHOR]

The objective of this study was to examine whether aortic stiffness, as assessed by pulse wave analysis, could reliably discriminate between normal and hypertensive pregnancies. One hundred pregnant women were studied: five with severe pre-eclampsia, 27 with gestational hypertension, 14 with chronic hypertension and 54 with normal pregnancy. Central hemodynamic parameters were obtained by an applanation tonometry and included central aortic systolic blood pressure (CSBP), central aortic diastolic blood pressure (CDBP), augmentation pressure (AP), augmentation index (AIx), AIx corrected to a heart rate of 75 (AIx@75) and time to reflection (Tr). All measures of aortic stiffness, including AP, AIx and AIx@75 were significantly higher in women with gestational hypertension and pre-eclampsia compared with normal pregnancies and women with chronic hypertension ( p < 0.05 for all comparisons). There were no significant differences between normal pregnancies and women with chronic hypertension ( p > 0.05 for all comparisons). Tr was significantly shorter in women with pre-eclampsia and gestational hypertension compared with normal pregnancies ( p < 0.05). Aortic stiffness, as assessed by pulse wave analysis, is significantly increased in women with pre-eclampsia and gestational hypertension but not in treated women with chronic hypertension. Pulse wave analysis has a potential as a screening tool in women at high risk for pre-eclampsia. The final role of this method should be determined in prospective studies. [ABSTRACT FROM AUTHOR]

The long-term effects of octreotide, the synthetic analog of the hormone somatostatin, on acute experimental pancreatitis were studied. Acute pancreatitis was induced in rats by intraparenchymal injections of 0.5 ml 5% or 10% sodium taurocholate. Octreotide (10 mg/kg/day, subcutaneously), or saline injections as controls, were started four hours later, and their effects were assessed 30, 60, and 90 days after the induction of pancreatitis. Neither intrapancreatic saline injections nor octreotide administration without the induction of pancreatitis caused any biochemical or histological abnormalities. Taurocholate-induced pancreatitis was followed by remarkable hyperglycemia, which was ameliorated by octreotide. Thirty days after induction of pancreatitis, glucose levels were 269+/-21 mg/100 ml and 153+/-17 mg/100 ml in the control and octreotide treated animals, respectively (P < 0.02). Octreotide administration was associated with increased pH values after 60 and 90 days (P < 0.05 for the 90 days group). The levels of hematocrit, calcium, and amylase were already within the normal ranges after 30 days and were unaffected by octreotide. There were no signs of chronic exocrine insufficiency and all the surviving rats gained weight during the follow-up. However, the relative weights of the pancreases of the octreotide-treated animals were higher than those of the controls 30 days after IOP. Histopathological evaluation demonstrated regeneration of the pancreatic tissue, and increased number and hypertrophy of the islets of Langherhans. There were no significant differences whether the octreotide treatment was given for only 48 or 96 hr. Survival was significantly improved by octreotide; only one octreotide-treated rat (2.5%) with 10% taurocholate-induced pancreatitis died, while six (15%) of the control animals succumbed (P < 0.05). These studies provided data on the sequelae of acute pancreatitis and showed that octreotide may have long-term beneficial effects in this disease. [ABSTRACT FROM AUTHOR]