Mutations in the fibroblast growth factor receptor 1, 2 and 3 (FGFR1, -2 and -3) and TWIST genes have been identified in several syndromic forms of craniosynostosis. There remains, however, a significant number of patients with non-syndromic craniosynostosis in whom no genetic cause can be identified. We describe a novel heterozygous mutation of FGFR2 (943G ® T, encoding the amino acid substitution Ala315Ser) in a girl with non-syndromic unicoronal craniosynostosis. The mutation is also present in her mother and her maternal grandfather who have mild facial asymmetry but do not have craniosynostosis. None of these individuals has the Crouzonoid appearance typically associated with FGFR2 mutations. However, the obstetric history revealed that the proband was in persistent breech presentation in utero and was delivered by Caesarean section, at which time compression of the skull was apparent. We propose that this particular FGFR2 mutation only confers a predisposition to craniosynostosis and that an additional environmental insult (in this case foetal head constraint associated with breech position) is necessary for craniosynostosis to occur. To our knowledge, this is the first report of an interaction between a weakly pathogenic mutation and intrauterine constraint, leading to craniosynostosis.

The baculovirus expression system is one of the most popular methods used for the production of recombinant proteins but has several complex steps which have proved inherently difficult to adapt to a multi-parallel process. We have developed a bacmid vector that does not require any form of selection pressure to separate recombinant virus from non-recombinant parental virus. The method relies on homologous recombination in insect cells between a transfer vector containing a gene to be expressed and a replication-deficient bacmid. The target gene replaces a bacterial replicon at the polyhedrin loci, simultaneously restoring a virus gene essential for replication. Therefore, only recombinant virus can replicate facilitating the rapid production of multiple recombinant viruses on automated platforms in a one-step procedure. Using this vector allowed us to automate the generation of multiple recombinant viruses with a robotic liquid handler and then rapidly screen infected insect cell supernatant for the presence of secreted proteins.

Motor learning requires protein synthesis within the primary motor cortex (M1). Here, we show that the immediate early gene Arc/Arg3.1 is specifically induced in M1 by learning a motor skill. Arc mRNA was quantified using a fluorescent in situ hybridization assay in adult Long-Evans rats learning a skilled reaching task (SRT), in rats performing reaching-like forelimb movement without learning (ACT) and in rats that were trained in the operant but not the motor elements of the task (controls). Apart from M1, Arc expression was assessed within the rostral motor area (RMA), primary somatosensory cortex (S1), striatum (ST) and cerebellum. In SRT animals, Arc mRNA levels in M1 contralateral to the trained limb were 31% higher than ipsilateral (p<0.001), 31% higher than in the contralateral M1 of ACT animals (p<0.001) and 48% higher than in controls (p<0.001). Arc mRNA expression in SRT was positively correlated with learning success between two sessions (r=0.52; p=0.026). For RMA, S1, ST or cerebellum no significant differences in Arc mRNA expression were found between hemispheres or across behaviors. As Arc expression has been related to different forms of cellular plasticity, these findings suggest a link between M1 Arc expression and motor skill learning in rats.

A 7-year-old female with developmental delay (DD), autism spectrum disorder (ASD), intellectual disability (ID), attention deficit hyperactivity disorder (ADHD), and seizures was referred to our laboratory for oligomicroarray analysis. The analysis revealed a 540 kb microdeletion in the chromosome 8q24.3 region (143,610,058-144,150,241) encompassing multiple genes. Two siblings of the proband were also analyzed. The proband's older sister with DD, seizures, and ASD has a 438 kb intragenic microdeletion of the GPHN gene in the chromosome 14q23.3 region (67,105,512-67,543,291) containing multiple exons, while the proband's older brother with DD, ASD, ID, and ADHD has both the 8q24.3 and the 14q23.3 deletions. All three siblings have a normal karyotype at the 650 G-band level of resolution. Parental FISH analysis indicates that the mother is a carrier for the 8q24.3 deletion and the father is a carrier for the 14q23.3 deletion. The 8q24.3 deletion seen in our patients has not been reported in the literature, while the small deletions of the 14q23.3 region involving multiple exons of the GPHN gene have been reported in a handful of patients in a recent study. The size of the 8q24.3 deletion and its genomic content, as well as the maternal family history, strongly suggest the association between the deletion and the neurodevelopmental disorders. Our study also provides more evidence in support of the association between GPHN deletion and neurodevelopmental disorders.