@article {71, title = {Genome-Wide Association and Exome Sequencing Study of Language Disorder in an Isolated Population.}, journal = {Pediatrics}, volume = {137}, year = {2016}, month = {2016 04}, abstract = {

BACKGROUND AND OBJECTIVE: Developmental language disorder (DLD) is a highly prevalent neurodevelopmental disorder associated with negative outcomes in different domains; the etiology of DLD is unknown. To investigate the genetic underpinnings of DLD, we performed genome-wide association and whole exome sequencing studies in a geographically isolated population with a substantially elevated prevalence of the disorder (ie, the AZ sample).

METHODS: DNA samples were collected from 359 individuals for the genome-wide association study and from 12 severely affected individuals for whole exome sequencing. Multifaceted phenotypes, representing major domains of expressive language functioning, were derived from collected speech samples.

RESULTS: Gene-based analyses revealed a significant association between SETBP1 and complexity of linguistic output (P = 5.47 {\texttimes} 10(-7)). The analysis of exome variants revealed coding sequence variants in 14 genes, most of which play a role in neural development. Targeted enrichment analysis implicated myocyte enhancer factor-2 (MEF2)-regulated genes in DLD in the AZ population. The main findings were successfully replicated in an independent cohort of children at risk for related disorders (n = 372).

CONCLUSIONS: MEF2-regulated pathways were identified as potential candidate pathways in the etiology of DLD. Several genes (including the candidate SETBP1 and other MEF2-related genes) seem to jointly influence certain, but not all, facets of the DLD phenotype. Even when genetic and environmental diversity is reduced, DLD is best conceptualized as etiologically complex. Future research should establish whether the signals detected in the AZ population can be replicated in other samples and languages and provide further characterization of the identified pathway.

}, keywords = {Adolescent, Adult, Aged, Aged, 80 and over, Child, Child, Preschool, Exome, Genome-Wide Association Study, Humans, Language Disorders, Middle Aged, Polymorphism, Single Nucleotide, Russia, Sequence Analysis, DNA, Young Adult}, issn = {1098-4275}, doi = {10.1542/peds.2015-2469}, author = {Kornilov, Sergey A and Rakhlin, Natalia and Koposov, Roman and Lee, Maria and Yrigollen, Carolyn and {\c C}a{\u g}layan, Ahmet Okay and Magnuson, James S and Mane, Shrikant and Chang, Joseph T and Grigorenko, Elena L} } @article {208, title = {Brain malformations associated with Knobloch syndrome--review of literature, expanding clinical spectrum, and identification of novel mutations.}, journal = {Pediatr Neurol}, volume = {51}, year = {2014}, month = {2014 Dec}, pages = {806-813.e8}, abstract = {

BACKGROUND: Knobloch syndrome is a rare, autosomal recessive, developmental disorder characterized by stereotyped ocular abnormalities with or without occipital skull deformities (encephalocele, bone defects, and cutis aplasia). Although there is clear heterogeneity in clinical presentation, central nervous system malformations, aside from the characteristic encephalocele, have not typically been considered a component of the disease phenotype.

METHODS: Four patients originally presented for genetic evaluation of symptomatic structural brain malformations. Whole-genome genotyping, whole-exome sequencing, and confirmatory Sanger sequencing were performed. Using immunohistochemical analysis, we investigated the protein expression pattern of COL18A1 in the mid-fetal and adult human cerebral cortex and then analyzed the spatial and temporal changes in the expression pattern of COL18A1 during human cortical development using the Human Brain Transcriptome database.

RESULTS: We identified two novel homozygous deleterious frame-shift mutations in the COL18A1 gene. On further investigation of these patients and their families, we found that many exhibited certain characteristics of Knobloch syndrome, including pronounced ocular defects. Our data strongly support an important role for COL18A1 in brain development, and this report contributes to an enhanced characterization of the brain malformations that can result from deficiencies of collagen XVIII.

CONCLUSIONS: This case series highlights the diagnostic power and clinical utility of whole-exome sequencing technology-allowing clinicians and physician scientists to better understand the pathophysiology and presentations of rare diseases. We suggest that patients who are clinically diagnosed with Knobloch syndrome and/or found to have COL18A1 mutations via genetic screening should be investigated for potential structural brain abnormalities even in the absence of an encephalocele.

}, keywords = {Adolescent, Adult, Cerebral Cortex, Collagen Type XVIII, Consanguinity, Encephalocele, Exome, Female, Fetus, Humans, Male, Mutation, Retinal Degeneration, Retinal Detachment, Young Adult}, issn = {1873-5150}, doi = {10.1016/j.pediatrneurol.2014.08.025}, author = {{\c C}a{\u g}layan, Ahmet Okay and Baranoski, Jacob F and Aktar, Fesih and Han, Wengi and Tuysuz, Beyhan and Guzel, Aslan and Guclu, Bulent and Kaymak{\c c}alan, Hande and Aktekin, Berrin and Akg{\"u}m{\"u}{\c s}, G{\"o}zde Tu{\u g}ce and Murray, Phillip B and Erson-Omay, Emine Z and Caglar, Caner and Bakircioglu, Mehmet and Sakalar, Yildirim Bayezit and Guzel, Ebru and Demir, Nihat and Tuncer, Oguz and Senturk, Senem and Ekici, Bar{\i}{\c s} and Minja, Frank J and {\v S}estan, Nenad and Yasuno, Katsuhito and Bilguvar, Kaya and Caksen, Huseyin and G{\"u}nel, Murat} }