@article {115, title = {Whole-Exome Sequencing in Familial Parkinson Disease.}, journal = {JAMA Neurol}, volume = {73}, year = {2016}, month = {2016 Jan}, pages = {68-75}, abstract = {

IMPORTANCE: Parkinson disease (PD) is a progressive neurodegenerative disease for which susceptibility is linked to genetic and environmental risk factors.

OBJECTIVE: To identify genetic variants contributing to disease risk in familial PD.

DESIGN, SETTING, AND PARTICIPANTS: A 2-stage study design that included a discovery cohort of families with PD and a replication cohort of familial probands was used. In the discovery cohort, rare exonic variants that segregated in multiple affected individuals in a family and were predicted to be conserved or damaging were retained. Genes with retained variants were prioritized if expressed in the brain and located within PD-relevant pathways. Genes in which prioritized variants were observed in at least 4 families were selected as candidate genes for replication in the replication cohort. The setting was among individuals with familial PD enrolled from academic movement disorder specialty clinics across the United States. All participants had a family history of PD.

MAIN OUTCOMES AND MEASURES: Identification of genes containing rare, likely deleterious, genetic variants in individuals with familial PD using a 2-stage exome sequencing study design.

RESULTS: The 93 individuals from 32 families in the discovery cohort (49.5\% [46 of 93] female) had a mean (SD) age at onset of 61.8 (10.0) years. The 49 individuals with familial PD in the replication cohort (32.6\% [16 of 49] female) had a mean (SD) age at onset of 50.1 (15.7) years. Discovery cohort recruitment dates were 1999 to 2009, and replication cohort recruitment dates were 2003 to 2014. Data analysis dates were 2011 to 2015. Three genes containing a total of 13 rare and potentially damaging variants were prioritized in the discovery cohort. Two of these genes (TNK2 and TNR) also had rare variants that were predicted to be damaging in the replication cohort. All 9 variants identified in the 2 replicated genes in 12 families across the discovery and replication cohorts were confirmed via Sanger sequencing.

CONCLUSIONS AND RELEVANCE: TNK2 and TNR harbored rare, likely deleterious, variants in individuals having familial PD, with similar findings in an independent cohort. To our knowledge, these genes have not been previously associated with PD, although they have been linked to critical neuronal functions. Further studies are required to confirm a potential role for these genes in the pathogenesis of PD.

}, keywords = {Adult, Aged, Cohort Studies, Exome, Female, Genetic Predisposition to Disease, Genetic Variation, Humans, Male, Middle Aged, Parkinsonian Disorders, Protein-Tyrosine Kinases, Sequence Analysis, DNA, Tenascin}, issn = {2168-6157}, doi = {10.1001/jamaneurol.2015.3266}, author = {Farlow, Janice L and Robak, Laurie A and Hetrick, Kurt and Bowling, Kevin and Boerwinkle, Eric and Coban-Akdemir, Zeynep H and Gambin, Tomasz and Gibbs, Richard A and Gu, Shen and Jain, Preti and Jankovic, Joseph and Jhangiani, Shalini and Kaw, Kaveeta and Lai, Dongbing and Lin, Hai and Ling, Hua and Liu, Yunlong and Lupski, James R and Muzny, Donna and Porter, Paula and Pugh, Elizabeth and White, Janson and Doheny, Kimberly and Myers, Richard M and Shulman, Joshua M and Foroud, Tatiana} } @article {199, title = {Assessment of incidental findings in 232 whole-exome sequences from the Baylor-Hopkins Center for Mendelian Genomics.}, journal = {Genet Med}, volume = {17}, year = {2015}, month = {2015 Oct}, pages = {782-8}, abstract = {

PURPOSE: In March 2013 the American College of Medical Genetics and Genomics published a list of 56 genes with the recommendation that pathogenic and likely pathogenic variants detected incidentally by clinical sequencing be reported to patients. As an initial step in determining the practical consequences of this recommendation in the research setting, we searched for variants in these genes in 232 whole-exome sequences from the Baylor-Hopkins Center for Mendelian Genomics.

METHODS: We identified rare, nonsynonymous, and splicing single-nucleotide variants and insertions/deletions and assessed variant classification using the Human Gene Mutation, Emory, and ClinVar databases. We analyzed the burden of mutation in each of the 56 genes and determined which variants should be reported to patients.

RESULTS: Our filtering resulted in 249 distinct variants, with a mean of 1.69 variants per individual. Half of these were novel missense mutations not classified by any of the three reference databases. Of 101 variants listed in the Human Gene Mutation Database, 48 were also in ClinVar and 3 were also in Emory; half of these shared variants were classified discordantly between databases. Some genes consistently had greater variation than others. In total, 0.86\% of individuals had a reportable incidental variant.

CONCLUSION: These observations demonstrate some current challenges of assessing phenotypic consequences of incidental variants for counseling patients.

}, keywords = {Databases, Nucleic Acid, Exome, Female, Genetic Diseases, Inborn, Genomics, High-Throughput Nucleotide Sequencing, Humans, Incidental Findings, Male, Mutation, Polymorphism, Single Nucleotide}, issn = {1530-0366}, doi = {10.1038/gim.2014.196}, author = {Jurgens, Julie and Ling, Hua and Hetrick, Kurt and Pugh, Elizabeth and Schiettecatte, Fran{\c c}ois and Doheny, Kimberly and Hamosh, Ada and Avramopoulos, Dimitri and Valle, David and Sobreira, Nara} }