@article {584, title = {Megabase Length Hypermutation Accompanies Human Structural Variation at 17p11.2.}, journal = {Cell}, volume = {176}, year = {2019}, month = {2019 03 07}, pages = {1310-1324.e10}, abstract = {

DNA rearrangements resulting in human genome structural variants (SVs) are caused by diverse mutational mechanisms. We used long- and short-read sequencing technologies to investigate end products of de novo chromosome 17p11.2 rearrangements and query the molecular mechanisms underlying both recurrent and non-recurrent events. Evidence for an increased rate of clustered single-nucleotide variant (SNV) mutation in cis with non-recurrent rearrangements was found. Indel and SNV formation are associated with both copy-number gains and losses of 17p11.2, occur up to \~{}1 Mb away from the breakpoint junctions, and favor C > G transversion substitutions; results suggest that single-stranded DNA is formed during the genesis of the SV and provide compelling support for a microhomology-mediated break-induced replication (MMBIR) mechanism for SV formation. Our data show an additional mutational burden of MMBIR consisting of hypermutation confined to the locus and manifesting as SNVs and indels predominantly within genes.

}, issn = {1097-4172}, doi = {10.1016/j.cell.2019.01.045}, author = {Beck, Christine R and Carvalho, Claudia M B and Akdemir, Zeynep C and Sedlazeck, Fritz J and Song, Xiaofei and Meng, Qingchang and Hu, Jianhong and Doddapaneni, Harsha and Chong, Zechen and Chen, Edward S and Thornton, Philip C and Liu, Pengfei and Yuan, Bo and Withers, Marjorie and Jhangiani, Shalini N and Kalra, Divya and Walker, Kimberly and English, Adam C and Han, Yi and Chen, Ken and Muzny, Donna M and Ira, Grzegorz and Shaw, Chad A and Gibbs, Richard A and Hastings, P J and Lupski, James R} } @article {91, title = {Hutterite-type cataract maps to chromosome 6p21.32-p21.31, cosegregates with a homozygous mutation in LEMD2, and is associated with sudden cardiac death.}, journal = {Mol Genet Genomic Med}, volume = {4}, year = {2016}, month = {2016 Jan}, pages = {77-94}, abstract = {

BACKGROUND: Juvenile-onset cataracts are known among the Hutterites of North America. Despite being identified over 30~years ago, this autosomal recessive condition has not been mapped, and the disease gene is unknown.

METHODS: We performed whole exome sequencing of three Hutterite-type cataract trios and follow-up genotyping and mapping in four extended kindreds.

RESULTS: Trio exomes enabled genome-wide autozygosity mapping, which localized the disease gene to a 9.5-Mb region on chromosome 6p. This region contained two candidate variants, LEMD2 c.T38G and MUC21 c.665delC. Extended pedigrees recruited for variant genotyping revealed multiple additional relatives with juvenile-onset cataract, as well as six deceased relatives with both cataracts and sudden cardiac death. The candidate variants were genotyped in 84 family members, including 17 with cataracts; only the variant in LEMD2 cosegregated with cataracts (LOD~=~9.62). SNP-based fine mapping within the 9.5~Mb linked region supported this finding by refining the cataract locus to a 0.5- to 2.9-Mb subregion (6p21.32-p21.31) containing LEMD2 but not MUC21. LEMD2 is expressed in mouse and human lenses and encodes a LEM domain-containing protein; the c.T38G missense mutation is predicted to mutate a highly conserved residue within this domain (p.Leu13Arg).

CONCLUSION: We performed a genetic and genomic study of Hutterite-type cataract and found evidence for an association of this phenotype with sudden cardiac death. Using combined genetic and genomic approaches, we mapped cataracts to a small portion of chromosome 6 and propose that they result from a homozygous missense mutation in LEMD2.

}, issn = {2324-9269}, doi = {10.1002/mgg3.181}, author = {Boone, Philip M and Yuan, Bo and Gu, Shen and Ma, Zhiwei and Gambin, Tomasz and Gonzaga-Jauregui, Claudia and Jain, Mahim and Murdock, Todd J and White, Janson J and Jhangiani, Shalini N and Walker, Kimberly and Wang, Qiaoyan and Muzny, Donna M and Gibbs, Richard A and Hejtmancik, J Fielding and Lupski, James R and Posey, Jennifer E and Lewis, Richard A} }