@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} }