@article {789, title = {Diagnostic yield and clinical impact of exome sequencing in early-onset scoliosis (EOS).}, journal = {J Med Genet}, volume = {58}, year = {2021}, month = {2021 Jan}, pages = {41-47}, abstract = {

BACKGROUND: Early-onset scoliosis (EOS), defined by an onset age of scoliosis less than 10 years, conveys significant health risk to affected children. Identification of the molecular aetiology underlying patients with EOS could provide valuable information for both clinical management and prenatal screening.

METHODS: In this study, we consecutively recruited a cohort of 447 Chinese patients with operative EOS. We performed exome sequencing (ES) screening on these individuals and their available family members (totaling 670 subjects). Another cohort of 13 patients with idiopathic early-onset scoliosis (IEOS) from the USA who underwent ES was also recruited.

RESULTS: After ES data processing and variant interpretation, we detected molecular diagnostic variants in 92 out of 447 (20.6\%) Chinese patients with EOS, including 8 patients with molecular confirmation of their clinical diagnosis and 84 patients with molecular diagnoses of previously unrecognised diseases underlying scoliosis. One out of 13 patients with IEOS from the US cohort was molecularly diagnosed. The age at presentation, the number of organ systems involved and the Cobb angle were the three top features predictive of a molecular diagnosis.

CONCLUSION: ES enabled the molecular diagnosis/classification of patients with EOS. Specific clinical features/feature pairs are able to indicate the likelihood of gaining a molecular diagnosis through ES.

}, issn = {1468-6244}, doi = {10.1136/jmedgenet-2019-106823}, author = {Zhao, Sen and Zhang, Yuanqiang and Chen, Weisheng and Li, Weiyu and Wang, Shengru and Wang, Lianlei and Zhao, Yanxue and Lin, Mao and Ye, Yongyu and Lin, Jiachen and Zheng, Yu and Liu, Jiaqi and Zhao, Hengqiang and Yan, Zihui and Yang, Yongxin and Huang, Yingzhao and Lin, Guanfeng and Chen, Zefu and Zhang, Zhen and Liu, Sen and Jin, Lichao and Wang, Zhaoyang and Chen, Jingdan and Niu, Yuchen and Li, Xiaoxin and Wu, Yong and Wang, Yipeng and Du, Renqian and Gao, Na and Zhao, Hong and Yang, Ying and Liu, Ying and Tian, Ye and Li, Wenli and Zhao, Yu and Liu, Jia and Yu, Bin and Zhang, Na and Yu, Keyi and Yang, Xu and Li, Shugang and Xu, Yuan and Hu, Jianhua and Liu, Zhe and Shen, Jianxiong and Zhang, Shuyang and Su, Jianzhong and Khanshour, Anas M and Kidane, Yared H and Ramo, Brandon and Rios, Jonathan J and Liu, Pengfei and Sutton, V Reid and Posey, Jennifer E and Wu, Zhihong and Qiu, Guixing and Wise, Carol A and Zhang, Feng and Lupski, James R and Zhang, Jianguo and Wu, Nan} } @article {983, title = {Perturbations of genes essential for M{\"u}llerian duct and W{\"o}lffian duct development in Mayer-Rokitansky-K{\"u}ster-Hauser syndrome.}, journal = {Am J Hum Genet}, volume = {108}, year = {2021}, month = {2021 02 04}, pages = {337-345}, abstract = {

Mayer-Rokitansky-K{\"u}ster-Hauser syndrome (MRKHS) is associated with congenital absence of the uterus, cervix, and the upper part of the vagina; it is a sex-limited trait. Disrupted development of the M{\"u}llerian ducts (MD)/W{\"o}lffian ducts (WD) through multifactorial mechanisms has been proposed to underlie MRKHS. In this study, exome sequencing (ES) was performed on a Chinese discovery cohort (442 affected subjects and 941 female control subjects) and a replication MRKHS cohort (150 affected subjects of mixed ethnicity from North America, South America, and Europe). Phenotypic follow-up of the female reproductive system was performed on an additional cohort of PAX8-associated congenital hypothyroidism (CH) (n = 5, Chinese). By analyzing 19 candidate genes essential for MD/WD development, we identified 12 likely gene-disrupting (LGD) variants in 7 genes: PAX8 (n = 4), BMP4 (n = 2), BMP7 (n = 2), TBX6 (n = 1), HOXA10 (n = 1), EMX2 (n = 1), and WNT9B (n = 1), while LGD variants in these genes were not detected in control samples (p = 1.27E-06). Interestingly, a sex-limited penetrance with paternal inheritance was observed in multiple families. One additional PAX8 LGD variant from the replication cohort and two missense variants from both cohorts were revealed to cause loss-of-function of the protein. From the PAX8-associated CH cohort, we identified one individual presenting a syndromic condition characterized by CH and MRKHS (CH-MRKHS). Our study demonstrates the comprehensive utilization of knowledge from developmental biology toward elucidating genetic perturbations, i.e., rare pathogenic alleles involving the same loci, contributing to human birth defects.

}, keywords = {46, XX Disorders of Sex Development, Adult, Bone Morphogenetic Protein 4, Bone Morphogenetic Protein 7, Codon, Nonsense, Congenital Abnormalities, Female, Genetic Association Studies, Genetic Pleiotropy, Homeobox A10 Proteins, Homeodomain Proteins, Humans, Mullerian Ducts, Mutation, Paternal Inheritance, PAX8 Transcription Factor, Penetrance, T-Box Domain Proteins, Transcription Factors, Wnt Proteins, Wolffian Ducts}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2020.12.014}, author = {Chen, Na and Zhao, Sen and Jolly, Angad and Wang, Lianlei and Pan, Hongxin and Yuan, Jian and Chen, Shaoke and Koch, Andr{\'e} and Ma, Congcong and Tian, Weijie and Jia, Ziqi and Kang, Jia and Zhao, Lina and Qin, Chenglu and Fan, Xin and Rall, Katharina and Coban-Akdemir, Zeynep and Chen, Zefu and Jhangiani, Shalini and Liang, Ze and Niu, Yuchen and Li, Xiaoxin and Yan, Zihui and Wu, Yong and Dong, Shuangshuang and Song, Chengcheng and Qiu, Guixing and Zhang, Shuyang and Liu, Pengfei and Posey, Jennifer E and Zhang, Feng and Luo, Guangnan and Wu, Zhihong and Su, Jianzhong and Zhang, Jianguo and Chen, Eugenia Y and Rouskas, Konstantinos and Glentis, Stavros and Bacopoulou, Flora and Deligeoroglou, Efthymios and Chrousos, George and Lyonnet, Stanislas and Polak, Michel and Rosenberg, Carla and Dingeldein, Irene and Bonilla, Ximena and Borel, Christelle and Gibbs, Richard A and Dietrich, Jennifer E and Dimas, Antigone S and Antonarakis, Stylianos E and Brucker, Sara Y and Lupski, James R and Wu, Nan and Zhu, Lan} } @article {708, title = {Genetic and molecular mechanism for distinct clinical phenotypes conveyed by allelic truncating mutations implicated in FBN1.}, journal = {Mol Genet Genomic Med}, volume = {8}, year = {2020}, month = {2020 01}, pages = {e1023}, abstract = {

BACKGROUND: The molecular and genetic mechanisms by which different single nucleotide variant alleles in specific genes, or at the same genetic locus, cause distinct disease phenotypes often remain unclear. Allelic truncating mutations of FBN1 could cause either classical Marfan syndrome (MFS) or a more complicated phenotype associated with Marfanoid-progeroid-lipodystrophy syndrome (MPLS).

METHODS: We investigated a small cohort, encompassing two classical MFS and one MPLS subjects~from China, whose clinical presentation included scoliosis potentially requiring surgical intervention. Targeted next generation sequencing was performed on all the participants. We analyzed the molecular diagnosis, clinical features, and the potential molecular mechanism involved in the MPLS subject in our cohort.

RESULTS: We report a novel de novo FBN1 mutation for the first Chinese subject~with MPLS, a more complicated fibrillinopathy, and two subjects~with more classical MFS. We further predict that the MPLS truncating mutation, and others previously reported, is prone to escape the nonsense-mediated decay (NMD), while MFS mutations are predicted to be subjected to NMD. Also, the MPLS mutation occurs within the glucogenic hormone asprosin domain of FBN1. In vitro experiments showed that the single MPLS mutation p.Glu2759Cysfs*9 appears to perturb proper FBN1 protein aggregation as compared with the~classical MFS mutation p.Tyr2596Thrfs*86. Both mutations appear to upregulate SMAD2 phosphorylation in vitro.

CONCLUSION: We provide direct evidence that a dominant-negative interaction of FBN1 potentially explains the complex MPLS phenotypes through genetic and functional analysis. Our study expands the mutation spectrum of FBN1 and highlights the potential molecular mechanism for MPLS.

}, keywords = {Adolescent, Adult, Child, Female, Fibrillin-1, HEK293 Cells, Humans, Lipodystrophy, Marfan Syndrome, Mutation, Phenotype, Progeria, Protein Domains, Smad2 Protein}, issn = {2324-9269}, doi = {10.1002/mgg3.1023}, author = {Lin, Mao and Liu, Zhenlei and Liu, Gang and Zhao, Sen and Li, Chao and Chen, Weisheng and Coban Akdemir, Zeynep and Lin, Jiachen and Song, Xiaofei and Wang, Shengru and Xu, Qiming and Zhao, Yanxue and Wang, Lianlei and Zhang, Yuanqiang and Yan, Zihui and Liu, Sen and Liu, Jiaqi and Chen, Yixin and Zuo, Yuzhi and Yang, Xu and Sun, Tianshu and Yang, Xin-Zhuang and Niu, Yuchen and Li, Xiaoxin and You, Wesley and Qiu, Bintao and Ding, Chen and Liu, Pengfei and Zhang, Shuyang and Carvalho, Claudia M B and Posey, Jennifer E and Qiu, Guixing and Lupski, James R and Wu, Zhihong and Zhang, Jianguo and Wu, Nan} } @article {793, title = {Increased gene dosages induce congenital cervical vertebral malformations in humans and mice.}, journal = {J Med Genet}, volume = {57}, year = {2020}, month = {2020 06}, pages = {371-379}, abstract = {

BACKGROUND: Congenital vertebral malformations (CVMs) manifest with abnormal vertebral morphology. Genetic factors have been implicated in CVM pathogenesis, but the underlying pathogenic mechanisms remain unclear in most subjects. We previously reported that the human 16p11.2 BP4-BP5 deletion and its associated dosage reduction caused CVMs. We aim to investigate the reciprocal 16p11.2 BP4-BP5 duplication and its potential genetic contributions to CVMs.

METHODS AND RESULTS: Patients who were found to carry the 16p11.2 BP4-BP5 duplication by chromosomal microarray analysis were retrospectively analysed for their vertebral phenotypes. The spinal assessments in seven duplication carriers showed that four (57\%) presented characteristics of CVMs, supporting the contention that increased dosage could induce CVMs. For further in vivo functional investigation in a model organism, we conducted genome editing of the upstream regulatory region of mouse using CRISPR-Cas9 and obtained three mouse mutant alleles ( to ) with elevated expression levels of . Luciferase reporter assays showed that the allele presented with the 160\% expression level of that observed in the reference (+) allele. Therefore, the homozygous mice could functionally mimic the dosage of heterozygous carriers of 16p11.2 BP4-BP5 duplication (approximately 150\%, ie, 3/2 gene dosage of the normal level). Remarkably, 60\% of the mice manifested with CVMs. Consistent with our observations in humans, the CVMs induced by increased dosage in mice mainly affected the cervical vertebrae.

CONCLUSION: Our findings in humans and mice consistently support that an increased dosage contributes to the risk of developing cervical CVMs.

}, issn = {1468-6244}, doi = {10.1136/jmedgenet-2019-106333}, author = {Ren, Xiaojun and Yang, Nan and Wu, Nan and Xu, Ximing and Chen, Weisheng and Zhang, Ling and Li, Yingping and Du, Ren-Qian and Dong, Shuangshuang and Zhao, Sen and Chen, Shuxia and Jiang, Li-Ping and Wang, Lianlei and Zhang, Jianguo and Wu, Zhihong and Jin, Li and Qiu, Guixing and Lupski, James R and Shi, Jiangang and Zhang, Feng and Liu, Pengfei} } @article {774, title = {TBX6 missense variants expand the mutational spectrum in a non-Mendelian inheritance disease.}, journal = {Hum Mutat}, volume = {41}, year = {2020}, month = {2020 01}, pages = {182-195}, abstract = {

Congenital scoliosis (CS) is a birth defect with variable clinical and anatomical manifestations due to spinal malformation. The genetic etiology underlying about 10\% of CS cases in the Chinese population is compound inheritance by which the gene dosage is reduced below that of haploinsufficiency. In this genetic model, the trait manifests as a result of the combined effect of a rare variant and common pathogenic variant allele at a locus. From exome sequencing (ES) data of 523 patients in Asia and two patients in Texas, we identified six TBX6 gene-disruptive variants from 11 unrelated CS patients via ES and in vitro functional testing. The in trans mild hypomorphic allele was identified in 10 of the 11 subjects; as anticipated these 10 shared a similar spinal deformity of hemivertebrae. The remaining case has a homozygous variant in TBX6 (c.418C>T) and presents a more severe spinal deformity phenotype. We found decreased transcriptional activity and abnormal cellular localization as the molecular mechanisms for TBX6 missense loss-of-function alleles. Expanding the mutational spectrum of TBX6 pathogenic alleles enabled an increased molecular diagnostic detection rate, provided further evidence for the gene dosage-dependent genetic model underlying CS, and refined clinical classification.

}, keywords = {Alleles, Cell Line, Female, Gene Expression, Genes, Reporter, Genetic Association Studies, Genetic Predisposition to Disease, Genotype, Haplotypes, Humans, Inheritance Patterns, Male, Models, Molecular, Molecular Diagnostic Techniques, Mutation, Missense, Phenotype, Protein Conformation, Radiography, Sequence Analysis, DNA, Spine, Structure-Activity Relationship, T-Box Domain Proteins, Whole Exome Sequencing}, issn = {1098-1004}, doi = {10.1002/humu.23907}, author = {Chen, Weisheng and Lin, Jiachen and Wang, Lianlei and Li, Xiaoxin and Zhao, Sen and Liu, Jiaqi and Akdemir, Zeynep C and Zhao, Yanxue and Du, Renqian and Ye, Yongyu and Song, Xiaofei and Zhang, Yuanqiang and Yan, Zihui and Yang, Xinzhuang and Lin, Mao and Shen, Jianxiong and Wang, Shengru and Gao, Na and Yang, Ying and Liu, Ying and Li, Wenli and Liu, Jia and Zhang, Na and Yang, Xu and Xu, Yuan and Zhang, Jianguo and Delgado, Mauricio R and Posey, Jennifer E and Qiu, Guixing and Rios, Jonathan J and Liu, Pengfei and Wise, Carol A and Zhang, Feng and Wu, Zhihong and Lupski, James R and Wu, Nan} }