Maedeh Mohebnasab

Dr. Maedeh Mohebnasab

Pathology, UPMC Presbyterian, Pittsburgh, Pennsylvania, USA
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Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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9 October 2015 in Nature Communications
Verified
Journal Article
Open access
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YLYun Li
Yun Li
SZSihai D. Zhao
Sihai D. Zhao
JLJin Li
Jin Li
JBJonathan P. Bradfield
Jonathan P. Bradfield
Maedeh MohebnasabMaedeh Mohebnasab
Maedeh Mohebnasab
HHHakon Hakonarson
Hakon Hakonarson
Autoimmune diseases (AIDs) are polygenic diseases affecting 7–10% of the population in the Western Hemisphere with few effective therapies. Here, we quantify the heritability of paediatric AIDs (pAIDs), including JIA, SLE, CEL, T1D, UC, CD, PS, SPA and CVID, attributable to common genomic variations (SNP-h2). SNP-h2 estimates are most significant for T1D (0.863±s.e. 0.07) and JIA (0.727±s.e. 0.037), more modest for UC (0.386±s.e. 0.04) and CD (0.454±0.025), largely consistent with population estimates and are generally greater than that previously reported by adult GWAS. On pairwise analysis, we observed that the diseases UC-CD (0.69±s.e. 0.07) and JIA-CVID (0.343±s.e. 0.13) are the most strongly correlated. Variations across the MHC strongly contribute to SNP-h2 in T1D and JIA, but does not significantly contribute to the pairwise rG. Together, our results partition contributions of shared versus disease-specific genomic variations to pAID heritability, identifying pAIDs with unexpected risk sharing, while recapitulating known associations between autoimmune diseases previously reported in adult cohorts.

14 January 2020 in Nature Communications
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Journal Article
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YLYun Li
Yun Li
JGJoseph T. Glessner
Joseph T. Glessner
BCBradley P. Coe
Bradley P. Coe
JLJin Li
Jin Li
Maedeh MohebnasabMaedeh Mohebnasab
Maedeh Mohebnasab
HHHakon Hakonarson
Hakon Hakonarson
Copy number variants (CNVs) are suggested to have a widespread impact on the human genome and phenotypes. To understand the role of CNVs across human diseases, we examine the CNV genomic landscape of 100,028 unrelated individuals of European ancestry, using SNP and CGH array datasets. We observe an average CNV burden of ~650 kb, identifying a total of 11,314 deletion, 5625 duplication, and 2746 homozygous deletion CNV regions (CNVRs). In all, 13.7% are unreported, 58.6% overlap with at least one gene, and 32.8% interrupt coding exons. These CNVRs are significantly more likely to overlap OMIM genes (2.94-fold), GWAS loci (1.52-fold), and non-coding RNAs (1.44-fold), compared with random distribution (P < 1 × 10−3). We uncover CNV associations with four major disease categories, including autoimmune, cardio-metabolic, oncologic, and neurological/psychiatric diseases, and identify several drug-repurposing opportunities. Our results demonstrate robust frequency definition for large-scale rare variant association studies, identify CNVs associated with major disease categories, and illustrate the pleiotropic impact of CNVs in human disease.

17 May 2024 in Nature Medicine
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ESEloi Schmauch
Eloi Schmauch
Brian PieningBrian Piening
Brian Piening
Maedeh MohebnasabMaedeh Mohebnasab
Maedeh Mohebnasab
BXBo Xia
Bo Xia
CZChenchen Zhu
Chenchen Zhu
BKBrendan J. Keating
Brendan J. Keating

1 November 2015 in Transplantation
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Journal Article
Open access
Maedeh MohebnasabMaedeh Mohebnasab
Maedeh Mohebnasab
Background Genetic association studies of transplantation outcomes have been hampered by small samples and highly complex multifactorial phenotypes, hindering investigations of the genetic architecture of a range of comorbidities which significantly impact graft and recipient life expectancy. We describe here the rationale and design of the International Genetics & Translational Research in Transplantation Network. The network comprises 22 studies to date, including 16494 transplant recipients and 11669 donors, of whom more than 5000 are of non-European ancestry, all of whom have existing genomewide genotype data sets. Methods We describe the rich genetic and phenotypic information available in this consortium comprising heart, kidney, liver, and lung transplant cohorts. Results We demonstrate significant power in International Genetics & Translational Research in Transplantation Network to detect main effect association signals across regions such as the MHC region as well as genomewide for transplant outcomes that span all solid organs, such as graft survival, acute rejection, new onset of diabetes after transplantation, and for delayed graft function in kidney only. Conclusions This consortium is designed and statistically powered to deliver pioneering insights into the genetic architecture of transplant-related outcomes across a range of different solid-organ transplant studies. The study design allows a spectrum of analyses to be performed including recipient-only analyses, donor-recipient HLA mismatches with focus on loss-of-function variants and nonsynonymous single nucleotide polymorphisms.

1 October 2015 in Genome Medicine
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YLYun Li
Yun Li
JSJessica van Setten
Jessica van Setten
SVShefali S. Verma
Shefali S. Verma
YLYontao Lu
Yontao Lu
MHMichael V. Holmes
Michael V. Holmes
BKBrendan J. Keating
Brendan J. Keating
In addition to HLA genetic incompatibility, non-HLA difference between donor and recipients of transplantation leading to allograft rejection are now becoming evident. We aimed to create a unique genome-wide platform to facilitate genomic research studies in transplant-related studies. We designed a genome-wide genotyping tool based on the most recent human genomic reference datasets, and included customization for known and potentially relevant metabolic and pharmacological loci relevant to transplantation. We describe here the design and implementation of a customized genome-wide genotyping array, the ‘TxArray’, comprising approximately 782,000 markers with tailored content for deeper capture of variants across HLA, KIR, pharmacogenomic, and metabolic loci important in transplantation. To test concordance and genotyping quality, we genotyped 85 HapMap samples on the array, including eight trios. We show low Mendelian error rates and high concordance rates for HapMap samples (average parent-parent-child heritability of 0.997, and concordance of 0.996). We performed genotype imputation across autosomal regions, masking directly genotyped SNPs to assess imputation accuracy and report an accuracy of >0.962 for directly genotyped SNPs. We demonstrate much higher capture of the natural killer cell immunoglobulin-like receptor (KIR) region versus comparable platforms. Overall, we show that the genotyping quality and coverage of the TxArray is very high when compared to reference samples and to other genome-wide genotyping platforms. We have designed a comprehensive genome-wide genotyping tool which enables accurate association testing and imputation of ungenotyped SNPs, facilitating powerful and cost-effective large-scale genotyping of transplant-related studies.

9 August 2018 in JCI Insight
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Alison K. BauerAlison K. Bauer
Alison K. Bauer
MUMisha Umer
Misha Umer
VRVanessa L. Richardson
Vanessa L. Richardson
ACAmber M. Cumpian
Amber M. Cumpian
AHAnna Q. Harder
Anna Q. Harder
Seyed Javad MoghaddamSeyed Javad Moghaddam
Seyed Javad Moghaddam
With more than 150,000 deaths per year in the US alone, lung cancer has the highest number of deaths for any cancer. These poor outcomes reflect a lack of treatment for the most common form of lung cancer, non–small cell lung carcinoma (NSCLC). Lung adenocarcinoma (ADC) is the most prevalent subtype of NSCLC, with the main oncogenic drivers being KRAS and epidermal growth factor receptor (EGFR). Whereas EGFR blockade has led to some success in lung ADC, effective KRAS inhibition is lacking. KRAS-mutant ADCs are characterized by high levels of gel-forming mucin expression, with the highest mucin levels corresponding to worse prognoses. Despite these well-recognized associations, little is known about roles for individual gel-forming mucins in ADC development causatively. We hypothesized that MUC5AC / Muc5ac , a mucin gene known to be commonly expressed in NSCLC, is crucial in KRAS / Kras -driven lung ADC. We found that MUC5AC was a significant determinant of poor prognosis, especially in patients with KRAS -mutant tumors. In addition, by using mice with lung ADC induced chemically with urethane or transgenically by mutant- Kras expression, we observed significantly reduced tumor development in animals lacking Muc5ac compared with controls. Collectively, these results provide strong support for MUC5AC as a potential therapeutic target for lung ADC, a disease with few effective treatments.