@article {963, title = {Absent B cells, agammaglobulinemia, and hypertrophic cardiomyopathy in folliculin-interacting protein 1 deficiency.}, journal = {Blood}, volume = {137}, year = {2021}, month = {2021 01 28}, pages = {493-499}, abstract = {

Agammaglobulinemia is the most profound primary antibody deficiency that can occur due to an early termination of B-cell development. We here investigated 3 novel patients, including the first known adult, from unrelated families with agammaglobulinemia, recurrent infections, and hypertrophic cardiomyopathy (HCM). Two of them also presented with intermittent or severe chronic neutropenia. We identified homozygous or compound-heterozygous variants in the gene for folliculin interacting protein 1 (FNIP1), leading to loss of the FNIP1 protein. B-cell metabolism, including mitochondrial numbers and activity and phosphatidylinositol 3-kinase/AKT pathway, was impaired. These defects recapitulated the Fnip1-/- animal model. Moreover, we identified either uniparental disomy or copy-number variants (CNVs) in 2 patients, expanding the variant spectrum of this novel inborn error of immunity. The results indicate that FNIP1 deficiency can be caused by complex genetic mechanisms and support the clinical utility of exome sequencing and CNV analysis in patients with broad phenotypes, including agammaglobulinemia and HCM. FNIP1 deficiency is a novel inborn error of immunity characterized by early and severe B-cell development defect, agammaglobulinemia, variable neutropenia, and HCM. Our findings elucidate a functional and relevant role of FNIP1 in B-cell development and metabolism and potentially neutrophil activity.

}, keywords = {Adult, Agammaglobulinemia, Animals, B-Lymphocytes, Cardiomyopathy, Hypertrophic, Carrier Proteins, Child, Child, Preschool, Chromosomes, Human, Pair 5, Codon, Nonsense, Consanguinity, Crohn Disease, Developmental Disabilities, Disease Models, Animal, Disease Susceptibility, DNA Copy Number Variations, Female, Heart Defects, Congenital, Humans, Immunologic Deficiency Syndromes, Infections, Loss of Function Mutation, Lymphopenia, Male, Mice, Neutropenia, Pedigree, Uniparental Disomy, Whole Exome Sequencing}, issn = {1528-0020}, doi = {10.1182/blood.2020006441}, author = {Saettini, Francesco and Poli, Cecilia and Vengoechea, Jaime and Bonanomi, Sonia and Orellana, Julio C and Fazio, Grazia and Rodriguez, Fred H and Noguera, Loreani P and Booth, Claire and Jarur-Chamy, Valentina and Shams, Marissa and Iascone, Maria and Vukic, Maja and Gasperini, Serena and Quadri, Manuel and Barroeta Seijas, Amairelys and Rivers, Elizabeth and Mauri, Mario and Badolato, Raffaele and Cazzaniga, Gianni and Bugarin, Cristina and Gaipa, Giuseppe and Kroes, Wilma G M and Moratto, Daniele and van Oostaijen-Ten Dam, Monique M and Baas, Frank and van der Maarel, Silv{\`e}re and Piazza, Rocco and Coban-Akdemir, Zeynep H and Lupski, James R and Yuan, Bo and Chinn, Ivan K and Daxinger, Lucia and Biondi, Andrea} } @article {761, title = {Wolff-Parkinson-White syndrome: De novo variants and evidence for mutational burden in genes associated with atrial fibrillation.}, journal = {Am J Med Genet A}, volume = {182}, year = {2020}, month = {2020 06}, pages = {1387-1399}, abstract = {

BACKGROUND: Wolff-Parkinson-White (WPW) syndrome is a relatively common arrhythmia affecting ~1-3/1,000 individuals. Mutations in PRKAG2 have been described in rare patients in association with cardiomyopathy. However, the genetic basis of WPW in individuals with a structurally normal heart remains poorly understood. Sudden death due to atrial fibrillation (AF) can also occur in these individuals. Several studies have indicated that despite ablation of an accessory pathway, the risk of AF remains high in patients compared to general population.

METHODS: We applied exome sequencing in 305 subjects, including 65 trios, 80 singletons, and 6 multiple affected families. We used de novo analysis, candidate gene approach, and burden testing to explore the genetic contributions to WPW.

RESULTS: A heterozygous deleterious variant in PRKAG2 was identified in one subject, accounting for 0.6\% (1/151) of the genetic basis of WPW in this study. Another individual with WPW and left ventricular hypertrophy carried a known pathogenic variant in MYH7. We found rare de novo variants in genes associated with arrhythmia and cardiomyopathy (ANK2, NEBL, PITX2, and PRDM16) in this cohort. There was an increased burden of rare deleterious variants (MAF <= 0.005) with CADD score >= 25 in genes linked to AF in cases compared to controls (P = .0023).

CONCLUSIONS: Our findings show an increased burden of rare deleterious variants in genes linked to AF in WPW syndrome, suggesting that genetic factors that determine the development of accessory pathways may be linked to an increased susceptibility of atrial muscle to AF in a subset of patients.

}, keywords = {Adolescent, Adult, AMP-Activated Protein Kinases, Ankyrins, Atrial Fibrillation, Carrier Proteins, Child, Cohort Studies, Cytoskeletal Proteins, DNA-Binding Proteins, Female, Genetic Association Studies, Genetic Predisposition to Disease, Heart Atria, Homeodomain Proteins, Humans, LIM Domain Proteins, Male, Mutation, Transcription Factors, Whole Exome Sequencing, Wolff-Parkinson-White Syndrome, Young Adult}, issn = {1552-4833}, doi = {10.1002/ajmg.a.61571}, author = {Coban-Akdemir, Zeynep H and Charng, Wu-Lin and Azamian, Mahshid and Paine, Ingrid S and Punetha, Jaya and Grochowski, Christopher M and Gambin, Tomasz and Valdes, Santiago O and Cannon, Bryan and Zapata, Gladys and Hernandez, Patricia P and Jhangiani, Shalini and Doddapaneni, Harsha and Hu, Jianhong and Boricha, Fatima and Muzny, Donna M and Boerwinkle, Eric and Yang, Yaping and Gibbs, Richard A and Posey, Jennifer E and Wehrens, Xander H T and Belmont, John W and Kim, Jeffrey J and Miyake, Christina Y and Lupski, James R and Lalani, Seema R} }