Department of Medical and Molecular Genetics Works

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Browsing Department of Medical and Molecular Genetics Works by Subject "22q13"

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    De novo and inherited TCF20 pathogenic variants are associated with intellectual disability, dysmorphic features, hypotonia, and neurological impairments with similarities to Smith-Magenis syndrome
    (BMC, 2019-02-28) Vetrini, Francesco; McKee, Shane; Rosenfeld, Jill A.; Suri, Mohnish; Lewis, Andrea M.; Nugent, Kimberly Margaret; Roeder, Elizabeth; Littlejohn, Rebecca O.; Holder, Sue; Zhu, Wenmiao; Alaimo, Joseph T.; Graham, Brett; Harris, Jill M.; Gibson, James B.; Pastore, Matthew; McBride, Kim L.; Komara, Makanko; Al-Gazali, Lihadh; Al Shamsi, Aisha; Fanning, Elizabeth A.; Wierenga, Klaas J.; Scott, Daryl A.; Ben-Neriah, Ziva; Meiner, Vardiella; Cassuto, Hanoch; Elpeleg, Orly; Holder, J. Lloyd, Jr.; Burrage, Lindsay C.; Seaver, Laurie H.; Van Maldergem, Lionel; Mahida, Sonal; Soul, Janet S.; Marlatt, Margaret; Matyakhina, Ludmila; Vogt, Julie; Gold, June-Anne; Park, Soo-Mi; Varghese, Vinod; Lampe, Anne K.; Kumar, Ajith; Lees, Melissa; Holder-Espinasse, Muriel; McConnell, Vivienne; Bernhard, Birgitta; Blair, Ed; Harrison, Victoria; The DDD study; Muzny, Donna M.; Gibbs, Richard A.; Elsea, Sarah H.; Posey, Jennifer E.; Bi, Weimin; Lalani, Seema; Xia, Fan; Yang, Yaping; Eng, Christine M.; Lupski, James R.; Liu, Pengfei; Medical and Molecular Genetics, School of Medicine
    BACKGROUND: Neurodevelopmental disorders are genetically and phenotypically heterogeneous encompassing developmental delay (DD), intellectual disability (ID), autism spectrum disorders (ASDs), structural brain abnormalities, and neurological manifestations with variants in a large number of genes (hundreds) associated. To date, a few de novo mutations potentially disrupting TCF20 function in patients with ID, ASD, and hypotonia have been reported. TCF20 encodes a transcriptional co-regulator structurally related to RAI1, the dosage-sensitive gene responsible for Smith-Magenis syndrome (deletion/haploinsufficiency) and Potocki-Lupski syndrome (duplication/triplosensitivity). METHODS: Genome-wide analyses by exome sequencing (ES) and chromosomal microarray analysis (CMA) identified individuals with heterozygous, likely damaging, loss-of-function alleles in TCF20. We implemented further molecular and clinical analyses to determine the inheritance of the pathogenic variant alleles and studied the spectrum of phenotypes. RESULTS: We report 25 unique inactivating single nucleotide variants/indels (1 missense, 1 canonical splice-site variant, 18 frameshift, and 5 nonsense) and 4 deletions of TCF20. The pathogenic variants were detected in 32 patients and 4 affected parents from 31 unrelated families. Among cases with available parental samples, the variants were de novo in 20 instances and inherited from 4 symptomatic parents in 5, including in one set of monozygotic twins. Two pathogenic loss-of-function variants were recurrent in unrelated families. Patients presented with a phenotype characterized by developmental delay, intellectual disability, hypotonia, variable dysmorphic features, movement disorders, and sleep disturbances. CONCLUSIONS: TCF20 pathogenic variants are associated with a novel syndrome manifesting clinical characteristics similar to those observed in Smith-Magenis syndrome. Together with previously described cases, the clinical entity of TCF20-associated neurodevelopmental disorders (TAND) emerges from a genotype-driven perspective.