@article {779,
	title = {Bi-allelic ADARB1 Variants Associated with Microcephaly, Intellectual Disability, and Seizures.},
	journal = {Am J Hum Genet},
	volume = {106},
	year = {2020},
	month = {2020 04 02},
	pages = {467-483},
	abstract = {<p>The RNA editing enzyme ADAR2 is essential for the recoding of brain transcripts. Impaired ADAR2 editing leads to early-onset epilepsy and premature death in a mouse model. Here, we report bi-allelic variants in ADARB1, the gene encoding ADAR2, in four unrelated individuals with microcephaly, intellectual disability, and epilepsy. In one individual, a homozygous variant in one of the double-stranded RNA-binding domains (dsRBDs) was identified. In the others, variants were situated in or around the deaminase domain. To evaluate the effects of these variants on ADAR2 enzymatic activity, we performed in~vitro assays with recombinant proteins in HEK293T cells and ex~vivo assays with fibroblasts derived from one of the individuals. We demonstrate that these ADAR2 variants lead to reduced editing activity on a known ADAR2 substrate. We also demonstrate that one variant leads to changes in splicing of ADARB1 transcript isoforms. These findings reinforce the importance of RNA editing in brain development and introduce ADARB1 as a genetic etiology in individuals with intellectual disability, microcephaly, and epilepsy.</p>},
	keywords = {Adenosine Deaminase, Alleles, Alternative Splicing, Child, Child, Preschool, Genetic Predisposition to Disease, Genetic Variation, HEK293 Cells, Humans, Intellectual Disability, Male, Microcephaly, RNA Splicing, RNA-Binding Proteins, Seizures},
	issn = {1537-6605},
	doi = {10.1016/j.ajhg.2020.02.015},
	author = {Tan, Tiong Yang and Sedm{\'\i}k, Ji{\v r}{\'\i} and Fitzgerald, Mark P and Halevy, Rivka Sukenik and Keegan, Liam P and Helbig, Ingo and Basel-Salmon, Lina and Cohen, Lior and Straussberg, Rachel and Chung, Wendy K and Helal, Mayada and Maroofian, Reza and Houlden, Henry and Juusola, Jane and Sadedin, Simon and Pais, Lynn and Howell, Katherine B and White, Susan M and Christodoulou, John and O{\textquoteright}Connell, Mary A}
}
@article {962,
	title = {Bi-allelic Variations of SMO in Humans Cause a Broad Spectrum of Developmental Anomalies Due to Abnormal Hedgehog Signaling.},
	journal = {Am J Hum Genet},
	volume = {106},
	year = {2020},
	month = {2020 06 04},
	pages = {779-792},
	abstract = {<p>The evolutionarily conserved hedgehog (Hh) pathway is essential for organogenesis and plays critical roles in postnatal tissue maintenance and renewal. A unique feature of the vertebrate Hh pathway is that signal transduction requires the primary cilium (PC) where major pathway components are dynamically enriched. These factors include smoothened (SMO) and patched, which constitute the core reception system for sonic hedgehog (SHH) as well as GLI transcription factors, the key mediators of the pathway. Here, we report bi-allelic loss-of-function variations in SMO in seven individuals from five independent families; these variations cause a wide phenotypic spectrum of developmental anomalies affecting the brain (hypothalamic hamartoma and microcephaly), heart (atrioventricular septal defect), skeleton (postaxial polydactyly, narrow chest, and shortening of long bones), and enteric nervous system (aganglionosis). Cells derived from affected individuals showed normal ciliogenesis but severely altered Hh-signal transduction as a result of either altered PC trafficking or abnormal activation of the pathway downstream of SMO. In addition, Hh-independent GLI2 accumulation at the PC tip in cells from the affected individuals suggests a potential function of SMO in regulating basal ciliary trafficking of GLI2 when the pathway is off. Thus, loss of SMO function results in abnormal PC dynamics of key components of the Hh signaling pathway and leads to a large continuum of malformations in humans.</p>},
	keywords = {Alleles, Base Sequence, Child, Child, Preschool, Cilia, Developmental Disabilities, Female, Hedgehog Proteins, Humans, Infant, Male, Models, Molecular, Neoplasms, Nerve Tissue Proteins, Nuclear Proteins, Pedigree, Signal Transduction, Smoothened Receptor, Zinc Finger Protein Gli2, Zinc Finger Protein Gli3},
	issn = {1537-6605},
	doi = {10.1016/j.ajhg.2020.04.010},
	author = {Le, Thuy-Linh and Sribudiani, Yunia and Dong, Xiaomin and Huber, Celine and Kois, Chelsea and Baujat, Genevi{\`e}ve and Gordon, Christopher T and Mayne, Valerie and Galmiche, Louise and Serre, Val{\'e}rie and Goudin, Nicolas and Zarhrate, Mohammed and Bole-Feysot, Christine and Masson, Cecile and Nitschk{\'e}, Patrick and Verheijen, Frans W and Pais, Lynn and Pelet, Anna and Sadedin, Simon and Pugh, John A and Shur, Natasha and White, Susan M and El Chehadeh, Salima and Christodoulou, John and Cormier-Daire, Val{\'e}rie and Hofstra, R M W and Lyonnet, Stanislas and Tan, Tiong Yang and Atti{\'e}-Bitach, Tania and Kerstjens-Frederikse, Wilhelmina S and Amiel, Jeanne and Thomas, Sophie}
}
