@article {500,
	title = {Genetic variants in components of the NALCN-UNC80-UNC79 ion channel complex cause a broad clinical phenotype (NALCN channelopathies).},
	journal = {Hum Genet},
	volume = {137},
	year = {2018},
	month = {2018 Sep},
	pages = {753-768},
	abstract = {<p>NALCN is a conserved cation channel, which conducts a permanent sodium leak current and regulates resting membrane potential and neuronal excitability. It is part of a large ion channel complex, the "NALCN channelosome", consisting of multiple proteins including UNC80 and UNC79. The predominant neuronal expression pattern and its function suggest an important role in neuronal function and disease. So far, biallelic NALCN and UNC80 variants have been described in a small number of individuals leading to infantile hypotonia, psychomotor retardation, and characteristic facies 1 (IHPRF1, OMIM 615419) and 2 (IHPRF2, OMIM 616801), respectively. Heterozygous de novo NALCN missense variants in the S5/S6 pore-forming segments lead to congenital contractures of the limbs and face, hypotonia, and developmental delay (CLIFAHDD, OMIM 616266) with some clinical overlap. In this study, we present detailed clinical information of 16 novel individuals with biallelic NALCN variants, 1 individual with a heterozygous de novo NALCN missense variant and an interesting clinical phenotype without contractures, and 12 individuals with biallelic UNC80 variants. We report for the first time a missense NALCN variant~located in the predicted S6 pore-forming unit inherited in an autosomal-recessive manner leading to mild IHPRF1. We show evidence of clinical variability, especially among IHPRF1-affected individuals, and discuss differences between the IHPRF1- and IHPRF2 phenotypes. In summary, we provide a comprehensive overview of IHPRF1 and IHPRF2 phenotypes based on the largest cohort of individuals reported so far and provide additional insights into the clinical phenotypes of these neurodevelopmental diseases to help improve counseling of affected families.</p>},
	keywords = {Adolescent, Adult, Carrier Proteins, Channelopathies, Child, Child, Preschool, Developmental Disabilities, Female, Genetic Markers, Genetic Variation, Humans, Infant, Infant, Newborn, Male, Membrane Proteins, Phenotype, Sodium Channels, Young Adult},
	issn = {1432-1203},
	doi = {10.1007/s00439-018-1929-5},
	author = {Bramswig, Nuria C and Bertoli-Avella, Aida M and Albrecht, Beate and Al Aqeel, Aida I and Alhashem, Amal and Al-Sannaa, Nouriya and Bah, Maissa and Br{\"o}hl, Katharina and Depienne, Christel and Dorison, Nathalie and Doummar, Diane and Ehmke, Nadja and Elbendary, Hasnaa M and Gorokhova, Svetlana and H{\'e}ron, Delphine and Horn, Denise and James, Kiely and Keren, Boris and Kuechler, Alma and Ismail, Samira and Issa, Mahmoud Y and Marey, Isabelle and Mayer, Mich{\`e}le and McEvoy-Venneri, Jennifer and Megarbane, Andre and Mignot, Cyril and Mohamed, Sarar and Nava, Caroline and Philip, Nicole and Ravix, Cecile and Rolfs, Arndt and Sadek, Abdelrahim Abdrabou and Segebrecht, Lara and Stanley, Valentina and Trautman, Camille and Valence, Stephanie and Villard, Laurent and Wieland, Thomas and Engels, Hartmut and Strom, Tim M and Zaki, Maha S and Gleeson, Joseph G and L{\"u}decke, Hermann-Josef and Bauer, Peter and Wieczorek, Dagmar}
}
@article {194,
	title = {De novo mutations in NALCN cause a syndrome characterized by congenital contractures of the limbs and face, hypotonia, and developmental delay.},
	journal = {Am J Hum Genet},
	volume = {96},
	year = {2015},
	month = {2015 Mar 05},
	pages = {462-73},
	abstract = {<p>Freeman-Sheldon syndrome, or distal arthrogryposis type 2A (DA2A), is an autosomal-dominant condition caused by mutations in MYH3 and characterized by multiple congenital contractures of the face and limbs and normal cognitive development. We identified a subset of five individuals who had been putatively diagnosed with "DA2A with severe neurological abnormalities" and for whom congenital contractures of the limbs and face, hypotonia, and global developmental delay had resulted in early death in three cases; this is a unique condition that we now refer to as CLIFAHDD syndrome. Exome sequencing identified missense mutations in the sodium leak channel, non-selective (NALCN) in four families affected by CLIFAHDD syndrome. We used molecular-inversion probes to screen for NALCN in a cohort of 202 distal arthrogryposis (DA)-affected individuals as well as concurrent exome sequencing of six other DA-affected individuals, thus revealing NALCN mutations in ten additional families with "atypical" forms of DA. All 14 mutations were missense variants predicted to alter amino acid residues in or near the S5 and S6 pore-forming segments of NALCN, highlighting the functional importance of these segments. In vitro functional studies demonstrated that NALCN alterations nearly abolished the expression of wild-type NALCN, suggesting that alterations that cause CLIFAHDD syndrome have a dominant-negative effect. In contrast, homozygosity for mutations in other regions of NALCN has been reported in three families affected by an autosomal-recessive condition characterized mainly by hypotonia and severe intellectual disability. Accordingly, mutations in NALCN can cause either a recessive or dominant condition characterized by varied though overlapping phenotypic features, perhaps based on the type of mutation and affected protein domain(s).</p>},
	keywords = {Arthrogryposis, Contracture, Craniofacial Dysostosis, Cytoskeletal Proteins, Exome, Extremities, Face, Female, Gene Frequency, High-Throughput Nucleotide Sequencing, Homozygote, Humans, Infant, Male, Muscle Hypotonia, Mutation, Missense, Sodium Channels},
	issn = {1537-6605},
	doi = {10.1016/j.ajhg.2015.01.003},
	author = {Chong, Jessica X and McMillin, Margaret J and Shively, Kathryn M and Beck, Anita E and Marvin, Colby T and Armenteros, Jose R and Buckingham, Kati J and Nkinsi, Naomi T and Boyle, Evan A and Berry, Margaret N and Bocian, Maureen and Foulds, Nicola and Uzielli, Maria Luisa Giovannucci and Haldeman-Englert, Chad and Hennekam, Raoul C M and Kaplan, Paige and Kline, Antonie D and Mercer, Catherine L and Nowaczyk, Malgorzata J M and Klein Wassink-Ruiter, Jolien S and McPherson, Elizabeth W and Moreno, Regina A and Scheuerle, Angela E and Shashi, Vandana and Stevens, Cathy A and Carey, John C and Monteil, Arnaud and Lory, Philippe and Tabor, Holly K and Smith, Joshua D and Shendure, Jay and Nickerson, Deborah A and Bamshad, Michael J}
}
