@article {814,
	title = {Mutations in MYLPF Cause a Novel Segmental Amyoplasia that Manifests as Distal Arthrogryposis.},
	journal = {Am J Hum Genet},
	volume = {107},
	year = {2020},
	month = {2020 08 06},
	pages = {293-310},
	abstract = {<p>We identified ten persons in six consanguineous families with distal arthrogryposis (DA) who had congenital contractures, scoliosis, and short stature. Exome sequencing revealed that each affected person was homozygous for one of two different rare variants (c.470G>T [p.Cys157Phe] or c.469T>C [p.Cys157Arg]) affecting the same residue of myosin light chain, phosphorylatable, fast skeletal muscle (MYLPF). In a seventh family, a c.487G>A (p.Gly163Ser) variant in MYLPF arose de novo in a father, who transmitted it to his son. In an eighth family comprised of seven individuals with dominantly inherited DA, a c.98C>T (p.Ala33Val) variant segregated in all four persons tested. Variants in MYLPF underlie both dominant and recessively inherited DA. Mylpf protein models suggest that the residues associated with dominant DA interact with myosin whereas the residues altered in families with recessive DA only indirectly impair this interaction. Pathological and histological exam of a foot amputated from an affected child revealed complete absence of skeletal muscle (i.e., segmental amyoplasia). To investigate the mechanism for this finding, we generated an animal model for partial MYLPF impairment by knocking out zebrafish mylpfa. The mylpfa mutant had reduced trunk contractile force and complete pectoral fin paralysis, demonstrating that mylpf impairment most severely affects limb movement. mylpfa mutant muscle weakness was most pronounced in an appendicular muscle and was explained by reduced myosin activity and fiber degeneration. Collectively, our findings demonstrate that partial loss of MYLPF function can lead to congenital contractures, likely as a result of degeneration of skeletal muscle in the distal limb.</p>},
	keywords = {Adolescent, Amino Acid Sequence, Animals, Arthrogryposis, Child, Contracture, Extremities, Female, Humans, Male, Muscle, Skeletal, Musculoskeletal Abnormalities, Mutation, Myosin Light Chains, Myosins, Pedigree, Young Adult, Zebrafish},
	issn = {1537-6605},
	doi = {10.1016/j.ajhg.2020.06.014},
	author = {Chong, Jessica X and Talbot, Jared C and Teets, Emily M and Previs, Samantha and Martin, Brit L and Shively, Kathryn M and Marvin, Colby T and Aylsworth, Arthur S and Saadeh-Haddad, Reem and Schatz, Ulrich A and Inzana, Francesca and Ben-Omran, Tawfeg and Almusafri, Fatima and Al-Mulla, Mariam and Buckingham, Kati J and Harel, Tamar and Mor-Shaked, Hagar and Radhakrishnan, Periyasamy and Girisha, Katta M and Nayak, Shalini S and Shukla, Anju and Dieterich, Klaus and Faure, Julien and Rendu, John and Capri, Yline and Latypova, X{\'e}nia and Nickerson, Deborah A and Warshaw, David M and Janssen, Paul M L and Amacher, Sharon L and Bamshad, Michael J}
}
@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}
}
