@article {994, title = {Identification of homozygous mutations for hearing loss.}, journal = {Gene}, volume = {778}, year = {2021}, month = {2021 Apr 30}, pages = {145464}, abstract = {

BACKGROUND: Hearing loss is the most common sensory disorder worldwide, affecting about 1 out of every 1000 newborns. The disease has major genetic components, and can be inherited as a single gene disorder either in autosomal dominant or recessive fashions. Due to the high rate of consanguineous unions, Iran has one of the highest prevalence of autosomal recessive nonsyndromic deafness (ARNSD) in the world.

METHODS: We carried out a genetic screening of ten Iranian kindreds with more than one offspring affected by ARNSD caused by consanguineous unions. Sanger sequencing and whole exome sequencing together with in silico 3D structure modeling and protein stability prediction were used to identify the underlying disease causing genes.

CONCLUSION: We identified the causes of deafness in all 10 kindred. In six kindreds homozygous mutations were identified in GJB2 gene by Sanger sequencing. By using whole exome sequencing (WES), a homozygous missense mutation was identified in ESRRB gene as the first ever reported disease gene in Iran. Also two novel homozygous frameshift and missense mutations were identified in MYO15A gene and one previously reported mutation in TMC1 gene in three independent kindred. Our study shows the efficacy of WES for unraveling new pathogenic mutations in ARNSD patients and expands the spectrum of genes contributing to ARNSD in the Iranian population. The findings of our study can facilitate future genetic screening of patients with ARNSD , early screening and optimal design of novel therapeutics.

}, keywords = {Connexin 26, Consanguinity, Female, Frameshift Mutation, Genetic Predisposition to Disease, Hearing Loss, Homozygote, Humans, Iran, Male, Membrane Proteins, Models, Molecular, Mutation, Missense, Myosins, Pedigree, Protein Stability, Receptors, Estrogen, Whole Exome Sequencing}, issn = {1879-0038}, doi = {10.1016/j.gene.2021.145464}, author = {Dianatpour, Mehdi and Smith, Emily and Hashemi, Seyed Basir and Farazifard, Mohammad A and Nezafat, Navid and Razban, Vahid and Mani, Arya} } @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 = {

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.

}, 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 {349, title = {A postnatal role for embryonic myosin revealed by MYH3 mutations that alter TGFβ signaling and cause autosomal dominant spondylocarpotarsal synostosis.}, journal = {Sci Rep}, volume = {7}, year = {2017}, month = {2017 02 16}, pages = {41803}, abstract = {

Spondylocarpotarsal synostosis (SCT) is a skeletal disorder characterized by progressive vertebral, carpal and tarsal fusions, and mild short stature. The majority of affected individuals have an autosomal recessive form of SCT and are homozygous or compound heterozygous for nonsense mutations in the gene that encodes the cytoskeletal protein filamin B (FLNB), but a subset do not have FLNB mutations. Exome sequence analysis of three SCT patients negative for FLNB mutations identified an autosomal dominant form of the disease due to heterozygosity for missense or nonsense mutations in MYH3, which encodes embryonic myosin. Cells transfected with the MYH3 missense mutations had reduced TGFβ signaling, revealing a regulatory role for embryonic myosin in the TGFβ signaling pathway. In wild-type mice, there was persistent postnatal expression of embryonic myosin in the small muscles joining the neural arches of the spine suggesting that loss of myosin function in these muscles contribute to the disease. Our findings demonstrate that dominant mutations in MYH3 underlie autosomal dominant SCT, identify a postnatal role for embryonic myosin and suggest that altered regulation of signal transduction in the muscles within the spine may lead to the development of vertebral fusions.

}, keywords = {Abnormalities, Multiple, Alleles, Bone Morphogenetic Proteins, Cytoskeletal Proteins, Female, Genes, Dominant, Genotype, Humans, Lumbar Vertebrae, Male, Musculoskeletal Diseases, Mutation, Myosins, Phenotype, Radiography, Scoliosis, Signal Transduction, Synostosis, Thoracic Vertebrae, Transforming Growth Factor beta, Whole Exome Sequencing}, issn = {2045-2322}, doi = {10.1038/srep41803}, author = {Zieba, Jennifer and Zhang, Wenjuan and Chong, Jessica X and Forlenza, Kimberly N and Martin, Jorge H and Heard, Kelly and Grange, Dorothy K and Butler, Merlin G and Kleefstra, Tjitske and Lachman, Ralph S and Nickerson, Deborah and Regnier, Michael and Cohn, Daniel H and Bamshad, Michael and Krakow, Deborah} } @article {42, title = {Mutational Spectrum of MYO15A and the Molecular Mechanisms of DFNB3 Human Deafness.}, journal = {Hum Mutat}, volume = {37}, year = {2016}, month = {2016 10}, pages = {991-1003}, abstract = {

Deafness in humans is a common neurosensory disorder and is genetically heterogeneous. Across diverse ethnic groups, mutations of MYO15A at the DFNB3 locus appear to be the third or fourth most common cause of autosomal-recessive, nonsyndromic deafness. In 49 of the 67 exons of MYO15A, there are currently 192 recessive mutations identified, including 14 novel mutations reported here. These mutations are distributed uniformly across MYO15A with one enigmatic exception; the alternatively spliced giant exon 2, encoding 1,233 residues, has 17 truncating mutations but no convincing deafness-causing missense mutations. MYO15A encodes three distinct isoform classes, one of which is 395 kDa (3,530 residues), the largest member of the myosin superfamily of molecular motors. Studies of Myo15 mouse models that recapitulate DFNB3 revealed two different pathogenic mechanisms of hearing loss. In the inner ear, myosin 15 is necessary both for the development and the long-term maintenance of stereocilia, mechanosensory sound-transducing organelles that extend from the apical surface of hair cells. The goal of this Mutation Update is to provide a comprehensive review of mutations and functions of MYO15A.

}, keywords = {Alternative Splicing, Animals, Deafness, Disease Models, Animal, Ear, Inner, Exons, Gene Expression Regulation, Developmental, Humans, Mice, Mutation, Myosins, Stereocilia}, issn = {1098-1004}, doi = {10.1002/humu.23042}, author = {Rehman, Atteeq U and Bird, Jonathan E and Faridi, Rabia and Shahzad, Mohsin and Shah, Sujay and Lee, Kwanghyuk and Khan, Shaheen N and Imtiaz, Ayesha and Ahmed, Zubair M and Riazuddin, Saima and Santos-Cortez, Regie Lyn P and Ahmad, Wasim and Leal, Suzanne M and Riazuddin, Sheikh and Friedman, Thomas B} } @article {164, title = {Autosomal-Dominant Multiple Pterygium Syndrome Is Caused by Mutations in MYH3.}, journal = {Am J Hum Genet}, volume = {96}, year = {2015}, month = {2015 May 07}, pages = {841-9}, abstract = {

Multiple pterygium syndrome (MPS) is a phenotypically and genetically heterogeneous group of rare Mendelian conditions characterized by multiple pterygia, scoliosis, and congenital contractures of the limbs. MPS typically segregates as an autosomal-recessive disorder, but rare instances of autosomal-dominant transmission have been reported. Whereas several mutations causing recessive MPS have been identified, the genetic basis of dominant MPS remains unknown. We identified four families affected by dominantly transmitted MPS characterized by pterygia, camptodactyly of the hands, vertebral fusions, and scoliosis. Exome sequencing identified predicted protein-altering mutations in embryonic myosin heavy chain (MYH3) in three families. MYH3 mutations underlie distal arthrogryposis types 1, 2A, and 2B, but all mutations reported to date occur in the head and neck domains. In contrast, two of the mutations found to cause MPS in this study occurred in the tail domain. The phenotypic overlap among persons with MPS, coupled with physical findings distinct from other conditions caused by mutations in MYH3, suggests that the developmental mechanism underlying MPS differs from that of other conditions and/or that certain functions of embryonic myosin might be perturbed by disruption of specific residues and/or domains. Moreover, the vertebral fusions in persons with MPS, coupled with evidence of MYH3 expression in bone, suggest that embryonic myosin plays a role in skeletal development.

}, keywords = {Arthrogryposis, Cytoskeletal Proteins, Exome, Genetic Predisposition to Disease, High-Throughput Nucleotide Sequencing, Humans, Mutation, Myosins, Osteogenesis}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2015.04.004}, author = {Chong, Jessica X and Burrage, Lindsay C and Beck, Anita E and Marvin, Colby T and McMillin, Margaret J and Shively, Kathryn M and Harrell, Tanya M and Buckingham, Kati J and Bacino, Carlos A and Jain, Mahim and Alanay, Yasemin and Berry, Susan A and Carey, John C and Gibbs, Richard A and Lee, Brendan H and Krakow, Deborah and Shendure, Jay and Nickerson, Deborah A and Bamshad, Michael J} }