@article {451, title = {Congenital Titinopathy: Comprehensive characterization and pathogenic insights.}, journal = {Ann Neurol}, volume = {83}, year = {2018}, month = {2018 Jun}, pages = {1105-1124}, abstract = {

OBJECTIVE: Comprehensive clinical characterization of congenital titinopathy to facilitate diagnosis and management of this important emerging disorder.

METHODS: Using massively parallel sequencing we identified 30 patients from 27 families with 2 pathogenic nonsense, frameshift and/or splice site TTN mutations in trans. We then undertook a detailed analysis of the clinical, histopathological and imaging features of these patients.

RESULTS: All patients had prenatal or early onset hypotonia and/or congenital contractures. None had ophthalmoplegia. Scoliosis and respiratory insufficiency typically developed early and progressed rapidly, whereas limb weakness was often slowly progressive, and usually did not prevent independent walking. Cardiac involvement was present in 46\% of patients. Relatives of 2 patients had dilated cardiomyopathy. Creatine kinase levels were normal to moderately elevated. Increased fiber size variation, internalized nuclei and cores were common histopathological abnormalities. Cap-like regions, whorled or ring fibers, and mitochondrial accumulations were also observed. Muscle magnetic resonance imaging showed gluteal, hamstring and calf muscle involvement. Western blot analysis showed a near-normal sized titin protein in all samples. The presence of 2 mutations predicted to impact both N2BA and N2B cardiac isoforms appeared to be associated with greatest risk of cardiac involvement. One-third of patients had 1 mutation predicted to impact exons present in fetal skeletal muscle, but not included within the mature skeletal muscle isoform transcript. This strongly suggests developmental isoforms are involved in the pathogenesis of this congenital/early onset disorder.

INTERPRETATION: This detailed clinical reference dataset will greatly facilitate diagnostic confirmation and management of patients, and has provided important insights into disease pathogenesis. Ann Neurol 2018;83:1105-1124.

}, issn = {1531-8249}, doi = {10.1002/ana.25241}, author = {Oates, Emily C and Jones, Kristi J and Donkervoort, Sandra and Charlton, Amanda and Brammah, Susan and Smith, John E and Ware, James S and Yau, Kyle S and Swanson, Lindsay C and Whiffin, Nicola and Peduto, Anthony J and Bournazos, Adam and Waddell, Leigh B and Farrar, Michelle A and Sampaio, Hugo A and Teoh, Hooi Ling and Lamont, Phillipa J and Mowat, David and Fitzsimons, Robin B and Corbett, Alastair J and Ryan, Monique M and O{\textquoteright}Grady, Gina L and Sandaradura, Sarah A and Ghaoui, Roula and Joshi, Himanshu and Marshall, Jamie L and Nolan, Melinda A and Kaur, Simranpreet and Punetha, Jaya and Topf, Ana and Harris, Elizabeth and Bakshi, Madhura and Genetti, Casie A and Marttila, Minttu and Werlauff, Ulla and Streichenberger, Nathalie and Pestronk, Alan and Mazanti, Ingrid and Pinner, Jason R and Vuillerot, Carole and Grosmann, Carla and Camacho, Ana and Mohassel, Payam and Leach, Meganne E and Foley, A Reghan and Bharucha-Goebel, Diana and Collins, James and Connolly, Anne M and Gilbreath, Heather R and Iannaccone, Susan T and Castro, Diana and Cummings, Beryl B and Webster, Richard I and Lazaro, Le{\"\i}la and Vissing, John and Coppens, Sandra and Deconinck, Nicolas and Luk, Ho-Ming and Thomas, Neil H and Foulds, Nicola C and Illingworth, Marjorie A and Ellard, Sian and McLean, Catriona A and Phadke, Rahul and Ravenscroft, Gianina and Witting, Nanna and Hackman, Peter and Richard, Isabelle and Cooper, Sandra T and Kamsteeg, Erik-Jan and Hoffman, Eric P and Bushby, Kate and Straub, Volker and Udd, Bjarne and Ferreiro, Ana and North, Kathryn N and Clarke, Nigel F and Lek, Monkol and Beggs, Alan H and B{\"o}nnemann, Carsten G and MacArthur, Daniel G and Granzier, Henk and Davis, Mark R and Laing, Nigel G} } @article {454, title = {P4HA1 mutations cause a unique congenital disorder of connective tissue involving tendon, bone, muscle and the eye.}, journal = {Hum Mol Genet}, volume = {26}, year = {2017}, month = {2017 06 15}, pages = {2207-2217}, abstract = {

Collagen prolyl 4-hydroxylases (C-P4Hs) play a central role in the formation and stabilization of the triple helical domain of collagens. P4HA1 encodes the catalytic α(I) subunit of the main C-P4H isoenzyme (C-P4H-I). We now report human bi-allelic P4HA1 mutations in a family with a congenital-onset disorder of connective tissue, manifesting as early-onset joint hypermobility, joint contractures, muscle weakness and bone dysplasia as well as high myopia, with evidence of clinical improvement of motor function over time in the surviving patient. Similar to P4ha1 null mice, which die prenatally, the muscle tissue from P1 and P2 was found to have reduced collagen IV immunoreactivity at the muscle basement membrane. Patients were compound heterozygous for frameshift and splice site mutations leading to reduced, but not absent, P4HA1 protein level and C-P4H activity in dermal fibroblasts compared to age-matched control samples. Differential scanning calorimetry revealed reduced thermal stability of collagen in patient-derived dermal fibroblasts versus age-matched control samples. Mutations affecting the family of C-P4Hs, and in particular C-P4H-I, should be considered in patients presenting with congenital connective tissue/myopathy overlap disorders with joint hypermobility, contractures, mild skeletal dysplasia and high myopia.

}, keywords = {Animals, Basement Membrane, Bone and Bones, Child, Collagen Type IV, Connective Tissue, Humans, Male, Mice, Mice, Knockout, Muscles, Mutation, Osteochondrodysplasias, Procollagen-Proline Dioxygenase, Prolyl Hydroxylases, Tendons}, issn = {1460-2083}, doi = {10.1093/hmg/ddx110}, author = {Zou, Yaqun and Donkervoort, Sandra and Salo, Antti M and Foley, A Reghan and Barnes, Aileen M and Hu, Ying and Makareeva, Elena and Leach, Meganne E and Mohassel, Payam and Dastgir, Jahannaz and Deardorff, Matthew A and Cohn, Ronald D and DiNonno, Wendy O and Malfait, Fransiska and Lek, Monkol and Leikin, Sergey and Marini, Joan C and Myllyharju, Johanna and B{\"o}nnemann, Carsten G} }