title: Cardiomyopathy in patients with POMT1-related congenital and limb-girdle muscular dystrophy.
abstract: Protein-o-mannosyl transferase 1 (POMT1) is a glycosyltransferase involved in α-dystroglycan (α-DG) glycosylation. Clinical phenotype in POMT1-mutated patients ranges from congenital muscular dystrophy (CMD) with structural brain abnormalities, to limb-girdle muscular dystrophy (LGMD) with microcephaly and mental retardation, to mild LGMD. No cardiac involvement has until now been reported in POMT1-mutated patients. We report three patients who harbored compound heterozygous POMT1 mutations and showed left ventricular (LV) dilation and/or decrease in myocardial contractile force: two had a LGMD phenotype with a normal or close-to-normal cognitive profile and one had CMD with mental retardation and normal brain MRI. Reduced or absent α-DG immunolabeling in muscle biopsies were identified in all three patients. Bioinformatic tools were used to study the potential effect of POMT1-detected mutations. All the detected POMT1 mutations were predicted in silico to interfere with protein folding and/or glycosyltransferase function. The report on the patients described here has widened the clinical spectrum associated with POMT1 mutations to include cardiomyopathy. The functional impact of known and novel POMT1 mutations was predicted with a bioinformatics approach, and results were compared with previous in vitro studies of protein-o-mannosylase function.
authors.affiliation: Department of Neurosciences, University of Padova, Padova, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Bello
authors.forename: Paola
authors.initials: P
authors.lastname: Melacini
authors.forename: Raffaele
authors.initials: R
authors.lastname: Pezzani
authors.forename: Adele
authors.initials: A
authors.lastname: D'Amico
authors.forename: Luisa
authors.initials: L
authors.lastname: Piva
authors.forename: Emanuela
authors.initials: E
authors.lastname: Leonardi
authors.forename: Annalaura
authors.initials: A
authors.lastname: Torella
authors.forename: Gianni
authors.initials: G
authors.lastname: Soraru
authors.forename: Arianna
authors.initials: A
authors.lastname: Palmieri
authors.forename: Gessica
authors.initials: G
authors.lastname: Smaniotto
authors.forename: Bruno F
authors.initials: BF
authors.lastname: Gavassini
authors.forename: Andrea
authors.initials: A
authors.lastname: Vianello
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Nigro
authors.forename: Enrico
authors.initials: E
authors.lastname: Bertini
authors.forename: Corrado
authors.initials: C
authors.lastname: Angelini
authors.forename: Silvio C E
authors.initials: SC
authors.lastname: Tosatto
authors.forename: Elena
authors.initials: E
authors.lastname: Pegoraro
mesh_terms: D000293:Adolescent; D000328:Adult; D000595:Amino Acid Sequence; D009202:Cardiomyopathies / Q000175:diagnosis / Q000235:genetics*; D049030:Dystroglycans / Q000172:deficiency; D006579:Heterozygote; D006801:Humans; D008607:Intellectual Disability / Q000175:diagnosis / Q000235:genetics; D008297:Male; D008364:Mannosyltransferases / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D009136:Muscular Dystrophies / Q000151:congenital / Q000175:diagnosis / Q000235:genetics*; D049288:Muscular Dystrophies, Limb-Girdle / Q000175:diagnosis / Q000235:genetics*; D009154:Mutation; D009200:Myocardial Contraction; D017510:Protein Folding; D013577:Syndrome
chemical_list: D049030:Dystroglycans; D008364:Mannosyltransferases; C082696:protein O-mannosyltransferase