title: Diaphragmatic dysfunction in Collagen VI myopathies.
abstract: Collagen VI-related myopathies are hereditary disorders causing progressive restrictive respiratory insufficiency. Specific diaphragm involvement has been suggested by a drop in supine volumes. This pilot study aimed at characterizing the respiratory muscle phenotype in patients with COL6A1-3 genes mutations. Lung function, blood gases, muscle strength and respiratory mechanics were measured in 7 patients between 2002 and 2012. Patients were classified as Early-Severe (n = 3), Moderate-Progressive (n = 2) and Mild (n = 2) according to clinical disease presentation. Seven patients (aged 6-28) were evaluated. Forced vital capacity distinguished the Mild group (>60% predicted) from the two other groups (<50% predicted). This distinction was also possible using the motor function measure scale. Diaphragmatic dysfunction at rest was observed in all the Early-Severe and Moderate-Progressive patients. During a voluntary sniff maneuver diaphragmatic dysfunction was observed in all patients, as assessed by a negative gastric pressure. All patients had diaphragmatic fatigue assessed by a tension-time index over the threshold of 0.15. Diaphragmatic dysfunction during a maximal voluntary maneuver and diaphragmatic fatigue are constant features in Collagen VI myopathies. These observations can assist the diagnosis and should be taken in account for the clinical management, with the early detection of sleep-disordered breathing.
authors: Service de Pédiatrie, Centre de Référence Maladies Neuromusculaires (GNMH), AP-HP, Hôpital Raymond Poincaré, Garches, France; Université Versailles UVSQ, France; INSERM, UMRS_974, Paris, France.
authors: S
authors: S
authors: Quijano-Roy
authors: S2A Santé, Ivry-sur-Seine, France; Service de Pneumologie Pédiatrique, AP-HP, Hôpital Armand Trousseau, Paris, France.
authors: S
authors: S
authors: Khirani
authors: Clinique Pediatrique, Institut G. Gaslini, Gênes, Italy.
authors: M
authors: M
authors: Colella
authors: ADEP ASSISTANCE, Suresnes, France; Service de Pneumologie Pédiatrique, AP-HP, Hôpital Armand Trousseau, Paris, France.
authors: A
authors: A
authors: Ramirez
authors: Service de Pneumologie Pédiatrique, AP-HP, Hôpital Armand Trousseau, Paris, France.
authors: S
authors: S
authors: Aloui
authors: Service de Pédiatrie, Centre de Référence Maladies Neuromusculaires (GNMH), AP-HP, Hôpital Raymond Poincaré, Garches, France; Université Versailles UVSQ, France.
authors: S
authors: S
authors: Wehbi
authors: UF Cardiogénétique et Myogénétique, Service de Biochimie Métabolique, AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Paris, France.
authors: A
authors: A
authors: de Becdelievre
authors: Service de Radiologie, Pole Neuromoteur, AP-HP, Hôpital Raymond Poincaré, Garches, France; Université Versailles UVSQ, France.
authors: R Y
authors: RY
authors: Carlier
authors: UPMC Univ., Um76, Paris, 06, France; INSERM, UMRS_974, Paris, France; CNRS, UMR7215, France; Institut de Myologie, FR-75013 Paris, France.
authors: V
authors: V
authors: Allamand
authors: UF Cardiogénétique et Myogénétique, Service de Biochimie Métabolique, AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Paris, France.
authors: P
authors: P
authors: Richard
authors: Service de Pédiatrie, Centre de Référence Maladies Neuromusculaires (GNMH), AP-HP, Hôpital Raymond Poincaré, Garches, France; Université Versailles UVSQ, France.
authors: V
authors: V
authors: Azzi
authors: Service de Pédiatrie, Centre de Référence Maladies Neuromusculaires (GNMH), AP-HP, Hôpital Raymond Poincaré, Garches, France; Université Versailles UVSQ, France.
authors: B
authors: B
authors: Estournet
authors: Service de Pneumologie Pédiatrique, AP-HP, Hôpital Armand Trousseau, Paris, France; INSERM U955, Créteil, France. Electronic address: brigitte.fauroux@nck.aphp.fr.
authors: B
authors: B
authors: Fauroux
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D024142:Collagen Type VI / Q000235:genetics / Q000378:metabolism; D003937:Diagnosis, Differential; D003964:Diaphragm / Q000503:physiopathology*; D005260:Female; D060005:Genotyping Techniques; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009043:Motor Activity / Q000502:physiology; D053580:Muscle Strength / Q000235:genetics / Q000502:physiology; D009135:Muscular Diseases / Q000175:diagnosis / Q000235:genetics / Q000503:physiopathology*; D010641:Phenotype; D012146:Rest / Q000502:physiology; D012720:Severity of Illness Index; D014797:Vital Capacity; D055815:Young Adult
chemical_list: C553839:Col6a1 protein, human; D024142:Collagen Type VI
keywords: Bethlem myopathy; COLVI-related myopathy; Diaphragm; Motor function measure scale; Respiratory function; Ullrich congenital muscular dystrophy; Whole body muscle magnetic resonance imaging