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Copyright of China Journal of Oral & Maxillofacial Surgery is the property of Shanghai Jiao Tong University, College of Stomatology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Journal of Oral & Maxillofacial Surgery is the property of Shanghai Jiao Tong University, College of Stomatology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: The ANO5 gene encodes for anoctamin-5, a chloride channel involved in muscle cell membrane repair. Recessive mutations in ANO5 are associated with muscular diseases termed anoctaminopathies, which are characterized by proximal or distal weakness, or isolated hyperCKemia. We present the largest series of patients with asymptomatic/paucisymptomatic anoctaminopathy reported so far, highlighting their clinical and radiological characteristics. Methods: Twenty subjects were recruited retrospectively from the Neuromuscular Disorders Units database of two national reference centers. All had a confirmed genetic diagnosis (mean age of diagnosis was 48 years) established between 2015 and 2019. Clinical and complementary data were evaluated through clinical records. Results: None of the patients complained about weakness or showed abnormal muscular balance. Among paucisymptomatic patients, the main complaints or findings were generalized myalgia, exercise intolerance and calf hypertrophy, occasionally associated with calf pain. All patients showed persistent hyperCKemia, ranging from mild-moderate to severe. Muscle biopsy revealed inflammatory changes in three cases. Muscle magnetic resonance imaging revealed typical signs (preferential involvement of adductor and gastrocnemius muscles) in all but one patient. In two cases, abnormal findings were detectable only in STIR sequences (not in T1). Three patients showed radiological progression despite remaining asymptomatic. Twelve different mutations in ANO5 were detected, of which seven are novel. Conclusions: Recessive mutations in ANO5 are a frequent cause of undiagnosed asymptomatic/paucisymptomatic hyperCKemia. Patients with an apparent indolent phenotype may show muscle involvement in complementary tests (muscle biopsy and imaging), which may progress over time. Awareness of anoctaminopathy as the cause of nonspecific muscular complaints or of isolated hyperCKemia is essential to correctly diagnose affected patients. [ABSTRACT FROM AUTHOR]

Recessive mutations in the anoctamin 5 ( ANO5) gene have been recently identified in families with limb girdle muscular dystrophy (LGMD2L) and distal non-dysferlin Miyoshi myopathy. Anoctamin 5 is supposed to be a putative calcium-activated chloride channel. We report five German patients (four index patients) with muscle dystrophy due to mutations in the ANO5 gene. Sequencing of the ANO5 exons 5, 13 and 20 was performed to screen for a common c.191dupA mutation and two other reported mutations (c.1295C>G and p.R758C). The whole coding region of the ANO5 gene was sequenced to identify new mutations. Phenotypically, three patients showed LGMD and one patient Miyoshi type distal myopathy. One sibling had asymptomatic hyperCKemia. The age at onset was 64, 38 and 40 years in patients with LGMD and 23 years in the patient with distal myopathy. The four symptomatic patients showed remarkable asymmetric muscle involvement. There was marked CK elevation (11 to 30 times). Electron microscopy showed multifocal gaps in the sarcolemmal membrane. All patients harboured the common c.191dupA mutation in at least one allele. Two patients with LGMD were homozygous and the third patient and his asymptomatic sister were compound heterozygous for the c.191dupA mutation and a novel p.T548I mutation. The patient with distal myopathy harboured the p.R758C mutation in the second allele. Mutations in the ANO5 gene seem to be a relatively common cause of muscular dystrophy in Germany. Cases with late onset or asymptomatic hyperCKemia can occur. Clinically, asymmetric manifestation is typical. [ABSTRACT FROM AUTHOR]