Frequency and phenotype of patients carrying TPM2 and TPM3 gene mutations in a cohort of 94 patients with congenital myopathy

Gulsenay Citirak, Nanna Witting, Morten Duno, Ulla Werlauff, Helle Petri, John Vissing

14 Citations (Scopus)

Abstract

Congenital myopathies are difficult to classify correctly through molecular testing due to the size and heterogeneity of the genes involved. Therefore, the prevalence of the various genetic causes of congenital myopathies is largely unknown. In our cohort of 94 patients with congenital myopathy, two related female patients and two sporadic, male patients were found to carry mutations in the tropomyosin 2 (TPM2) and tropomyosin 3 (TPM3) genes, respectively. This indicates a low (4.3%) frequency of TPM2 and TPM3 mutations as a cause of congenital myopathy. Compared to previously described patients carrying the same mutations as found in our study (c.503G>A, and c.502C>T in TPM3, and c.415_417delGAG in TPM2), clinical presentation and muscle morphological findings differed in our patients. Differences included variation in distribution of muscle weakness, presence of scoliosis and ptosis, physical performance and joint contractures. The variation in clinical profiles emphasizes the phenotypic heterogeneity. However, common features were also present, such as onset of symptoms in infancy or childhood, musculoskeletal deformities and normal or low plasma levels of creatine kinase. One patient had nemaline myopathy and fiber size disproportion, while three patients had congenital fiber type disproportion (CFTD) on muscle biopsies. TPM2-related CFTD has only been described in two cases, indicating that mutations in TPM2 are rare causes of CFTD.
Original languageEnglish
JournalNeuromuscular disorders : NMD
Volume24
Issue number4
Pages (from-to)325-30
ISSN0960-8966
DOIs
Publication statusPublished - 3 Jan 2014

Fingerprint

Dive into the research topics of 'Frequency and phenotype of patients carrying TPM2 and TPM3 gene mutations in a cohort of 94 patients with congenital myopathy'. Together they form a unique fingerprint.

Cite this