Becker muscular dystrophy with r(X) carrying an out-of-frame DMD deletion

Becker muscular dystrophy: case report, review of the literature, and analysis of differentially expressed hub genes

INTRODUCTION

Becker muscular dystrophy (BMD) is a genetic and progressive neuromuscular disease caused by mutations in the dystrophin gene with no available cure. A case report and comprehensive review of BMD cases aim to provide important clues for early diagnosis and implications for clinical practice. Genes and pathways identified from microarray data of muscle samples from patients with BMD help uncover the potential mechanism and provide novel therapeutic targets for dystrophin-deficient muscular dystrophies.

METHODS

We describe a BMD family with a 10-year-old boy as the proband and reviewed BMD cases from PubMed. Datasets from the Gene Expression Omnibus database were downloaded and integrated with the online software.

RESULTS

The systematic review revealed the clinical manifestations and mutation points of the dystrophin gene. Gene ontology analysis showed that extracellular matrix organization and extracellular structure organization with enrichment of upregulated genes coexist in three datasets. We present the first report of TUBA1A involvement in the development of BMD/Duchenne muscular dystrophy (DMD).

DISCUSSION

This study provides important implications for clinical practice, uncovering the potential mechanism of the progress of BMD/DMD, and provided new therapeutic targets.

Dual diagnoses in 152 patients with Turner syndrome: Knowledge of the second condition may lead to modification of treatment and/or surveillance

Turner syndrome is a sex chromosome abnormality in which a female has a single X chromosome or structurally deficient second sex chromosome. The phenotypic spectrum is broad, and atypical features prompt discussion of whether the known features of Turner syndrome should be further expanded. With the advent of clinical whole exome sequencing, there has been increased realization that some patients with genetic disorders carry a second genetic disorder, leading us to hypothesize that a "dual diagnosis" may be more common than suspected for Turner syndrome. We report five new patients with Turner syndrome and a co-occurring genetic disorder including one patient with Li-Fraumeni syndrome, Li-Fraumeni and Noonan syndrome, mosaic trisomy 8, pathogenic variant in RERE, and blepharophimosis-ptosis-epicanthanus inversus syndrome. We also undertook an extensive literature review of 147 reports of patients with Turner syndrome and a second genetic condition. A total of 47 patients (31%) had trisomy 21, followed by 36 patients (24%) had one of 11 X-linked disorders. Notably, 80% of the 147 reported patients with a dual diagnosis had mosaicism for Turner syndrome, approximately twice the frequency in the general Turner syndrome population. This article demonstrates the potential for co-occurring syndromes in patients with Turner syndrome, prompting us to recommend a search for an additional genetic disorder in Turner patients with unusual features. Knowledge of the second condition may lead to modification of treatment and/or surveillance. We anticipate that increased awareness and improved diagnostic technologies will lead to the identification of more cases of Turner syndrome with a co-occurring genetic syndrome.

Carrier woman of Duchenne muscular dystrophy mimicking inflammatory myositis

Carrier woman of Duchenne muscular dystrophy (DMD) can mimic the inflammatory myositis in presenting symptoms. Two diseases should be differentiated by the clinical history, muscle biopsy and genetic study. There are few reports in which both histochemical and genetic study showed the possible link of overlapping inflammatory pathophysiology with dystrophinopathy. We report a 40-yr-old woman who presented with subacute proximal muscle weakness and high serum level of creatine kinase. She had a history of Graves' disease and fluctuation of serum liver aminotransferase without definite cause. MRI, EMG and NCV were compatible with proximal muscle myopathy. Muscle biopsy on vastus lateralis showed suspicious perifascicular atrophy and infiltration of mono-macrophage lineage cells complicating the diagnosis. Dystrophin staining showed heterogeneous diverse findings from normal to interrupted mosaic pattern. Multiple ligation probe amplification and X chromosome inactivation test confirmed DMD gene deletion mutation in exon 44 and highly skewed X inactivation.