BACKGROUND: Pathogenic variants in the TPM3 gene, encoding slow skeletal muscle α-tropomyosin account for less than 5% of nemaline myopathy cases. Dominantly inherited or de novo missense variants in TPM3 are more common than recessive loss-of-function variants. The recessive variants reported to date seem to affect either the 5\' or the 3\' end of the skeletal muscle-specific TPM3 transcript.
OBJECTIVE: The aim of the study was to identify the disease-causing gene and variants in a Finnish patient with an unusual form of nemaline myopathy.
METHODS: The genetic analyses included Sanger sequencing, whole-exome sequencing, targeted array-CGH, and linked-read whole genome sequencing. RNA sequencing was done on total RNA extracted from cultured myoblasts and myotubes of the patient and controls. TPM3 protein expression was assessed by Western blot analysis. The diagnostic muscle biopsy was analyzed by routine histopathological methods.
RESULTS: The patient had poor head control and failure to thrive, but no hypomimia, and his upper limbs were clearly weaker than his lower limbs, features which in combination with the histopathology suggested TPM3-caused nemaline myopathy. Muscle histopathology showed increased fiber size variation and numerous nemaline bodies predominantly in small type 1 fibers. The patient was found to be compound heterozygous for two splice-site variants in intron 1a of TPM3: NM_152263.4:c.117+2_5delTAGG, deleting the donor splice site of intron 1a, and NM_152263.4:c.117 + 164 C>T, which activates an acceptor splice site preceding a non-coding exon in intron 1a. RNA sequencing revealed inclusion of intron 1a and the non-coding exon in the transcripts, resulting in early premature stop codons. Western blot using patient myoblasts revealed markedly reduced levels of the TPM3 protein.
CONCLUSIONS: Novel biallelic splice-site variants were shown to markedly reduce TPM3 protein expression. The effects of the variants on splicing were readily revealed by RNA sequencing, demonstrating the power of the method.

BACKGROUND: We report a patient with a novel c.737 C > T variant (p.Ser246Leu) of the TPM3 gene presenting with adult-onset distal myopathy.
METHODS: A 35-year-old Chinese male patient presented with a history of progressive finger weakness. Physical examination revealed differential finger extension weakness, together with predominant finger abduction, elbow flexion, ankle dorsiflexion and toe extension weakness. Muscle MRI showed disproportionate fatty infiltration of the glutei, sartorius and extensor digitorum longus muscles without significant wasting. Muscle biopsy and ultrastructural examination showed a non-specific myopathic pattern without nemaline or cap inclusions. Genetic sequencing revealed a novel heterozygous p.Ser246Leu variant (c.737C>T) of the TPM3 gene which is predicted to be pathogenic. This variant is located in the area of the TPM3 gene where the protein product interacts with actin at position Asp25 of actin. Mutations of TPM3 in these loci have been shown to alter the sensitivity of thin filaments to the influx of calcium ions.
CONCLUSIONS: This report further expands the phenotypic spectrum of myopathies associated with TPM3 mutations, as mutations in TPM3 had not previously been reported with adult-onset distal myopathy. We also discuss the interpretation of variants of unknown significance in patients with TPM3 mutations and summarise the typical muscle MRI findings of patients with TPM3 mutations.

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The efficacy of entrectinib, a potent inhibitor of tropomyosin receptor kinases, c-ros oncogene 1, and anaplastic lymphoma kinase has been demonstrated in neurotrophic receptor tyrosine kinase fusion-positive pediatric and adult solid tumors. However, real-world data on entrectinib therapy for salivary gland malignancies are limited.
We describe a multicenter case series of four consecutive patients with ETV6-NTRK3 fusion-positive metastatic salivary secretory carcinoma (SSC) treated with entrectinib.
All patients had a prior history of systemic therapy with cytotoxic chemotherapy or immune checkpoint inhibitors. All patients achieved durable radiographic complete response. Adverse events included weight gain, dizziness, increase in creatine kinase level, and withdrawal pain, but were manageable by the interruption and dose reduction of entrectinib.
Durable complete response was achieved with entrectinib in patients with ETV6-NTRK3 fusion-positive metastatic SSC. The clinical benefit of entrectinib supports the importance of routine screening for NTRK gene fusion in patients with SSC.

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BACKGROUND: Dilated cardiomyopathy (DCM) is a cardiovascular disorder characterized by consecutive ventricular dilation and contractile dysfunction, often leading to congestive heart failure. DCM type 1Y (DCM1Y) is caused by a mutation in the TPM1 (tropomyosin 1) gene. To date, about thirty TPM1 gene mutations have been reported to be related to DCM1Y. However, mutational screening of the TPM1 gene is still far from being complete. Identification of TPM1 mutation is particularly important in the diagnosis of DCM1Y and will give more insights into the molecular pathogenesis of DCM1Y.
METHODS: A Chinese Han family with DCM phenotypes was examined.
METHODS: A novel missense mutation, c.340G > C in exon 3 of the TPM1 gene, was identified.
METHODS: Next-generation sequencing (NGS) of DNA samples was performed to detect the gene mutation in the proband, which was confirmed by Sanger sequencing.
RESULTS: This novel heterozygous mutation results in the substitution of glutamic acid with glutamine (p.E114Q). Based on this finding and clinical manifestations, a final diagnosis of DCM1Y was made.
CONCLUSIONS: We present evidence that p.E114Q mutation represents a novel TPM1 mutation in a Chinese Han family with DCM. Our data expand the mutation spectrum of the TPM1 gene and may facilitate the clinical diagnosis of DCM1Y.

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Tropomyosin 1 (TPM1) is a protein that constitutes the sarcomere filaments and is encoded by the TPM1 gene. The aim of the present study is to investigate the correlation between the 3\' untranslated region (3\'UTR) single nucleotide polymorphisms (SNPs) of the TPM1 gene and dilated cardiomyopathy (DCM).A total of 245 patients with DCM and 245 healthy controls were recruited with 5 ml of venous blood. Genomic DNA was extracted to analyze the TPM1 gene rs12148828, rs11558748, rs707602, rs6738, rs7178040 loci genotypes, and the plasma miR-21 level was analyzed by reverse transcription-PCR (RT-PCR).The risk of DCM development in the rs6738 locus G allele carriers were 1.69 times more than A allele carriers (95% CI: 1.22-2.33, P = .001). Age and gender had no effect on the association of TPM1 gene SNPs with DCM risk (P > .05). The plasma miR-21 level of TPM1 gene rs6738 locus AA carriers was significantly higher than that of the AG and GG genotypes (P < .001).The SNPs of TPM1 gene rs6738 locus is associated with the risk of DCM, which may be related to the abnormal increase of miR-21 level in DCM patients, but further research is needed to prove the causal relationship between miR-21 level and DCM risk.

BACKGROUND: Translocation-associated renal cell carcinoma involving ALK (ALK-tRCC) is a rare subtype of adult renal cell carcinoma (RCC) reported in recent years. It was recognized as a group of emerging /provisional RCC in the latest World Health Organization\'s classification (2016).
METHODS: A new Chinese case of ALK-tRCC was reported. The patient was a 58-year-old man with a tumor in kidney. The tumor was composed of sheets of large cells with abundant eosinophilic cytoplasm and indistinct cell borders but conspicuous intracytoplasmic vacuoles. The nuclei were enlarged with a nucleolar of grade 4. Immunohistochemically, tumor cells were diffusely positive for PAX8, keratin (AE1/AE3), epithelial membrane antigen (EMA) and CK7. Fluorescent in situ hybridization (FISH) showed a rearrangement of ALK in tumor cells.
CONCLUSIONS: ALK-tRCC is a rare subtype of adult RCC. Its diagnosis is very difficult because the histological spectrum is very wide. We suggested that RCCs should be screened for ALK expression by immunohistochemistry (IHC) for the patient might benefit from ALK inhibitors therapy.