Novel TINF2 gene mutation in dyskeratosis congenita with extremely short telomeres: A case report

BACKGROUND

Dyskeratosis congenita is a rare disease characterized by bone marrow failure and a clinical triad of oral leukoplakia, nail dystrophy, and abnormal skin pigmentation. The genetics of dyskeratosis congenita include mutations in genes involved in telomere maintenance, including TINF2.

CASE SUMMARY

Here, we report a female patient who presented thrombocytopenia, anemia, reticulate hyperpigmentation, dystrophy in fingernails and toenails, and leukoplakia on the tongue. A histopathological study of the skin showed dyskeratocytes; however, a bone marrow biopsy revealed normal cell morphology. The patient was diagnosed with dyskeratosis congenita, but her family history did not reveal significant antecedents. Whole-exome sequencing showed a novel heterozygous punctual mutation in exon 6 from the TINF2 gene, namely, NM_001099274.1:c.854delp.(Val285Alafs*32). An analysis of telomere length showed short telomeres relative to the patient’s age.

CONCLUSION

The disease in this patient was caused by a germline novel mutation of TINF2 in one of her parents.

Underexpression of circulating miR-145-5p and miR-133a-3p are associated with breast cancer and immunohistochemical markers

Background

MicroRNAs (miRNAs) are involved in the regulation of genes with important roles in cancer. Therefore, they represent interesting targets as biomarkers for early detection, follow-up, and prognosis of the disease.

Context

In early stages of breast cancer, differences in the expression of miR-148b-3p, miR-145-5p and miR-133a-3p have been reported.

Aims

To compare the expression of miR-148b-3p, miR-145-5p and miR-133a-3p in serum samples from female patients with and without breast cancer.

Setting and Design

Case control study.

Materials and Methods

We quantified the expression by real-time polymerase chain reaction of miR-148b-3p, miR-145-5p, and miR-133a-3p in serum samples from 27 breast cancer (BC) and 17 benign breast tumor patients.

Statistical Analysis Used

Comparison between groups with categorical variables was made using the Pearson's Chi-square test. Comparative analysis for continuous variables between two groups was performed using the Student's t-test. One-way analysis of variance (ANOVA) was used for multigroup comparison, followed by Tukey HSD analysis.

Results

The use of contraceptives and a high number of births were identified as risk factors for BC. We observed that miR-145-5p expresses in low levels in BC and positively diagnosed Her2 patients. In addition, BC patients with either ductal carcinoma or positive molecular diagnosis for estrogen receptor, progesterone receptor, luminal A, or Her2 negative, presented a decreased expression of miR-133a-3p.

Conclusions

We observed an existing association between the molecular characteristics of BC and levels of circulating miR-133a-3p and miR-145-5p, proving the potential role of miRNAs as biomarkers for BC.