Functional characterization of BRCA1 gene variants by mini-gene splicing assay

Mutational screening of the breast cancer susceptibility gene BRCA1 leads to the identification of numerous pathogenic variants such as frameshift and nonsense variants, as well as large genomic rearrangements. The screening moreover identifies a large number of variants, for example, missense, silent, and intron variants, which are classified as variants of unknown clinical significance owing to the lack of causal evidence. Variants of unknown clinical significance can potentially have an impact on splicing and therefore functional examinations are warranted to classify whether these variants are pathogenic or benign. Here we validate a mini-gene splicing assay by comparing the results of 24 variants with previously published data from RT-PCR analysis on RNA from blood samples/lymphoblastoid cell lines. The analysis showed an overall concordance of 100%. In addition, we investigated 13 BRCA1 variants of unknown clinical significance or putative variants affecting splicing by in silico analysis and mini-gene splicing assay. Both the in silico analysis and mini-gene splicing assay classified six BRCA1 variants as pathogenic (c.80+1G>A, c.132C>T (p.=), c.213−1G>A, c.670+1delG, c.4185+1G>A, and c.5075−1G>C), whereas six BRCA1 variants were classified as neutral (c.-19-22_-19-21dupAT, c.302−15C>G, c.547+14delG, c.4676−20A>G, c.4987−21G>T, and c.5278−14C>G) and one BRCA1 variant remained unclassified (c.670+16G>A). In conclusion, our study emphasizes that in silico analysis and mini-gene splicing assays are important for the classification of variants, especially if no RNA is available from the patient. This knowledge is crucial for proper genetic counseling of patients and their family members.     

Transcatheter Aortic Valve Implantation in the Elderly: Who to Refer?

In recent years, experience with transcatheter aortic valve implantation has led to improved outcomes in elderly patients with severe aortic stenosis (AS) who may not have previously been considered for intervention. These patients are often frail with significant comorbid conditions.     

Anti-N-Methyl-D-Aspartate Receptor Encephalitis with Favorable Outcome Despite Prolonged Status Epilepticus

Background

To describe a case of auto-immune encephalitis in an adolescent with favorable outcome despite prolonged status epilepticus.

Methods

A 17 year old Asian man without previous medical history developed alteration of consciousness and partial seizures. The diagnosis of anti-N-methyl-D-aspartate receptor encephalitis was confirmed by the detection of specific antibodies in both cerebrospinal fluid and serum.

Results

The clinical course was complicated by prolonged status epilepticus which was refractory to a large number of antiepileptic drugs, including barbiturate coma. Immunomodulatory therapy included steroids, plasma exchanges, and intravenous immunoglobulins. After 86 days of intensive therapy, the patient regained consciousness progressively. Brain magnetic resonance imaging never demonstrated any lesion. Extensive search for a tumor was negative. At 12 month follow-up, the patient had made an excellent recovery.

Conclusion

Auto-immune encephalitis is likely underdiagnosed in adolescents. In their most severe presentation, seizures may be resistant to a large number of anti-epileptic drugs, and the clinical improvement seems to be mainly because of the immunomodulatory therapy. Relapse is possible, as well as the delayed development of a teratoma or other tumor.