FSHD1 Diagnosis in a Russian Population Using a qPCR-Based Approach.

Facioscapulohumeral dystrophy (FSHD) is an autosomal dominant myodystrophy. Approximately 95% of cases of FSHD are caused by partial deletion of the D4Z4 macrosatellite tandem repeats on chromosome 4q35. The existing FSHD1 diagnostic methods are laborious and not widely used. Here, we present a comprehensive analysis of the currently used diagnostic methods (Southern blotting and molecular combing) against a new qPCR-based approach for FSHD1 diagnosis. We observed 93% concordance between the results obtained by the new qPCR-based approach, reference Southern blotting and molecular combing methods. Applying the qPCR-based approach in the studied population, we observed a prevalence (64.9%) of the permissive alleles in the range of 3-6 D4Z4 units for a group of patients, while in a group of carriers, the permissive alleles were mostly (84.6%) present in the range of 6-9 D4Z4 units. No prevalence of disease penetrance depending on gender was observed. The results confirmed the earlier established inverse correlation between permissive allele size and disease severity, disease penetrance. The results suggest the applicability of the qPCR-based approach for FSHD1 diagnosis and its robustness in a basic molecular genetics laboratory. To our knowledge, this is the first study of FSHD1 permissive allele distribution in a Russian population.

Protein partners of KCTD proteins provide insights about their functional roles in cell differentiation and vertebrate development.

The KCTD family includes tetramerization (T1) domain containing proteins with diverse biological effects. We identified a novel member of the KCTD family, BTBD10. A comprehensive analysis of protein-protein interactions (PPIs) allowed us to put forth a number of testable hypotheses concerning the biological functions for individual KCTD proteins. In particular, we predict that KCTD20 participates in the AKT-mTOR-p70 S6k signaling cascade, KCTD5 plays a role in cytokinesis in a NEK6 and ch-TOG-dependent manner, KCTD10 regulates the RhoA/RhoB pathway. Developmental regulator KCTD15 represses AP-2α and contributes to energy homeostasis by suppressing early adipogenesis. TNFAIP1-like KCTD proteins may participate in post-replication DNA repair through PCNA ubiquitination. KCTD12 may suppress the proliferation of gastrointestinal cells through interference with GABAb signaling. KCTD9 deserves experimental attention as the only eukaryotic protein with a DNA-like pentapeptide repeat domain. The value of manual curation of PPIs and analysis of existing high-throughput data should not be underestimated.

Human RFP2 gene promoter: unique structure and unusual strength.

Human gene RFP2 is a candidate tumor suppressor located at 13q14.3 and deleted in multiple tumor types. To explore regulation of RFP2, we determined structure of the 5'-untranslated region of RFP2 gene and its promoter. RFP2 promoter area is TATA-less, highly enriched in G and C nucleotides, and contains multiple quadruplex forming GGGGA-repeats. Deletion analysis of 5'-flanking sequences demonstrated that repeat containing fragment possesses activity seven times exceeding that of the combined SV40 promoter/enhancer. Other unusual features of the RFP2 promoter include anomalously high electrostatic fields induced by sequence-dependent dipoles and very low nucleosome forming potential. A "minimized" version of the RFP2 promoter could be used for overexpression of the various transgenes in the mammalian cells.