Novel de novo frameshift variant in the ASXL3 gene in a child with microcephaly and global developmental delay.

De novo sequence variants, including truncating and splicing variants, in the additional sex­combs like 3 gene (ASXL3) have been described as the cause of Bainbridge­Ropers syndrome (BRS). This pathology is characterized by delayed psychomotor development, severe intellectual disability, growth delay, hypotonia and facial dimorphism. The present study reports a case of a girl (born in 2013) with severe global developmental delay, central hypotonia, microcephaly and poor speech. The proband was examined using a multi­step molecular diagnostics algorithm, including karyotype and array­comparative genomic hybridization analysis, with negative results. Therefore, the proband and her unaffected parents were enrolled for a pilot study using targeted next­generation sequencing technology (NGS) with gene panel ClearSeq Inherited DiseaseXT and subsequent validation by Sanger sequencing. A novel de novo heterozygous frameshift variant in the ASXL3 gene (c.3006delT, p.R1004Efs*21), predicted to result in a premature termination codon, was identified. In conclusion, the present study demonstrated that targeted NGS using a suitable, gene­rich panel may provide a conclusive molecular genetics diagnosis in children with severe global developmental delays.

Mutation analysis of TRPS1 gene including core promoter, 5'UTR, and 3'UTR regulatory sequences with insight into their organization.

The TRPS1 protein is a potent regulator of proliferation, differentiation, and apoptosis. The TRPS1 gene aberrations are strongly associated with rare trichorhinophalangeal syndrome (TRPS) development. We have conducted MLPA analysis to capture deletion within the crucial 8q24.1 chromosomal region in combination with mutation analysis of TRPS1 gene including core promoter, 5'UTR, and 3'UTR sequences in nine TRPS patients. Low complexity or extent of untranslated regulatory sequences avoided them from analysis in previous studies. Amplicon based next generation sequencing used in our study bridge over these technical limitations. Finally, we have made extended in silico analysis of TRPS1 gene regulatory sequences organization. Single contiguous deletion and an intragenic deletion intervening several exons were detected. Mutation analysis revealed five TRPS1 gene aberrations (two structural rearrangements, two nonsense mutations, and one missense substitution) reaching the overall detection rate of 78%. Several polymorphic variants were detected within the analysed regulatory sequences but without proposed pathogenic effect. In silico analysis suggested alternative promoter usage and diverse expression effectivity for different TRPS1 transcripts. Haploinsufficiency of TRPS1 gene was responsible for most of the TRPS phenotype. Structure of TRPS1 gene regulatory sequences is indicative of generally low single allele expression and its tight control.

Seminal plasma homocysteine, folate and cobalamin in men with obstructive and non-obstructive azoospermia.

PURPOSE: The aim of this study was to analyze homocysteine, folate and cobalamin in men with normozoospermia, obstructive and non-obstructive azoospermia. METHODS: Analysis of plasma and seminal plasma homocysteine, folate and cobalamin in 72 azoospermic and 62 normozoospermic men. Evaluation of the azoospermic patient included testicular biopsy, endocrine, urological and ultrasound examination. RESULTS: Homocysteine (1.2 µmol/l) and cobalamin (322.05 pmol/l) concentrations (median values) in seminal plasma were significantly lower (p < 0.001) in men with azoospermia than in men with normozoospermia (2.5 µmol/l and 579.0 pmol/l). Folate and cobalamin concentrations were significantly higher in obstructive than in non-obstructive azoospermia. Significant correlations were determined between testis volume and seminal plasma homocysteine in azoospermic men. CONCLUSION: Lower concentrations of homocysteine and cobalamin (but not folate) were found in azoospermic seminal plasma than normozoospermic. Folate and cobalamin were higher in seminal plasma from obstructive azoospermia than in non-obstructive azoospermia patients.