An improved characterization of horse ( Equus caballus

Abstract Peripheral blood lymphocytes were cultured and treated for early- and late-BrdU incorporation to perform replicating G- and R-banding patterns, respectively. Slides were treated for GBG-, RBA- and RBG-banding techniques. Improved banded karyotypes at early- (350 bands) and pro-metaphase (500 bands) stage were performed and GBG- and RBA-banded prometaphase karyotypes were presented for the first time on this species. All chromosomes, including the small acrocentrics, show clear and distinguishable G- and R-banding patterns. Chromosome identification followed the latest chromosome standard nomenclature (ISCNH 1997). This study is also our contribution to further standard karyotype attempts at the prometaphase stage

Novel pathogenic SMAD2 variants in five families with arterial aneurysm and dissection: further delineation of the phenotype

BACKGROUND: Missense variants in SMAD2, encoding a key transcriptional regulator of transforming growth factor beta signalling, were recently reported to cause arterial aneurysmal disease. OBJECTIVES: The aims of the study were to identify the genetic disease cause in families with aortic/arterial aneurysmal disease and to further define SMAD2 genotype-phenotype correlations. METHODS AND RESULTS: Using gene panel sequencing, we identified a SMAD2 nonsense variant and four SMAD2 missense variants, all affecting highly conserved amino acids in the MH2 domain. The premature stop codon (c.612dup; p.(Asn205*)) was identified in a marfanoid patient with aortic root dilatation and in his affected father. A p.(Asn318Lys) missense variant was found in a Marfan syndrome (MFS)-like case who presented with aortic root aneurysm and in her affected daughter with marfanoid features and mild aortic dilatation. In a man clinically diagnosed with Loeys-Dietz syndrome (LDS) that presents with aortic root dilatation and marked tortuosity of the neck vessels, another missense variant, p.(Ser397Tyr), was identified. This variant was also found in his affected daughter with hypertelorism and arterial tortuosity, as well as his affected mother. The third missense variant, p.(Asn361Thr), was discovered in a man presenting with coronary artery dissection. Variant genotyping in three unaffected family members confirmed its absence. The last missense variant, p.(Ser467Leu), was identified in a man with significant cardiovascular and connective tissue involvement. CONCLUSION: Taken together, our data suggest that heterozygous loss-of-function SMAD2 variants can cause a wide spectrum of autosomal dominant aortic and arterial aneurysmal disease, combined with connective tissue findings reminiscent of MFS and LDS