Hypotrichosis-lymphedema-telangiectasia syndrome: Report of ileal atresia associated with a SOX18 de novo pathogenic variant and review of the phenotypic spectrum.

Hypotrichosis-lymphedema-telangiectasia syndrome (HLTS) is a rare condition caused by pathogenic variants in the SOX18 gene. SOX18 plays a key role in angio- and lymphangiogenesis due to its expression in venous endothelial cells from which the lymphatic system develops. It is also expressed in embryonic hair follicles, heart, and vascular smooth muscle cells. The main clinical symptoms of HLTS include sparse hair, alopecia totalis, lymphedema, most often affecting lower limbs, and telangiectatic lesions. Only 10 patients with a SOX18 pathogenic variant have been described that presented with additional features such as hydrocele, renal failure, arterial or pulmonary hypertension, aortic dilatation, and facial dysmorphism. Here, we summarize these phenotypic variations and report an additional HLTS patient, with a 14-nucleotide de novo duplication in SOX18 and congenital ileal atresia, a feature not previously associated with HLTS

Identification of a murine monoclonal antibody specific for an allotypic determinant on mouse CD3

A murine monoclonal antibody (mAb; 7D6) that was mitogenic for T cells was derived from 129/Sv animals immunized with a T helper clone from C57BL/6 origin. Fluoresceinated 7D6 labeled T cells from most common mouse strains but not from 129/Sv and LP/J animals, and this labelling was inhibited by the anti-CD3 epsilon mAb 145-2C11. The mitogenicity of 7D6 for T cells had a similar strain specificity. The antibody immunoprecipitated the T cell receptor (TcR) complex from a T cell hybridoma. After dissociation of this immunoprecipitate with detergents, the CD3 gamma and epsilon chains were retained by the 7D6 antibody. Immunoprecipitation data were also obtained with COS cells transfected with the CD3 gamma, delta or epsilon chains alone, in pairs or together. They confirmed that 7D6 bound the CD3 gamma-epsilon pair, suggesting that the antibody recognizes a conformational epitope formed by gamma-epsilon pairing, whereas 145-2C11 bound both gamma-epsilon and delta-epsilon pairs. These results, therefore, add to current information about TcR structure and subunit stoichiometry. We have demonstrated that the 7D6 mAb specifically binds to a CD3 dimer comprised of gamma and epsilon chains. We thus provide additional evidence that indicates that two CD3 epsilon chains are found within the receptor, one linked to CD3 gamma and the other to CD3 delta