Arterial Tortuosity Syndrome (ATS) is a rare autosomal recessive connective tissue disorder caused by pathogenic variants in SLC2A10, which encodes the facilitative glucose transporter GLUT10. Although its vascular features are well recognized, the molecular consequences of many truncating variants remain poorly understood. We report a patient with ATS carrying a homozygous nonsense variant, c.485G > A (p.Trp162Ter), identified by whole-exome sequencing. Quantitative real-time PCR assessed SLC2A10 expression, and integrated bioinformatic analyses (structural modeling, druggability prediction, transmembrane topology, molecular docking, and molecular dynamics) explored its structural impact. The patient presented with severe systemic arterial tortuosity, congenital cardiovascular anomalies, hernias, connective tissue abnormalities, and neurovascular involvement involving cerebral tortuosity and distal intracranial narrowing. Structural modeling revealed extensive truncation of GLUT10 and loss of multiple α-helical domains, with transmembrane helices reduced from twelve to five. Docking of nine known ligands showed weaker binding to the mutant, and Compound 892 bound most strongly to the wild type (−7.469 kcal/mol). Across 300 ns simulations, the mutant complex proved markedly less stable. qRT-PCR showed no significant transcript differences among patient, carriers, and controls. Our findings broaden the neurovascular spectrum of SLC2A10-related ATS and demonstrate that p.(Trp162Ter) severely disrupts GLUT10 architecture, topology, and ligand binding.
Serdar Bozlak, Cüneyd Yavaş, Evrim Yalcin et al.· International Journal of Mol...· 0 citations
Background: Biallelic loss-of-function variants in LAMC3, encoding laminin gamma-3, cause occipital cortical malformation (OMIM#614115). White matter disease and intracranial neoplasia have not been reported in this spectrum. We report a novel homozygous LAMC3 frameshift variant, expanding its phenotypic and molecular spectrum. Methods: Two adolescent siblings from a consanguineous Turkish family underwent whole-exome sequencing, with segregation confirmed by NGS/IGV and classification per ACMG/AMP criteria. In silico analyses included multiple sequence alignment, AlphaFold modeling of wild-type and mutant proteins, and docking against nidogen-1 (NID1). Results: Both siblings had a novel homozygous LAMC3 variant frameshift variant (NM_006059.4: c.1852_1882del; p.(Pro618Serfs*5)), classified as pathogenic (PVS1, PM2, PP3, PP1) with full cosegregation. Proband II.III, a 17-year-old female, developed postoperative epilepsy after resection of a tectal low-grade glioneuronal tumor harboring a somatic KRAS (NM_004985.3) p.(Gln61Lys) variant (VAF 42.9%), with periventricular white matter gliosis. Proband II.IV, a 15-year-old male, presented with confluent leukoencephalopathy, occipital pachygyria, parietal polymicrogyria, and subcortical band heterotopia, illustrating striking intrafamilial discordance. Conclusions: Docking analysis revealed that the cleavage removes the C-terminal nidogen-binding region, eliminates the predicted wild-type interface (residues 906–1029), and shifts the binding to an unnatural N-terminal surface. This finding is a hypothesis-generating result consistent with loss of function. This study expands the LAMC3 phenotype to include leukoencephalopathy and reports a co-occurring low-grade tectal glioneuronal tumor as a novel, single-case observation, supporting inclusion of LAMC3 in the differential diagnosis of pediatric leukoencephalopathies, particularly with consanguinity.
Serdar Bozlak, Cüneyd Yavaş, H. I. Yilmaz et al.· Life· 0 citations
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