{Reference Type}: Case Reports
{Title}: Recurrent pneumothorax in a case of tenascin-X deficient Ehlers-Danlos syndrome: Broadening the phenotypic spectrum.
{Author}: Santoreneos R;Vakulin C;Ellul M;Rawlings L;Hardy T;Poplawski N;
{Journal}: Am J Med Genet A
{Volume}: 188
{Issue}: 5
{Year}: 05 2022
{Factor}: 2.578
{DOI}: 10.1002/ajmg.a.62674
{Abstract}: The genomic region surrounding the Tenascin-XB gene (TNXB) is a complex and duplicated region, with several pseudogenes that predispose to high rates of homologous recombination. Classical-like Ehlers-Danlos syndrome (clEDS) is the result of tenascin-X deficiency due to biallelic loss of function variants in the TNXB gene. Here we present a patient with clEDS and spontaneous pneumothorax, a feature not previously reported to be associated with this condition. Two inherited pathogenic/likely pathogenic variants were identified; a previously reported deletion resulting in a TNXA/TNXB chimeric gene and a novel frameshift variant. The Tenascin-XB gene is well described in the literature to be associated with collagen metabolism, stabilization of the fibrillar-collagen matrix and is expressed abundantly in the extracellular matrix. We propose that tenascin-X deficiency is directly related to pneumothorax predisposition. This case expands the phenotypic spectrum of clEDS and highlights the challenges with molecular analysis and diagnosis.