Figure 1.

Location of missense and nonsense mutations in SLC9A6/NHE6 variants of patients with Christianson syndrome. A, schematic planar drawing of the predicted membrane topology of the longest splice-variant of mammalian NHE6 and location of the mutations (yellow circles). Two consensus N-linked glycosylation sites (¹²⁸NVT and ¹⁴⁵NVS) within extracellular loop 2 have been verified experimentally (data not shown) and are illustrated in the drawing. B, phylogenetic comparison of the primary sequence of segments containing the various mutations in NHE6. The affected residues are shaded in black.