Figure 1.

Mutation screening of FOXP1 in verbal dyspraxia probands. (a) Genomic organisation of FOXP1. FOXP1 is located on chromosome 3p14.1 and consists of 16 coding exons spanning 586 kb. Exons are represented by filled bars whose width is proportional to the length of the exon. Numbering scheme is based on alignment with the published mouse Foxp1 structure.²⁰ Initiation codon is indicated by ‘atg' and stop codon by ‘tga'. The Zinc-Finger domain spans exons 7 and 8, the Leucine-Zipper domain spans exons 8 and 9 and the forkhead-box motif is encoded by exons 10–13. Locations of base changes summarised in Table 1 are indicated on figure by bars, with base change and frequency in probands. (b) Direct sequencing confirmed the presence of base changes in probands displaying aberrant DHPLC elution patterns (see also Table 1). The exon 5 polymorphism is shown for the proband and HRC samples that carried the C-to-G transversion, aligned with a proband that did not carry the change for comparison.