Frequencies of the main clinical features in the two patient cohorts.

<p>Frequencies of the main clinical features in the two patient cohorts.</p

Transverse MR brain images.

<p>Transverse MR brain images (T2-weighted) of four affected Eurasier dogs at the level of the cerebellar peduncles (B) and medulla oblongata (A, C, D). The myelencephalon appears unremarkable. The fourth ventricle has a cyst-like appearance in the rostral sections (B) and is continuous with retrocerebellar cerebrospinal fluid accumulations in the more caudal sections (A, C, D). A: dog 6; B: dog 7; C: dog 9; D: dog 10.</p

Dorsal MR brain images.

<p>Dorsal MR brain images (T2-weighted) of the affected Eurasier dogs reveal a prominent midline defect with absent caudal portions of the cerebellar vermis (midline) and cerebellar hemispheres (lateral) in association with a large retrocerebellar fluid accumulation. A: dog 6; B: dog 7; C: dog 9; D: dog 10. Images A and D are located more ventrally than B and C.</p

Neuroimaging findings in Eurasier dogs with familial non-progressive ataxia and inferior cerebellar hypoplasia resembling a DWLM.

<p>MRI: magnetic resonance images; CT: computed tomographic images</p><p>Neuroimaging findings in Eurasier dogs with familial non-progressive ataxia and inferior cerebellar hypoplasia resembling a DWLM.</p

Midline caudal fossa ratio in Eurasier dogs with (1) and without (2) cerebellar hypoplasia.

<p>Boxplots demonstrate wide variations in midline caudal fossa ratio in Eurasier dogs with inferior cerebellar hypoplasia resembling DWLM (1: range 0.191–0.441; n = 9) compared to Eurasier dogs with unremarkable brain images (2: range 0.2645–0.3300; n = 10). Midline caudal fossa ratio was increased in three dogs with inferior cerebellar hypoplasia resembling DWLM (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0117670#pone.0117670.s007" target="_blank">S1 Table</a>).</p

Eurasier dog breed.

<p>Eurasier dog breed.</p

Pedigree.

<p>Pedigree of Eurasier dogs with familial non-progressive ataxia and cerebellar hypoplasia resembling a Dandy-Walker like malformation (DWLM). Female dog, ○; male dog, □; black, confirmed cases; the numbers refer to the dog numbers in Tables <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0117670#pone.0117670.t001" target="_blank">1</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0117670#pone.0117670.t002" target="_blank">2</a>; gray, suspected cases, based on clinical signs, not confirmed by imaging. All cases could be traced to a common female founder.</p

Midsagittal MR brain images.

<p>Midsagittal MR brain images (T2-weighted) of the affected Eurasier dogs. In all dogs, a uniform cerebellar malformation was identified, characterized by absence of the caudal portions of the cerebellar vermis and, to a lesser degree, the caudal aspects of the cerebellar hemispheres and large caudal (posterior) fossa fluid accumulations (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0117670#pone.0117670.s002" target="_blank">S2</a> –<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0117670#pone.0117670.s006" target="_blank">S6</a> Figs.). The fourth ventricle appeared enlarged on midsagittal views and continuous with large retrocerebellar fluid accumulations (large arrow). Tissue remnants in the rostrodorsal caudal fossa correspond to the rostral portions of the cerebellar vermis (small arrow). Note the cyst-like appearance of the fourth ventricle in D. A: dog 6; B: dog 7; C: dog 9; D: dog 10.</p