Table 1.

Comparisons of age onset and neuropathological features of FUS‐immunostaining in familial ALS cases with FUS/TLS mutations. Abbreviations: Nucl = nuclear; Cyto = cytoplasmic; MΦ = macrophage infiltration; N/A = not available.

	R521G (13)	R521H/R521C (28)	R521C (2)	R521C (26)	P525L†
Age of onset	39.6 ± 13.3	N/A	42.6 ± 15.4	40.7 ± 13.8	13
Immunohistochemistry (IHC)
FUS
– Spinal motor neurons	Nucl/Cyto (diffuse)	Cyto (inclusion)	N/A	Cyto (inclusion)	Cyto (inclusion)
– Cortical neurons	Nucl/Cyto (diffuse)	N/A	N/A	N/A	Cyto (inclusion)
Ubiquitin
– Spinal motor neurons	Nucl	Rare	Cyto	Cyto (inclusion)	Cyto (diffuse)
– Cortical neurons	Nucl	Rare	Cyto	N/A	Cyto (diffuse)
TDP‐43
– Spinal motor neurons	N/A	Absent	Nucl	N/A	Nucl
– Cortical neurons	N/A	Absent	Nucl	N/A	Nucl
Spinal cord white matter
pallor	+	+	+	+++	++

^† This study.