Table 3.

Summary of inheritance observations among affected individuals in 43 kindreds with probands harbouring the non-coding GGGGCC hexanucleotide repeat expansion in C9ORF72

Inheritance observation	n (%)
Kindreds with apparent autosomal dominant pattern of inheritance	36 (84)
Only dementia or behavioural variant FTD present in same kindred	12 (33)
Only ALS phenotype present in same kindred	3 (8)
FTD and ALS phenotype present in same kindred	21 (58)
Apparent sporadic cases with no known family history of neurodegenerative disease	7 (16)
Apparent kindreds with incomplete penetrance	2 (5)
Apparent younger age of onset (>10 years) from one generation to the next	11 (26)