Table 3.

Frequency of Indels in C9orf72 Alleles in the Neurodegenerative Disease Cohort at University of Pennsylvania

C9orf72 allele	Total alleles, n	Alleles with indel, n	Allele frequency, %	Odds ratio	95% CI	P value
Nonexpanded allele∗	4150	38	0.92
Expanded allele	142	39	27.46	40.9729	25.159–66.725	<0.0001

Indel, insertion/deletion.

^∗Data for nonexpanded alleles were obtained from Center for Neurodegenerative Disease Research cohort patients with a variety of neurodegenerative diseases and healthy controls tested with the Penn-C9 assay, which is sensitive for detection of indels on nonexpanded alleles.