Understanding Clinical Phenotypes and Collecting Biomarker Samples in C9ORF72 ALS

C9ORF72 repeat expansions were recently identified as a surprisingly common
cause of ALS (30% of familial and 5-10% of sporadic ALS). Data collected to
date suggest a toxic gain-of-function mechanism for the cause of neuronal loss,
either by creating RNA-foci that sequester important RNA binding proteins or by
translation of the repeat expansion into aggregation-prone dipeptides. This
fact makes antisense oligonucleotide knock-down of C9ORF72 repeat RNA an
attractive therapeutic strategy, which is already under development by several
groups. Given a recently completed Phase I trial using antisense oligos (ASOs)
targeted to SOD1, it is highly likely that a similar strategy will emerge for
C9ORF72 in the near future. However, our understanding of clinical
characteristics and effect of the hexanucleotide repeat expansion size for
C9ORF72 are not yet ready for such a clinical trial. Our collaborative effort
proposed here will generate these important phenotype/genotype correlations.

We need to understand the natural history of C9ORF72 related ALS in terms of
measures of rate of progression, and we need to understand how the size of the
hexanucleotide repeat expansion influences these disease parameters. Although
C9ORF72 is a relatively common genetic disorder, it only represents about 10%
of all ALS, and thus for a C9ORF72-focused clinical trial, defining an accurate
historical control population will be critical since there may not be enough
subjects for a placebo controlled trial. To be ready for upcoming therapeutic
trials, we need to start the detailed characterization of the C9ORF72 patients
immediately.

In order to define the natural history of C9ORF72 ALS and to understand how the
size of the repeats correlates with disease progression, the six sites will:

1. Enroll a total of 60 C9ORF72 ALS participants with known mutation at time of
enrollment
a. Each participant will have their C9 genetic mutation status confirmed by
either UMASS (via a Screening Visit blood sample sent overnight to their lab)
or a CLIA-approved testing laboratory report (FAX*ed to Dr. Timothy Miller for
review and approval).
b. (Optional procedure): For each enrolled C9ORF72 ALS subject, a Caregiver
will be invited to (1) enroll, (2) sign a consent form, and (3) complete a
series of ALS Caregiver Behavioral Questionnaires during the course of the
C9ORF72 ALS subject*s completion of his/her Screening Visit through Study
Visit7.
2. Determine C9ORF72 hexanucleotide repeat expansion size in all subjects
3. Define ALS disease course in C9ORF72 ALS subjects
4. Determine to what degree the disease course correlates with expansion size
5. Collect biomarker samples including blood and CSF.
With the successful completion of these studies we will have carefully defined
the genotype/phenotype correlations in C9ORF72 ALS subjects and thus conducted
the necessary ground work to launching a clinical trial in C9ORF72 positive
subjects.

The six sites participating in this study will have already defined and
identified C9ORF72 ALS positive patients / carriers who will be approached for
enrollment.
We will genotype a total of approximately 60 patients during the course of the
study (two years of recruitment followed by approximately two years of
follow-up). These subjects will be enrolled (screened) into the study and
then followed longitudinally.
(Optional): For each enrolled C9ORF72 ALS participant, a Caregiver will also be
invited to enroll, sign a consent form, and complete a series of ALS Caregiver
Behavioral Questionnaires during the C9ORF72 subject*s completion of: Screening
Visit * Study Visit 7.

Determine Expansion Size
In the 60 subjects we identify with C9ORF72 ALS expansions, we will define the
size of the repeat expansion in blood cells by Southern Blot. We will test
expansion size from the DNA collected at the 3rd and 7th Study Visits to
determine whether the expansion size changes over time.

Correlate Expansion Size with Phenotype
After we have collected 6 months* worth of phenotype data, we will begin to
correlate phenotype with expansion size.

C9ORF2 Subject:

Blood draw:
Likely: There may be minimal discomfort associated with the blood draw and
bleeding or bruising may occur. Some people become dizzy or feel faint.
Rare: There is a rare risk of infection at the site of the blood draw.

Lumbar Puncture (CSF Collection)
Likely/Common (Mild): Minor pain and/or pressure during the sampling
procedure; Local bruising at the sampling sites; Local swelling at the sampling
sites.
Less Likely/Less Common (Mild): All precautions will be taken to minimize this
risk. The CSF sampling procedure will be conducted by experienced physicians
specially trained to perform this technique. We are not aware that potential
side effects are related to the volume of CSF being removed in this study. The
risk of headache will be minimized by having the subject lie on their back for
30 minutes to one hour following the CSF collection procedure. Throughout the
CSF sampling procedure, and following the 1 hour rest period, a nurse or
physician will remain with the subject. If headaches occur during or following
CSF removal, they usually are mild and last 0-2 days. They can, however, be
quite severe and last up to a week if not treated with a local injection of
blood (blood patch) which usually stops the headache within hours. If the
subject has a severe headache after the study, we would recommend that s/he
receives a patch to resolve the headache as soon as possible. We will provide
for the patch at no charge. If the subject receives a patch or other medical
care from another institution, we will not pay for any charges or be able to
protect the subject*s confidentiality.
Rare: 1. Infection resulting from the sampling procedure. The risk of such an
infection is extremely low and is not greater than after blood is withdrawn
from your arm. 2. Acquired intraspinal epidermoid tumor: This complication is
extremely rare (and reports of epidermoid tumors in adults are rare) and
represents a condition in which skin fragments are introduced (which then can
grow) into the spinal canal at the time of the lumbar puncture. This
complication usually arises because of the use of a spinal needle without
stylette.
Our study uses spinal needles with stylette during the lumbar puncture
procedure.

Caregiver (of C9ORFf72 subject) completing ALS Caregiver Behavioral
Questionnaire:
Likely/Common/Mild: Questionnaire: The subject may find some of the questions
personal or uncomfortable to answer.

Participation in the study has no direct benefit for the subject.