Growth Hormone Treatment in Patients With Aggrecan (ACAN) Deficiency

This is a single center study. All participants will be recruited from the USA. The study
intends to recruit pre-pubertal children for inclusion in the 1 year growth hormone treatment
trial. The study also plans to collect the following detailed phenotypic data at the first
study visit: height, weight, musculoskeletal evaluation, photographs, radiographs (knees,
left hand), MRI of the knees. The participants will be required to return to Cincinnati
Childrens Hospital Medical Center (CCHMC) for 3 study visits over the 12 month period. At the
follow up visits participants will receive a routine physical/pubertal exam, joint exam, have
vitals sign checked, height/weight taken, and labs drawn. A funduscopic exam will be
performed to look for signs of intracranial pressure. Study participants are also required to
complete phone check ins at scheduled intervals, and a locally drawn blood sample to check
insulin-like growth factor (IGF1) levels approximately 3 months after treatment start date.
Concomitant medications, adverse events will be recorded and updated at all study visits and
phone check ins. Medication will be resupplied and shipped to the participant as needed at
every point of follow up contact.

The study will enroll interested and affected relatives of the participant in the joint
phenotyping protocol as well. These participants will come to CCHMC only one time to complete
the phenotyping procedures. This is not an outcome of the study but the information gathered
from the imaging will provide insight into the effects of ACAN mutation on the joint
cartilage.

Age and sex matched controls will be recruited from CCHMC department of Sports Medicine for
all individuals that undergo the knee MRI procedures. This is to establish normative data for
comparison.

Inclusion Criteria:

1. ACAN Deficiency - Patients must be heterozygous for a mutation in the ACAN gene. A
mutation will be defined as:

a. A heterozygous deletion of the entire gene or of >1 complete exons of the gene b.
Any truncating mutation including frameshift, nonsense, splice site mutations within 2
bases of the exon/intron boundary, and start loss variants c. Any missense mutation
which meets the following criteria: i. It is absent in the Exome Aggregation
Consortium Database (exac.broadinstitute.org) ii. It is predicted to be damaging by
BOTH Polyphen2 and Sorting Intolerant From Tolerant (SIFT) iii. It segregates with the
short stature phenotype in the family or is a de novo mutation d. In-frame insertions
or deletions of >1 amino acid e. In-frame insertions or deletions of 1 amino acid must
meet the same criteria as missense mutations. For the prediction programs, Alanine
will be substituted for the deleted amino acid.

f. NOTE - Retrospective data does not show any correlation between the type of
mutation and the severity of short stature. Therefore, all mutations meeting the above
criteria will be included as a single group.

2. Age - Greater than or equal to 3 years 0 days. There is no specific upper age limit,
but the onset of puberty will make the patient ineligible.

3. Pre-pubertal

1. Male subjects must have a testicular volume <4 cc as determined on physical
examination by a pediatric endocrinologist at the time of the screening visit

2. Female subjects must be Tanner 1 for breast development as determined on physical
examination by a pediatric endocrinologist at the time of the screening visit

4. Bone Age - The bone age as determined by the Greulich and Pyle method must be equal to
or greater than the chronological age. Bone ages will be determined at the screening
visit by a single centralized radiologist.

5. Insulin-like growth factor (IGF-I) level within normal range for age and sex.

6. Ability to provide informed consent before any trial-related activities

7. NOTE - There is no specific height standard deviation criteria for inclusion in this
study.

Exclusion Criteria:

1. Prior treatment with any of the following therapies:

A. Growth hormone B. Insulin-like Growth Factor (IGF-I) C. Gonadotropin releasing
hormone (GnRH) analog D. Aromatase Inhibitor E. Oxandrolone

2. History of any type of malignancy

3. Growth plate fusion - Defined as a bone age via the Greulich and Pyle method of 13
years in females and 15 years in males

4. Chronic medical condition known to affect growth including but not limited to:

A. Cystic fibrosis B. Diabetes C. Inflammatory Bowel Disease D. Celiac Disease E.
Asthma requiring a daily inhaled steroid dose > 400 micrograms of inhaled budesonide
per day or equivalent F. Taking daily oral glucocorticoids for any reason G. Note -
attention deficit hyperactivity disorder (ADHD) treated with a stimulant and treated
hypothyroidism with a normal thyroid stimulating hormone (TSH) will NOT exclude the
subject from participating in the trial.

5. (BMI) <5th percentile (CDC growth charts)

6. Any clinically significant abnormality on screening laboratory tests as determined by
the principal investigator.

7. Known or suspected allergy to trial medication, excipients, or related products.

8. Contraindications to study medications, worded specifically as stated in the product's
prescribing information.

9. The receipt of any investigational drug within 90 days prior to this trial.