A Multi-center, Longitudinal, Observational Study of Children With Achondroplasia

Inclusion Criteria: 1. Legally authorized representative is willing and able to provide written, signed informed consent (with a written assent from the child when appropriate per local requirements) 2. Willing and able to comply with study protocol per investigator judgement 3. Clinical diagnosis of achondroplasia (confirmed by the investigator) 4. Age between 0 to 8 years old at enrollment 5. Able to stand without assistance (if the child is 24 months or older) Exclusion Criteria: 1. Have received chronic treatment (\> 3 months) of human growth hormone (hGH) or other medicinal products intended to affect stature or body proportionality at any time 2. Have received any dose of medicinal products intended to affect stature or body proportionality within the previous 6 months of screening 3. Have received any investigational medicinal product or device intended to affect stature or body proportionality at any time 4. History or presence of injury or disease of the growth plate(s), other than ACH, that affects growth potential of long bones 5. History of any bone-related surgery that affects growth potential of long bones, such as orthopedic reconstructive surgery and osteotomy (foramen magnum decompression, and laminectomy with full recovery are allowed with minimum of 6 months of bone healing. Limb-lengthening with full recovery is allowed with a minimum of 12 months of bone healing.) 6. Have forms of skeletal dysplasias other than achondroplasia or medical conditions that result in short stature or abnormal bone growth \[such as severe achondroplasia with developmental delay and acanthosis nigricans (SADDAN), hypochondroplasia, growth hormone deficiency, Turner syndrome, pseudoachondroplasia. uncontrolled hypothyroidism, uncontrolled diabetes mellitus, autoimmune disease requiring corticosteroid therapy, inflammatory bowel disease, and chronic renal insufficiency\] 7. History or presence of malignant disease, other than basal cell epithelioma/carcinoma or completely resected squamous skin cancer with no recurrence for 12 months per medical records