Observational study looking at the burden of illness in achondroplasia subjects aged 5-70. The study will include a 5 year review of historical clinical data as well as a single point collection of questionnaire data to look at the impact on the following in individuals with achondroplasia versus a normative population:

• Quality of life
• Clinical burden
• Healthcare resource use
• Socio-economic burden
• Psychosocial burden

Up to 300 subjects will be included in sites in Germany, Spain, Italy, Sweden, Austria and Denmark

This is a multinational, epidemiological, observational, retrospective, cross-sectional study of individuals with achondroplasia (subjects). This study will be conducted at up to approximately 20 sites in European countries.

Subjects will be invited to enroll via 3 routes:

1. During routine hospital visits
2. From subject lists of those previously treated but no longer followed at the study site.
3. Through collaboration of the Investigator with achondroplasia patient organizations, other achondroplasia-related organizations, other healthcare professionals in their country and achondroplasia-related social media sites. A recruitment flyer will be provided to these organizations, healthcare professionals and social media sites and will to be distributed to potential subjects.

Data will be collected over a minimum of the five years prior to the date of enrolment. Clinical and healthcare resource use data will be collected from medical records. For each subject enrolled, data from medical records will be collected and entered onto an electronic case report form (eCRF) at each site. Data collection from medical records will be supplemented by records provided by the subject and, if necessary, confirmed by the family doctor.

Data about QoL, psychosocial burden, socioeconomic burden and healthcare resource use will be collected via a booklet of validated and structured questionnaires.

Characteristics of subjects with achondroplasia (QoL scores, healthcare resource use, educational level, family status, employment status) will be compared with those of the general population, where available.

As this is an observational study, participation will not affect the subject/Investigator relationship, nor influence Investigator's treatment, therapeutic or other management of the subject.

Inclusion Criteria:

1. Individuals with a documented diagnosis of achondroplasia based on:

   1. Genetic confirmation of achondroplasia and/or
   2. Clinical diagnosis of achondroplasia (clinical examination or radiological assessment)

2. ≥ five years of age at the time of enrolment

3. Has the cognitive and linguistic capacities necessary to complete questionnaires in the language of his/her country (and/or parents/legally acceptable representatives, as applicable)

4. Agrees to participate in the study and has read, understood, completed and signed:

   1. Informed Consent Form (ICF) - for adult subjects
   2. Informed Assent Form (IAF) - for minor subjects, accompanied by a parental ICF completed by their parents/legally acceptable representatives. The age at which the minor subjects sign the IAF will be subject to local requirements.

5. Has medical records available for at least the five years prior to the date of enrolment.

Exclusion Criteria:

1. Currently participating, or participated within the last six months, in

   1. a clinical trial of a medicinal product or medical device or,
   2. other non-clinical, low interventional studies

2. Currently participating or participated in any BioMarin study at any time.

Individuals with a diagnosis of Achondroplasia aged 5 years or older in Sweden, Germany, Spain, Italy, Austria and Denmark.

August 2020