The objective of this study is to develop office-based tools to quantify gait in young children with NF1 that reflect overall gross motor impairment and predict future gross motor difficulties.

In this prospective observational study of ambulatory children less than six years old with NF1, investigators will evaluate gait speed as the fastest time to walk 10 meters and interlimb coordination derived from artificial intelligence-based pose estimates from video. Investigators will conduct office-based gait assessments with video, clinical exams, and neurodevelopmental evaluations during routine medical visits at baseline, 12 months, and 24 months at one of the largest NF1 centers in the U.S., the NYU Comprehensive Neurofibromatosis Center.

Inclusion Criteria:

• Children who are independently ambulatory who meet revised diagnostic criteria for NF1
• Children less than or equal to 71 months of age
• Parent/Legal Guardian willing and able to provide parental consent.

Exclusion Criteria:

• Age ≥ 6 years old, inability to walk 10 meters independently, non-NF1 medical illness that alters their physical or neurological abilities that could significantly impact their performance.
• Parent/Legal Guardian not willing and able to provide parental consent

Children who are independently ambulatory who meet revised diagnostic criteria for NF1

The de-identified participant data from the final research dataset will be shared upon reasonable request immediately following publication, with no end date, or as required by a condition of awards or supporting agreements. The protocol and statistical analysis plan will be posted on Clinicaltrials.gov only as required by federal regulation or supporting awards and agreements.

Immediately following publication. No end date.

The investigator who proposed to use the data will be granted access upon reasonable request. Data are available for 5 years at a third party website (Link to be included).