Study: NCT05484570

Intervention type: OTHER
Intervention: Interval History
Description: The study coordinator or another team member will review standard health questions relevant to DNA repair disorders. The control group will not undergo an interval history. These questions will include:~1. How the participant's appetite and general weight trajectory has been since the last assessment~2. Any episodes of unexplained bleeding or bruising~3. Any jaundice~4. General level of alertness and interaction with family and others~5. Any changes in cognitive function such as speech, following commands, comprehension~6. Any changes in motor function, including the development of tremors and stiffness in movements

Intervention type: OTHER
Intervention: Physical Examination
Description: A board-certified neurologist (the principal investigator) will perform a general physical examination and a neurological examination and complete a standard CRF to document relevant findings. The control group will not undergo a physical examination.

Intervention type: OTHER
Intervention: ECAB Assessment
Description: An Early Clinical Assessment of Balance (ECAB) will be performed by the physical therapist. Part I can be assessed in all affected individuals, and Part II requires ambulation. For non-ambulatory individuals, only Part I will be applied. The items in the ECAB are summarized as follows:~Part I. Head and trunk postural control (maximum 36 points) Head righting - lateral (right and left) Head righting - extension Head righting - flexion Rotation in trunk (right and left) Equilibrium reactions in sitting (right and left) Protective extension - side Protection extension - backward Part II. Sitting and standing postural control (maximum 64 points) Sitting with back unsupported but feet supported on floor or on a stool Sitting to standing Standing unsupported with eyes closed Standing unsupported with feet together Turns 360 degrees Placing alternate foot on the step while standing unsupported

Intervention type: OTHER
Intervention: ECAB Assessment
Description: An Early Clinical Assessment of Balance (ECAB) will be performed by the physical therapist. Part I can be assessed in all affected individuals, and Part II requires ambulation. For non-ambulatory individuals, only Part I will be applied. The items in the ECAB are summarized as follows:~Part I. Head and trunk postural control (maximum 36 points) Head righting - lateral (right and left) Head righting - extension Head righting - flexion Rotation in trunk (right and left) Equilibrium reactions in sitting (right and left) Protective extension - side Protection extension - backward Part II. Sitting and standing postural control (maximum 64 points) Sitting with back unsupported but feet supported on floor or on a stool Sitting to standing Standing unsupported with eyes closed Standing unsupported with feet together Turns 360 degrees Placing alternate foot on the step while standing unsupported

Intervention type: OTHER
Intervention: Gait Assessment
Description: For ambulatory participants, the physical therapist will also assess standardized gait outcome measures, including:~1. Gait Speed: may be measured over a 10 meter distance, assessing both comfortable walking speed and fast walking speed~2. 10-meter walk/run: timed assessment at fastest gait attainable. This assessment would be omitted for those participants who are determined to have a high fall risk.~3. Timed Up and Go (TUG): time to stand from a chair, walk 3 meters, go around a cone, and return to the chair (with or without an assistive device)~4. Dynamic Gait Index (DGI): assesses 8 balance challenges while walking

Intervention type: OTHER
Intervention: Gait Assessment
Description: For ambulatory participants, the physical therapist will also assess standardized gait outcome measures, including:~1. Gait Speed: may be measured over a 10 meter distance, assessing both comfortable walking speed and fast walking speed~2. 10-meter walk/run: timed assessment at fastest gait attainable. This assessment would be omitted for those participants who are determined to have a high fall risk.~3. Timed Up and Go (TUG): time to stand from a chair, walk 3 meters, go around a cone, and return to the chair (with or without an assistive device)~4. Dynamic Gait Index (DGI): assesses 8 balance challenges while walking

Intervention type: OTHER
Intervention: Specimen Sample Collection
Description: Total blood volumes collected at each visit will be limited to 5mL/kg body weight, with a maximum of 18mL.~Saliva samples may be obtained if research is taking place where blood samples cannot be drawn or transferred.

Intervention type: OTHER
Intervention: Specimen Sample Collection
Description: Total blood volumes collected at each visit will be limited to 5mL/kg body weight, with a maximum of 18mL.~Saliva samples may be obtained if research is taking place where blood samples cannot be drawn or transferred.