{Reference Type}: Case Reports {Title}: A 24-Year-Old Man With Spastic Ataxia and Hypodontia. {Author}: Marien L;Tsitsi P;Cypers G; {Journal}: JAMA Neurol {Volume}: 81 {Issue}: 6 {Year}: 2024 Jun 1 {Factor}: 29.907 {DOI}: 10.1001/jamaneurol.2024.0890 {Abstract}: A 24-year-old man presented with progressive gait instability, marked spinal cord atrophy, and dental radiography showing the absence of several elements, microdontia, and taurodontia. What is your diagnosis?