A rare syndrome characterized by hard, thick skin, usually on the entire body. The thickening of the skin can limit joint mobility and causes joints to be stuck in a bent position (flexion contractures). The onset of signs and symptoms can range from presenting at birth through childhood. Other signs and symptoms may include excessive hair growth (hypertrichosis), loss of body fat (lipodystrophy), scoliosis, muscle weakness, slow growth, and short stature. Weakness or paralysis of the eye muscles have also been reported. Stiff skin syndrome is caused by mutations (changes) in the FBN1 gene and is inherited in an autosomal dominant manner. Diagnosis is based on a clinical evaluation that is consistent with stiff skin syndrome, and the diagnosis can be confirmed with genetic testing. Treatment is based on the symptoms of each individual and may include physical therapy. The disease is Monarch Disease Ontology entry MONDO_0008492 (stiff skin syndrome).