Hereditary chin quivering (Q98672)

Hereditary chin trembling is a rare autosomal dominant condition that has been linked to chromosome 9q13-21. characterised by paroxysmal, often rhythmic up-and-down movements of the chin and the lower lip. The episodes last from seconds to hours and may be triggered by emotion, anxiety, or may occur without apparent precipitants. The condition typically becomes manifest in infancy or in early life, and the episodes tend to reduce in frequency with advancing age.