Two Japanese siblings, a 2-year-old girl and a 7-month-old boy, had a syndrome of mental retardation, severe nasal hyp9plasia, peripheral dysostosis, and blue eyes. The mother showed nasal hyp9plasia of lesser degree and a mild form of peripheral dysostosis. This disorder bears a striking similarity to acrodysostosis, but in view of certain novel features its relationship to the disease is uncertain. The mode of inheritance could be either dominant with variable expressivity or autosomal recessive.