The Coffin-Siris syndrome.

A 14-month-old female with the Coffin-Siris syndrome is described. Typical features included underweight at birth, growth retardation, microcephaly, profound mental retardation, severe hypotonia with lax joints, feeding difficulties and frequent respiratory tract infections; sparce scalp hair, small nose, epicanthic folds, a prominent philtrum and full lips; a congenital heart defect; hypoplasia or aplasia of the distal phalanges of digits 2--5 and the corresponding nails, especially of the fifth fingers and toes, and aplasia of the middle phalanges of the little fingers and the second and fifth toes; severe delay in bone maturation. The proposita also showed hypoplasia of the lateral portions of both clavicles. Inheritance of the Coffin-Siris syndrome is possibly autosomal recessive.