Three sisters with 3-M slender-boned nanism are described. The main features were low birth weight, disproportionate dwarfism, large head for height, triangular-shaped face with wide anteverted nostrils, long philtrum and full lips, short neck, elbow malformation, pes planus with prominent heels, slender bones with thin diaphyses, small pelvis, and mild mental deficiency. Comparative analysis with the eight other cases reported in the literature permits further clinical delineation and the corroboration of autosomal recessive inheritance.