A patient with 45,XX,Gminus-46,XX,Gr mosaicism.

She was an only child born when her mother was 26 and her father was 44 years of age. Her birthweight was 2850 g. She was admitted at 23 weeks of age because of failure to thrive. Her weight increments had been slow throughout, and at 23 weeks of age she weighed only 4875 g., which was a long way below the 10th percentile. She was short of breath, and there was clinical and radiological evidence of cardiac enlargement, but she did not have a cardiac murmur. Cardiac catheterization showed the presence ofa large persistent ductus arteriosus. This was ligated at 35 weeks of age and she made an uneventful recovery. There was delay in mental development, which was not severe at first. At 23 weeks of age she was laughing loudly, vocalizing actively, able to go for objects and grasp them, though not able to transfer from hand to hand. Her facial appearance suggested mongolism (Fig. 1) though this was by no means clear cut, and in a large gathering of paediatricians, opinion was about equally divided whether she was a mongol or not. Her head was short and broad, though not flattened posteriorly. Circumference 38 cm. was well below the 10th percentile and was small even in relation to her weight. She had a suggestion of mongoloid epicanthic folds and her palpebral fissures were slanting upwards and outwards. Shape of the mouth was, however, normal, the tongue was not scrotal, and Brushfield spots were absent. Ears and lower jaw were of normal size and shape. Though there was a single palmar crease on the left hand (Fig. 2), the right palm was normal. Little fingers were not incurved or short, and two interphalangeal creases were present. Finger-nails were normal. The gap between the first and second digits of the feet was not exaggerated. A radiograph of her pelvis did not show mongoloid changes. Dermatoglyphic patterns were not informative. Muscle tone appeared normal.