METHODS

In this family, five affected individuals were found to have disproportionate dwarfism with similar clinical and radiological features. Patient 1 (figs 1 and 2) was born to healthy parents of Arabic-Muslim origin who are first cousins and of normal stature (father 175 cm (75th centile) and mother 168 cm (50th centile)), after a term pregnancy and normal delivery (birth weight 3100 g, birth length 45 cm (-2 SD), head circumference 33 cm). At 1 year, she had short-limbed short stature (height 68 cm (-3 SD), weight 8 kg (3rd centile), head circumference 43 cm (-3 SD), arm span 71 cm, palm length 5.2 cm (50th centile), middle finger length 3.2 cm (3rd centile)). Neurological examination, psychomotor development, hearing, and visual acuity were otherwise normal. Routine chemistry, thyroid function tests, and renal ultrasounds were normal as well. Re-evaluation at 6 years showed further disproportion of limbs, with bowed legs, waddling gait, wide joints (especially the knees), with limited elbow extension, pectus excavatum, and lumbar lordosis. At age 10 years, she underwent bilateral osteotomy of both proximal tibiae due to severe bowing. Examination at age 12 years showed the same changes (height at− 4 SD), severe waddling gait, and very pronounced bowing of lower limbs.