The phenotype of 45,X females: an anthropometric quantification

Twenty-five anthropometric measurements were recorded from 48 adult 45,X females, 24 of their first-degree female relatives, and 95 control females. When 45,X females were compared with their female relatives and control females they were smaller in most dimensions, the largest differences being found in weight, stature, sitting height, arm length, leg length, bi-iliac diameter, bitrochanteric breadth and wrist width. No significant differences were found in head dimensions. The comparison after allowance for size showed that 45,X females are relatively smaller in stature, sitting height, arm length, leg length and bitrochanteric breadth and larger in bideltoid breadth, waist breadth, upper arm circumference, chest circumference and triceps skinfold. However, in proportion to height the relative lengths of sitting height, arm length and leg length were similar to those of normal females. The mother-45,X daughter correlation coefficients were significantly larger than those of sister-45,X sister pairs in body dimensions whereas they were more similar in head dimensions. The present findings suggest the presence of genes on the X chromosome having effect on growth in general. This conclusion is in accordance with the results of several earlier studies which have indicated an X-chromosomal influence on stature, tooth size and enamel thickness.