Brachymetacarpia V in familial short stature

This study was planned to search for the presence of possible tubular bone abnormalities in familial short stature (FSS) as has been previously noted in some reports. Twenty-five (17 male, 8 female) children with FSS aged 10.0 SD 3.6 years were taken as the study group, and 23 (14 male, 9 female) children of normal stature aged 10.6 SD 2.7 years comprised the control group. FSS was defined as height of the child and mean parental height below 3rd centile line, normal growth velocity and bone age within 2 years of chronological age. Other causes of short stature were ruled out. Height, weight, sitting height and arm, forearm and upper arm length measurements were taken by standard methods. A left hand and wrist X-ray was taken to evaluate the length of the 5th metacarpal. Children with FSS had a significantly higher prevalence of brachymetacarpia V (64%) than the children with normal stature (21.7%) (p < 0.001). Other tubular bone parameters, however, were normal. Sitting height/height ratios were in normal ranges and comparable in FSS and the control group. Similarly arm to height and upper arm to forearm ratios were comparable in the two groups excluding disproportionate shortening of the limbs. The finding of increased incidence of brachymetacarpia V in FSS may suggest an underlying tubular bone abnormality, which may explain the short stature in FSS.