Gonadal dysgenesis (Turner's syndrome): short fourth metacarpal
The fourth metacarpal is often short in gonadal dysgenesis, as in this patient. Normally, a line tangential to the distal ends of the third and fifth metacarpals will transect the head of the fourth. If the fourth metacarpal is short, it will touch or lie below such a line. In gonadal dysgenesis the fifth metacarpal is often also short and occasionally the third metacarpal may be similarly affected. Premature fusion of the ossification centres of the involved metacarpals may be seen in young patients.
