Definition: The index overlaps a clenched fist formed by the other digits. The proximal interphalangeal articulation of the index is flexed and ulnarly deviated. The thumb is adducted. This attitude is constant during the examination and is strongly suggestive of trisomy 18.
Etiology
trisomy 18
FADS (fetal akinesia deformation sequence)
Differential diagnosis
Clenched hand must be differentiated from fixed attitudes observed in akinesia-hypokinesia syndromes and from a normal temporary closed fist.