A terminal transverse limb reduction defect is a relatively common congenital malformation that most often occurs unilaterally and in isolation. A mildly mentally disabled boy is described with an absent left hand, a congenital cardiac defect, short stature, facial dysmorphism and skin pigmentary anomalies. Karyotyping of fibroblasts revealed mosaic trisomy 22. Most of the clinical features of our patient are consistent with the phenotype of mosaic trisomy 22, however, a terminal transverse reduction defect has until now never been reported in association with this chromosomal aberration.