The Problem of Trisomy 22

A case of trisomy 22 with partial long arm deletion (47, +22 q-) studied by G-banding is presented. The patient, a five-month-old male, showed failure to thrive, delayed psychomotor development, large, low-set ears, mild micrognathia, atrial septal defect, and marked muscular hypotonia. The father's karyotype was normal. The mother's karyotype was 46 XX, but one of the no22 chromosomes showed a deletion of the long arm as seen in the proband's karyotype. A comparison with previously reported cases in the literature indicates a great variability of clinical features of trisomy 22: "classical form," cat eye syndrome, and abortive cases (as this reported case).