Trisomy 9p, a chromosome aberration with distinct radiologic findings.

Radiographic analysis of 33 cases of trisomy 9p (21 familial, 12 nonfamilial) disclosed consistent abnormalities in the hands, feet, and pelvic bones, with one exception (subsequently considered a misdiagnosis). Most of the abnormalities were present only during the period of epiphyseal growth and occurred with similar frequency in both familial and nonfamilial cases. There was no correlation between the severity of osseous involvement and the amount of trisomic chromosomal material. The pattern of radiographic findings in trisomy 9p appears to be unique, at least among chromosome aberrations, and may help in establishing a specific diagnosis in nonfamilial cases.