Increasing role of cytogenetics in pediatric practice.

Karyotyping was done in 100 children suspected of having chromosomal abnormalities of genetically uncertain syndromes, multiple congenital anomalies, short stature, dysmorphic features, unclassified mental retardation, and Down syndrome. A total of 56 patients had an abnormal karyotype: ring chromosome of 13 was seen in 1 patient (1.78%), and trisomy 21 was seen in 29 patients (51.