Abstract
In the clinical genetics laboratory at Children's Hospital Medical Center, chromosome analysis is the procedure requested most frequently. Nearly 0.5 per cent of newborn infants have a chromosomal abnormality. Recommendations are made for selection of cases for this examination. Biochemical examination of urine also may be useful in identifying inborn errors of metabolism. Because methods are being developed to prevent the clinical manifestations of disorders such as galactosemia, phenylketonuria and Wilson's disease, early recognition is imperative.