Chromosome 15 in floppy infants.

The daily urine output may be of low volume during the first few days of life especially in low birthweight infants. To lessen urine loss we apply silicone oil to all the drainage surfaces of the tray and scrape retained droplets of urine towards the drainage pipe using the rubber blade of a small window cleaner. Evaporative losses are reduced by nursing the child in humidified air. There is no discomfort to the infant and the method is ethically and socially acceptable. Mothers can breast feed their infants under supervision, while any urine voided during the feed can be collected in a warmed receptacle placed under the female infant's buttocks, or positioned over the penis. This device has greatly improved the accuracy and acceptability of prolonged urine collection for clinical and, especially, research purposes. The original model was constructed in stainless steel but it could be reproduced, in most research workshops, from a lighter and cheaper moulded plastic or Perspex. We thank the Department of Medical Illustration for the photographs and Miss D Davis and Miss Rose-Marie Aikens for advice. The apparatus was constructed by Lawry Brice. References Clifton J. Collecting 24 hour urine specimens from infants. SUMMARY Three children with Prader-Willi syndrome and chromosome abnormalities affecting chromosome 15 are described and the literature is reviewed. The usefulness of chromosome analysis in the investigation of the floppy infant is illustrated by two of the cases described. Twenty-three other children with similar clinical features had normal chromosomes. The association of apparently balanced chromosome rearrangements involving chromosome 15 with Prader-Willi syndrome has been reported pre-viouslyl-5 We wish to describe for the first time the presence of a Y/15 translocation in a boy with this syndrome, and we also wish to describe 2 girls who presented in the neonatal period with extreme hypotonia and who too were found to have balanced translocations ofchromosome 15. Case reports Case 1. This was the first son of healthy, unrelated parents who were each aged 26 years at the time of his birth. He has one healthy brother and his mother has had no miscarriages, He was a term, breech delivery and weighed 2-7 kg at birth. He was noted to be very floppy as an infant and did not sit unaided until age 18 months. No information is available about early feeding habits but he started to gain excess weight at about 9 months. He has …