title: High-resolution cytogenetic studies in patients with Prader-Willi syndrome.
abstract: We investigated 24 patients with Prader-Willi syndrome by the high-resolution banding technique. Their history and clinical findings were also examined in some detail. Twelve had interstitial deletion of 15q; del(15) (q11.2q13) in 11 cases and del(15) (q11.2q12) in one case. Six revealed normal karyotypes at about 500-850 bands per haploid-set level. In an additional six cases, no deletion was detected. However, we took the results as tentative, as the observed karyotypes were at the 400-bands level. During the course of this study, it was realized that a small deletion in the proximal 15q could be easily overlooked when a mitotic spread around 400-bands or less per haploid-set level was used. There was no distinct difference in the clinical features of patients with interstitial deletion and those with a normal karyotype. Two cases in the latter group lacked some of the typical features of the former group, e.g. poor fetal vigor, neonatal feeding difficulty, hypotonia, and delayed motor development.
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002871:Chromosome Banding; D002872:Chromosome Deletion; D002884:Chromosomes, Human, Pair 15; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D010641:Phenotype; D011218:Prader-Willi Syndrome / Q000235:genetics*