RESUMO
BACKGROUND: Turner syndrome is hypothesized to result from haploinsufficiency of certain genes expressed from both sex chromosomes that escape X inactivation. CASE REPORT: We present the rare case of a 4-year-old boy who was referred to the pediatric endocrinology unit for evaluation of slight growth delay. RESULTS: Standard cytogenetic analysis showed a 45,XO karyotype. Molecular studies disclosed the presence of an intact SRY homeobox region and the ZFY region sited on the Y short arm. Other Y chromosome sequences which are normally found on the short arm of chromosome Y (p) were absent and their exact location on a different chromosome remained unclear. Subsequently, FISH (fluorescent in situ hybridization) analysis failed to detect any Y sequences, while haplotype analysis indicated that the present X chromosome was of paternal origin. CONCLUSION: Phenotype-genotype correlation studies were consistent with a male patient presenting with short stature and some of the Turner's syndrome stigmata. The consequences for the patients with this chromosomal abnormality and treatment with recombinant growth hormone are also discussed.
