Hematological findings in Noonan syndrome

Rev Hosp Clin Fac Med Sao Paulo. 2003 Jan-Feb;58(1):5-8. doi: 10.1590/s0041-87812003000100002. Epub 2003 Apr 30.

Abstract

Objective: Noonan syndrome is a multiple congenital anomaly syndrome, and bleeding diathesis is considered part of the clinical findings. The purpose of this study was to determine the frequency of hemostatic abnormalities in a group of Noonan syndrome patients.

Method: We studied 30 patients with clinical diagnosis of Noonan syndrome regarding their hemostatic status consisting of bleeding time, prothrombin time, activated partial thromboplastin time and thrombin time tests, a platelet count, and a quantitative determination of factor XI.

Results: An abnormal laboratory result was observed in 9 patients (30%). Although coagulation-factor deficiencies, especially factor XI deficiency, were the most common hematological findings, we also observed abnormalities of platelet count and function in our screening.

Conclusions: Hemostatic abnormalities are found with some frequency in Noonan syndrome patients (30% in our sample). Therefore, we emphasize the importance of a more extensive hematological investigation in these patients, especially prior to an invasive procedure, which is required with some frequency in this disorder.

MeSH terms

  • Adolescent
  • Adult
  • Blood Coagulation Disorders / blood*
  • Blood Coagulation Disorders / complications
  • Child
  • Child, Preschool
  • Factor XI Deficiency / complications
  • Female
  • Hemorrhagic Disorders / etiology
  • Humans
  • Infant
  • Male
  • Noonan Syndrome / blood*
  • Noonan Syndrome / complications