Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Phenotypic variability of Turner syndrome (TS) challenges clinicians, and undiagnosed mosaicism may lead to conflicting results of karyotype-phenotype correlations. This study assessed the extent of phenotypic variability and investigated the presence of karyotype-phenotype correlations. Methods: The sample comprised 80 patients with >= 50 cells analyzed in karyotype. Twenty were 45, X/46, X,+ mar; three groups of 20 patients were constructed by matching those girls with the nearest-aged patient with 45, X, 45, X/46, XX and 45, X/46, X, i(Xq) or 46, X, i(Xq) karyotype. Results: Data were obtained on height z-score, dysmorphic features, echocardiogram and urinary system sonography. The number of dysmorphic features ranged from one to 16 and was not correlated to age at diagnosis or height. The groups did not differ in height, number of dysmorphic features, cardiovascular and urinary system anomalies and frequency of any specific feature, except for short fourth metacarpal. Conclusions: Wide phenotypical variability of TS may be objectively described and its clinical picture is not correlated to karyotype.29 475479Brazil's National Council for Scientific and Technological Development (CNPq/PIBIC)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)