[Value of karyotype in vascular acrosyndromes].

The evolution of Raynaud's phenomenon may, when clinical manifestations and capillaroscopy evoke the diagnosis of systemic disease, cause to consider performing a karyotype. In these cases, abnormalities are frequent, and 10% of these abnormalities must cause to suspect a collagen disease. The presence of the breaking factor is not the only etiology of these frequent abnormalities and a very thorough investigation must be made in order to rule out an extrinsic or idiopathic cause. Difficult to perform, it requires a highly specialized laboratory and demonstrates all its advantages in the etiological diagnosis of Raynaud's phenomenon.