CARNEY–STRATAKIS SYNDROME (CARNEY DYAD; DYAD OF PARAGANGLIOMAS AND STROMAL TUMOURS)
Carney–Stratakis syndrome (CSS) or Carney dyad should not be confused with the more classic Carney triad, the latter of which comprises paragangliomas (PGL), gastrointestinal stromal Tumours (GIST), and pulmonary chondromas. In contrast to Carney triad which occurs sporadically, CSS is an autosomal dominant condition characterized by PGL or pheochromocytoma and GIST (Stratakis and Carney 2009). Recently, germline heterozygous mutations in SDHB, SDHC, or SDHD, encoding three of the four subunits of succinate dehydrogenase (mitochondrial complex II), were found in individuals and families with CSS (McWhinney et al. 2007; Pasini et al. 2008). In this initial series, 8 of 11 CSS individuals harbored SDH mutations. At this time, it is difficult to determine whether individuals with PGL and GIST but who are SDH mutation negative actually have Carney triad but have yet to develop the third component (Alrashdi et al. 2010). Because of the rarity of CSS and the short time from discovery of its genetic basis, one must assume that medical management and surveillance are similar to that recommended for those with PGL/pheochromocytoma syndromes caused by germline mutations in SDHA-D genes.