Serpentine fibula-polycystic kidney syndrome (SFPKS; MIM 102500) is a rare, autosomal dominant disorder caused by mutations in the NOTCH2 gene.  SFPKS shares many phenotypic characteristics with Hajdu-Cheney syndrome (HJCYS; MIM 102500), another disorder caused by truncating mutations in the last exon of NOTCH2. Clinical features in individuals with SFPKS include polycystic kidneys, elongated and bowed fibulae, osteoporosis, spontaneous fractures, wormian bones, short stature, mild facial dysmorphism, Pierre Robin sequence, conductive hearing loss, and mild delays in motor development.  Acro-osteolysis has been reported in some patients with SFPKS and the clinical overlap with HJCYS suggests that these syndromes represent a continuum rather than discrete disorders.  Melnick-Needles syndrome (MNS; MIM 309350) may also be considered in differential diagnosis for SFPKS.