A case of atelosteogenesis type III with bladder stone and proteinuria

Atelosteogenesis is a disease caused by mutations of FLNB gene encoding filamin B characterized by severe short-limbed dwarfism. FLNB-related disorders include atelosteognesis type I, Larsen syndrome, spondylocarpotarsal synostosis syndrome, and atelosteogensis type III. We report a case of atelosteogenesis type III who had bladder stone and proteinuria. While there have been no reports of kidney disease in these disorders1)2), filamin is an actin cross-linking protein, which functions as a scaffold for intracellular signaling pathway and protein transporting pathway3). Since filamin is ubiquitously expressed3)4), we speculated that proteinuria could be related to atelosteogensis type III. No renal pathology was detected, however, which led to the diagnosis of postural proteinuria. The bladder stone may also be related to the sitting position of the patient.