Candidate loci for Zimmermann-Laband syndrome at 3p14.3.

A male with 46,XY,t(3;17)(p14.3;q24.3) presented with gingival hyperplasia, hypertrichosis, unusually large ears and marked hypertrophy of the nose, characteristic of the Zimmermann-Laband syndrome (ZLS). Other features include large facial bones and mandibles, large protruding upper lip, enlarged fingers and toes, strabismus, and enlarged phallus. Knowledge of a 46,XX,t(3;8)(p21.2;q24.3) reported previously in a mother and daughter with ZLS suggests that the 3p14.3-p21.2 region may contain a gene responsible for ZLS. We have reassessed the chromosome 3 breakpoint region of the t(3;8) and revised its breakpoint location to 3p14.3, based upon an updated human genome sequence assembly. Using fluorescence in situ hybridization (FISH) with BAC clones, we have also identified a breakpoint spanning clone at 3p14.3 in our t(3;17) patient, thereby narrowing the breakpoint to a region of approximately 200 kb. These data suggest that the gene responsible for ZLS is located in 3p14.3 and implicates four likely candidate genes in this region: CACNA2D3, encoding a voltage-dependent calcium channel, LRTM1, a gene of unknown function embedded within CACNA2D3, WNT5A, encoding a secreted signaling protein of the WNT family, and ERC2, which codes for a synapse protein.