[PDF][PDF] RAB23 mutations in Carpenter syndrome imply an unexpected role for hedgehog signaling in cranial-suture development and obesity

D Jenkins, D Seelow, FS Jehee, CA Perlyn… - The American Journal of …, 2007 - cell.com
D Jenkins, D Seelow, FS Jehee, CA Perlyn, LG Alonso, DF Bueno, D Donnai, D Josifiova…
The American Journal of Human Genetics, 2007cell.com
Carpenter syndrome is a pleiotropic disorder with autosomal recessive inheritance, the
cardinal features of which include craniosynostosis, polysyndactyly, obesity, and cardiac
defects. Using homozygosity mapping, we found linkage to chromosome 6p12. 1-q12 and,
in 15 independent families, identified five different mutations (four truncating and one
missense) in RAB23, which encodes a member of the RAB guanosine triphosphatase
(GTPase) family of vesicle transport proteins and acts as a negative regulator of hedgehog …
Carpenter syndrome is a pleiotropic disorder with autosomal recessive inheritance, the cardinal features of which include craniosynostosis, polysyndactyly, obesity, and cardiac defects. Using homozygosity mapping, we found linkage to chromosome 6p12.1-q12 and, in 15 independent families, identified five different mutations (four truncating and one missense) in RAB23, which encodes a member of the RAB guanosine triphosphatase (GTPase) family of vesicle transport proteins and acts as a negative regulator of hedgehog (HH) signaling. In 10 patients, the disease was caused by homozygosity for the same nonsense mutation, L145X, that resides on a common haplotype, indicative of a founder effect in patients of northern European descent. Surprisingly, nonsense mutations of Rab23 in open brain mice cause recessive embryonic lethality with neural-tube defects, suggesting a species difference in the requirement for RAB23 during early development. The discovery of RAB23 mutations in patients with Carpenter syndrome implicates HH signaling in cranial-suture biogenesis—an unexpected finding, given that craniosynostosis is not usually associated with mutations of other HH-pathway components—and provides a new molecular target for studies of obesity.
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