This report describes hypoparathyroidism-retardation-dysmorphism syndrome. The human gene implicated in this disease is TBCE, which encodes a chaperone protein required for the proper folding of alpha-tubulin subunits and the formation of alpha-beta-tubulin heterodimers. This gene are also associated with the disease Kenny-Caffey syndrome, type 1 (MIM:244460). There is one high-scoring fly ortholog: Tbce, for which RNAi targeting constructs, alleles caused by insertional mutagenesis, and classical amorphic alleles have been generated. The human TBCE gene has not been introduced into flies.
For loss-of-function mutations in the Dmel\Tbce gene, observed phenotypes include aspects similar to the human disease, including changes in microtubule distribution; and aspects similar to the mouse disease model including axon growth defects. Phenotypic assays using the fly genes have allowed characterization of genetic interactions.
[updated October 2015 by FlyBase; FBrf0222196]
[HYPOPARATHYROIDISM-RETARDATION-DYSMORPHISM SYNDROME; HRDS](https://omim.org/entry/241410)
[TUBULIN FOLDING COFACTOR E; TBCE](https://omim.org/entry/604934)
HRD, also known as the Sanjad-Sakati syndrome, is an autosomal recessive syndrome of congenital hypoparathyroidism, mental retardation, facial dysmorphism and extreme growth failure reported almost exclusively in Middle Eastern populations. A similar syndrome with the additional features of osteosclerosis and recurrent bacterial infections is the autosomal recessive Kenny-Caffey syndrome. (Diaz, et al., 1999, pubmed:10377012) [from MIM:604934, 2015.02.11]
HRD can be caused by mutations in the gene encoding tubulin-specific chaperone E (TBCE). [from MIM:241410, 2015.02.11]
Analysis of diseased fibroblasts and lymphoblastoid cells showed lower microtubule density at the microtubule-organizing center (MTOC) and perturbed microtubule polarity in diseased cells. Immunofluorescence and ultrastructural studies showed disturbances in subcellular organelles that require microtubules for membrane trafficking, such as the Golgi and late endosomal compartments. (Parvari, et al., 2002, pubmed:12389028) [from MIM:604934, 2015.02.11]
The TBCE gene encodes one of several chaperone proteins required for the proper folding of alpha-tubulin subunits and the formation of alpha-beta-tubulin heterodimers. (Parvari, et al., 2002, pubmed:12389028) [from MIM:604934, 2015.02.11]
One to one: 1 human to 1 Drosophila (See DIOPT, link below).
Ortholog of human TBCE (1 Drosophila to 1 human).
Dmel\Tbce shares 32% identity and 51% similarity with human TBCE.
