TMEM67
Function
Required for ciliary structure and function. Part of the tectonic-like complex which is required for tissue-specific ciliogenesis and may regulate ciliary membrane composition (By similarity). Involved in centrosome migration to the apical cell surface during early ciliogenesis. Involved in the regulation of cilia length and appropriate number through the control of centrosome duplication. Is a key regulator of stereociliary bundle orientation (By similarity). Required for epithelial cell branching morphology. Essential for endoplasmic reticulum-associated degradation (ERAD) of surfactant protein C (SFTPC). Involved in the negative regulation of canonical Wnt signaling, and activation of the non-canonical cascade stimulated by WNT5A (PubMed:26035863). In non-canonical Wnt signaling, it may act as ROR2 coreceptor (By similarity).
Involvement in disease
TMEM67 mutations result in ciliary dysfunction leading to a broad spectrum of disorders, collectively termed ciliopathies. Overlapping clinical features include retinal degeneration, renal cystic disease, skeletal abnormalities, fibrosis of various organ, and a complex range of anatomical and functional defects of the central and peripheral nervous system. The ciliopathy range of diseases includes Meckel-Gruber syndrome, Bardet-Biedl syndrome, Joubert syndrome, and nephronophtisis among others. Single-locus allelism is insufficient to explain the variable penetrance and expressivity of such disorders, leading to the suggestion that variations across multiple sites of the ciliary proteome influence the clinical outcome.
Meckel syndrome 3
MKS3
A disorder characterized by a combination of renal cysts and variably associated features including developmental anomalies of the central nervous system (typically encephalocele), hepatic ductal dysplasia and cysts, and polydactyly.
None
The disease is caused by variants affecting the gene represented in this entry.
Joubert syndrome 6
JBTS6
A disorder presenting with cerebellar ataxia, oculomotor apraxia, hypotonia, neonatal breathing abnormalities and psychomotor delay. Neuroradiologically, it is characterized by cerebellar vermian hypoplasia/aplasia, thickened and reoriented superior cerebellar peduncles, and an abnormally large interpeduncular fossa, giving the appearance of a molar tooth on transaxial slices (molar tooth sign). Additional variable features include retinal dystrophy and renal disease.
None
The disease is caused by variants affecting the gene represented in this entry.
Bardet-Biedl syndrome 14
BBS14
A syndrome characterized by usually severe pigmentary retinopathy, early-onset obesity, polydactyly, hypogenitalism, renal malformation and intellectual disability. Secondary features include diabetes mellitus, hypertension and congenital heart disease. Bardet-Biedl syndrome inheritance is autosomal recessive, but three mutated alleles (two at one locus, and a third at a second locus) may be required for clinical manifestation of some forms of the disease.
None
The gene represented in this entry may act as a disease modifier. TMEM67 variations may influence the expression of Bardet-Biedl syndrome in patients who have causative mutations in other genes. Heterozygosity for a complex mutation in the TMEM67 gene coding for a protein with 2 in cis changes, and homozygosity for a truncating mutation of the CEP290 gene has been found in a patient with Bardet-Biedl syndrome 14.
COACH syndrome 1
COACH1
A form of COACH syndrome, a disorder characterized by cerebellar vermis hypoplasia, developmental delay, impaired intellectual development, ataxia, and hepatic fibrosis. Patients present the molar tooth sign, a midbrain-hindbrain malformation pathognomonic for Joubert syndrome and related disorders. Other features, such as coloboma and renal cysts, may be variable. COACH1 inheritance is autosomal recessive.
None
The disease is caused by variants affecting the gene represented in this entry.
Nephronophthisis 11
NPHP11
A disorder characterized by the association of nephronophthisis with hepatic fibrosis. Nephronophthisis is a progressive tubulo-interstitial kidney disorder histologically characterized by modifications of the tubules with thickening of the basement membrane, interstitial fibrosis and, in the advanced stages, medullary cysts. Typical clinical features are chronic renal failure, anemia, polyuria, polydipsia, isosthenuria, and growth retardation. Associations with extrarenal symptoms, especially ocular lesions, are frequent.
None
The disease is caused by variants affecting the gene represented in this entry.
RHYNS syndrome
RHYNS
An autosomal recessive syndrome characterized by gaze palsy, retinitis pigmentosa, sensorineural hearing loss, hypopituitarism, nephronophthisis, and skeletal dysplasia.
None
The disease is caused by variants affecting the gene represented in this entry.
Tissue Specificity
Widely expressed in adult and fetal tissues. Expressed at higher level in spinal cord.
Cellular localization
- Cell membrane
- Multi-pass membrane protein
- Endoplasmic reticulum membrane
- Multi-pass membrane protein
- Cell projection
- Cilium
- Cytoplasm
- Cytoskeleton
- Cilium basal body
- Localizes at the transition zone, a region between the basal body and the ciliary axoneme (PubMed:22121117).
Alternative names
MKS3, TMEM67, Meckelin, Meckel syndrome type 3 protein, Transmembrane protein 67