Oculodentodigital dysplasia: study of ophthalmological and clinical manifestations in three boys with probably autosomal recessive inheritance

Novel mutations in GJA1 in two Brazilian families with oculodentodigital dysplasia

Oculodentodigital dysplasia (ODDD; MIM #164200), a rare genetic disorder characterized by abnormal craniofacial, dental, ocular, and digital features, is caused by mutations in GJA1 (gap junction alpha-1) gene and inherited in an autosomal dominant pattern. However, an autosomal recessive pattern is also reported. Here we described 2 families with members affected by ODDD. In the first family, the c.752G>C (p.S251T) and c.848C>T (p.P283L) heterozygous missense mutations and the c.825C>T (p.T275T) silent mutation were identified in the proband, which showed mild ODDD phenotypes, and in his mother, which displayed hemolytic anemia and thrombocytopenia. In the second family, the patients displayed typical features of ODDD, and Sanger sequencing identified a novel homozygous c.604C>T (p.R202C) missense mutation, whereas the parents carried the mutation. Together, these findings suggest that homozygous mutation in GJA1 induces a more severe ODDD phenotype, though interfamilial phenotype variability was observed, whereas compound heterozygous mutations in GJA1 cause a mild phenotype.

Oculodentodigital Dysplasia: A Case Report and Major Review of the Eye and Ocular Adnexa Features of 295 Reported Cases

Oculodentodigital dysplasia (ODDD) is a rare genetic disorder associated with a characteristic craniofacial profile with variable dental, limb, eye, and ocular adnexa abnormalities. We performed an extensive literature review to highlight key eye features in patients with ODDD and report a new case of a female patient with a heterozygous missense GJA1 mutation (c.65G>A, p.G22E) and clinical features consistent with the condition. Our patient presented with multiple congenital anomalies including syndactyly, microphthalmia, microcornea, retrognathia, and a small nose with hypoplastic alae and prominent columella; in addition, an omphalocele defect was present, which has not been reported in previous cases. A systematic review of the published cases to date revealed 91 literature reports of 295 individuals with ODDD. There were 73 different GJA1 mutations associated with these cases, of which the most common were the following missense mutations: c.605G>A (p.R202H) (11%), c.389T>C (p.I130T) (10%), and c.119C>T (p.A40V) (10%). Mutations most commonly affect the extracellular-1 and cytoplasmic-1 domains of connexin-43 (gene product of GJA1), predominately manifesting in microphthalmia and microcornea. The syndrome appears with an approximately equal sex ratio. The most common eye features reported among all mutations were microcornea, microphthalmia, short palpebral fissures, and glaucoma.

Autosomal Recessive Oculodentodigital Dysplasia: A Case Report and Review of the Literature

Oculodentodigital dysplasia (ODDD) is a rare condition characterized by a typical facial appearance and variable findings of the eyes, teeth, and fingers. ODDD is caused by mutations in the GJA1 gene in chromosome 6q22 and inherited in an autosomal dominant manner in the majority of the patients. However, in recent clinical reports, autosomal recessive ODDD cases due to by GJA1 mutations were also described. Here, we report on a 14-year-old boy with microphthalmia, microcornea, narrow nasal bridge, hypoplastic alae nasi, prominent columnella, hypodontia, dental caries, and partial syndactyly of the 2nd and 3rd toes. These clinical findings were concordant with the diagnosis of ODDD, and a novel homozygous mutation (c.442C>T, p.Arg148Ter) was determined in the GJA1 gene leading to a premature stop codon. His phenotypically normal parents were found to be carriers of the same mutation. This is the third family in the literature in which ODDD segregates in an autosomal recessive manner.

Delineation of Novel Autosomal Recessive Mutation in GJA3 and Autosomal Dominant Mutations in GJA8 in Pakistani Congenital Cataract Families

Congenital cataract is a clinically and genetically heterogeneous disease. The present study was undertaken to find the genetic cause of congenital cataract families. DNA samples of a large consanguineous Pakistani family were genotyped with a high resolution single nucleotide polymorphism Illumina microarray. Homozygosity mapping identified a homozygous region of 4.4 Mb encompassing the gene GJA3. Sanger sequence analysis of the GJA3 gene revealed a novel homozygous variant c.950dup p.(His318ProfsX8) segregating in an autosomal recessive (AR) manner. The previously known mode of inheritance for GJA3 gene mutations in cataract was autosomal dominant (AD) only. The screening of additional probands (n = 41) of cataract families revealed a previously known mutation c.56C>T p.(Thr19Met) in GJA3 gene. In addition, sequencing of the exon-intron boundaries of the GJA8 gene in 41 cataract probands revealed two additional mutations: a novel c.53C>T p.(Ser18Phe) and a known c.175C>G p.(Pro59Ala) mutation, both co-segregating with the disease phenotype in an AD manner. All these mutations are predicted to be pathogenic by in silico analysis and were absent in the control databases. In conclusion, results of the current study enhance our understanding of the genetic basis of cataract, and identified the involvement of the GJA3 in the disease etiology in both AR and AD manners.

A novel GJA1 mutation in oculodentodigital dysplasia with progressive spastic paraplegia and sensory deficits

Oculodentodigital dysplasia (ODDD) is a rare autosomal dominant inherited disorder mainly affecting the development of the face, eyes, dentition, limbs, hair and heart. GJA1 (the gap junction protein α-1) has been determined to be a causative gene of ODDD, mapped to chromosome 6q22-24 identified as the connexin 43 gene (Cx43). We found a novel GJA1 mutation (W25C) as the possible causative gene in this sporadic ODDD patient with neurological features of motor deficits by pyramidal tract signs, and sensory deficits due to peripheral nerve disturbance. It is also notable that the MRI of this patient demonstrated widespread aberrant signal lesions in the brain and brainstem.

[Hereditary glaucoma associated with oculodentodigital dysplasia]

CASE REPORT

A newborn evaluated at 20 days old due to occasional nystagmus. Her mother had presented with oculodentodigital dysplasia (ODDD) and glaucoma. The physical examination revealed opaque micro-corneas, and horizontal nystagmus. The tonometry showed 35 mm Hg in OD and 40 mm Hg in OS and the fundus examination was normal. She had a narrow nasal bridge with narrow nostrils, and fourth and fifth finger syndactylyl in both hands. A bilateral trabeculectomy was performed with a good response.

DISCUSSION

ODDD is a rare autosomal dominant disease with heterogeneous phenotype manifestations. The most frequent cause of loss of visual acuity is the glaucoma, requiring long-term follow up with periodical control of the intraocular pressure (IOP).

Tyrosine-dependent basolateral targeting of human connexin43-eYFP in Madin-Darby canine kidney cells can be disrupted by the oculodentodigital dysplasia mutation L90V

Polarized membrane sorting of connexin 43 (Cx43) has not been well-characterized. Based on the presence of a putative sorting signal, YKLV(286-289), within its C-terminal cytoplasmic domain, we hypothesized that Cx43 is selectively expressed on the basolateral surface of Madin-Darby canine kidney (MDCK) cells in a tyrosine-dependent manner. We generated stable MDCK cell lines expressing human wild-type and mutant Cx43-eYFP, and analyzed the membrane localization of Cx43-eYFP within polarized monolayers using confocal microscopy and selective surface biotinylation. We found that wild-type Cx43-eYFP was selectively targeted to the basolateral membrane domain of MDCK cells. Substitution of alanine for Y286 disrupted basolateral targeting of Cx43-eYFP. Additionally, substitution of a sequence containing the transferrin receptor internalization signal, LSYTRF, for PGYKLV(284-289) also disrupted basolateral targeting. Taken together, these results indicate that Y286 in its native amino acid sequence is necessary for targeting Cx43-eYFP to the basolateral membrane domain of MDCK cells. To determine whether the F52dup or L90V oculodentodigital dysplasia-associated mutations could affect polarized sorting of Cx43-eYFP, we analyzed the expression of these Cx43-eYFP mutant constructs and found that the L90V mutation disrupted basolateral expression. These findings raise the possibility that some oculodentodigitial dysplasia-associated mutations contribute to disease by altering polarized targeting of Cx43.

A case of oculodentodigital dysplasia syndrome with novel GJA1 gene mutation

PURPOSE

To report a case of oculodentodigital dysplasia syndrome (ODDD) with a heterozygous mutation in GJA1 (connexin 43) gene.

METHODS

A 9-year-old girl visited our hospital complaining of visual disturbances. The patient had microphthalmia, a small nose with hypoplastic alae nasi, and syndactyly. Visual acuity with prescribed glasses improved to 0.5 (1.2) OU 2 months after the first visit. She was satisfied with the new glasses and the improvement in visual acuity. Genomic DNA was extracted from leukocytes of the patient's peripheral blood in accordance with standard procedures, after obtaining parental informed consent. We amplified GJA1 exon 2 from her genomic DNA by the PCR method, and sequenced the product using the dye terminator method.

RESULTS

S5C (c. 13A > T), a novel mutation in exon 2 of GJA1, was found in the patient. The parents had no mutation of GJAI, nor was there any sign of abnormality in other family members. No similar mutation could be found in the 50 genotyped normal subjects in the control group.

CONCLUSIONS

A novel GJA1 mutation was detected in a Japanese ODDD patient. Glaucoma complications associated with ODDD have already been reported. Careful long-term monitoring and treatment are also necessary.

Variable expression of neurological phenotype in autosomal recessive oculodentodigital dysplasia of two sibs and review of the literature

Individuals with oculodentodigital dysplasia (ODDD) have a characteristic facial appearance and variable involvement of the eyes, teeth and fingers. Gutmann et al. (Am J Med Genet 41:18, 1990) drew attention to neurological symptoms as a feature in a proportion of individuals with ODDD and demonstrated white matter changes on cranial magnetic resonance imaging. The majority of cases described previously have family histories compatible with autosomal dominant inheritance. Until now, five families have been reported where autosomal recessive inheritance is more likely. Neurological symptoms were described in only one of these families but cerebral imaging was not performed. We describe clinical, including neurological and radiological findings, in two sisters with autosomal recessive ODDD.

Okulodentodigitale Dysplasie

Die seltene Erkrankung okulodentodigitale Dysplasie (ODDD), die in der Regel autosomal-dominant vererbt wird, ist charakterisiert durch Veränderungen der Augen, Zähne und der Finger und geht auf eine Mutation des GJA1-Gens zurück. Im Hinblick auf die Zahnveränderungen ist ein früher Zeitpunkt für Beurteilung und Behandlung von entscheidender Bedeutung. Im vorliegenden Fallbericht wird dargestellt, dass an verschiedenen Zähnen unterschiedlich stark ausgeprägte Veränderungen erkennbar werden können. Dies könnte erklären, dass in der Literatur die Zahnveränderungen bei ODDD so unterschiedlich beschrieben werden.

Differential potency of dominant negative connexin43 mutants in oculodentodigital dysplasia

Oculodentodigital dysplasia (ODDD) is a congenital autosomal dominant disorder with phenotypic variability, which has been associated with mutations in the GJA1 gene encoding connexin43 (Cx43). Given that Cx43 mutants are thought to be equally co-expressed with wild-type Cx43 in ODDD patients, it is imperative to examine the consequence of these mutants in model systems that reflect this molar ratio. To that end, we used differential fluorescent protein tagging of mutant and wild-type Cx43 to quantitatively monitor the ratio of mutant/wild-type within the same putative gap junction plaques and co-immunoprecipitation to determine if the mutants interact with wild-type Cx43. Together the fluorescence-based assay was combined with patch clamp analysis to assess the dominant negative potency of Cx43 mutants. Our results revealed that the ODDD-linked Cx43 mutants, G21R and G138R, as well as amino terminus green fluorescent protein-tagged Cx43, were able to co-localize with wild-type Cx43 at the gap junction plaque-like structures and to co-immunoprecipitate with wild-type Cx43. All Cx43 mutants demonstrated dominant negative action on gap junctional conductance of wild-type Cx43 but not that of Cx32. More interestingly, these Cx43 mutants demonstrated different potencies in inhibiting the function of wild-type Cx43 with the G21R mutant being two times more potent than the G138R mutant. The potency difference in the dominant negative properties of ODDD-linked Cx43 mutants may have clinical implications for the various symptoms and disease severity observed in ODDD patients.

Cowden disease: a review

Cowden disease is a genetically inherited disorder presenting with multiple hamartomatous and neoplastic lesions in various organs and tissues. We present a review of the diagnostic criteria, clinical presentation, genetics, and management of this condition.

A nonsense mutation in the first transmembrane domain of connexin 43 underlies autosomal recessive oculodentodigital syndrome

BACKGROUND

Oculodentodigital syndrome (ODD) is a pleiotropic congenital disorder characterised by abnormalities of the face, eyes, dentition, and limbs. ODD, which is inherited as an autosomal dominant trait, results from missense mutations in the gap junction protein connexin 43.

OBJECTIVE

To analyse a family with a history of ODD which is inherited in an autosomal recessive manner

RESULTS

ODD in this family resulted from the homozygous mutation R33X in the first transmembrane domain of connexin 43.

CONCLUSIONS

The findings provide clear genetic evidence that ODD can be inherited in an autosomal recessive manner and that a dominant negative mechanism underlies autosomal dominant ODD.

Functional Characterization of aGJA1Frameshift Mutation Causing Oculodentodigital Dysplasia and Palmoplantar Keratoderma

A frameshift mutation generated from a dinucleotide deletion (780-781del) in the GJA1 gene encoding Cx43 results in a frameshift yielding 46 aberrant amino acids after residue 259 and a shortened protein of 305 residues compared with the 382 in wild-type Cx43. This frameshift mutant (fs260) causes oculodentodigital dysplasia (ODDD) that includes the added condition of palmoplantar keratoderma. When expressed in a variety of cell lines, the fs260 mutant was typically localized to the endoplasmic reticulum and other intracellular compartments. The fs260 mutant, but not the G138R ODDD-linked Cx43 mutant or a Cx43 mutant truncated at residue 259 (T259), reduced the number of apparent gap junction plaques formed from endogenous Cx43 in normal rat kidney cells or keratinocytes. Interestingly, mutation of a putative FF endoplasmic reticulum retention motif encoded within the 46 aberrant amino acid domain failed to restore efficient assembly of the fs260 mutant into gap junctions. Dual whole cell patch-clamp recording revealed that fs260-expressing N2A cells exerted severely reduced electrical coupling in comparison to wild-type Cx43 or the T259 mutant, whereas single patch capacitance recordings showed that fs260 could also dominantly inhibit the function of wild-type Cx43. Co-expression studies further revealed that the dominant negative effect of fs260 on wild-type Cx43 was dose-dependent, and at a predicted 1:1 expression ratio the fs260 mutant reduced wild-type Cx43-mediated gap junctional conductance by over 60%. These results suggest that the 46 aberrant amino acid residues associated with the frameshift mutant are, at least in part, responsible for the manifestation of palmoplantar keratoderma symptoms.