Expression of connexin-43 in the cardiac muscle of children diagnosed with hypoplastic left heart syndrome: a Western blot and confocal laser scanning microscopy study.

Hypoplastic left heart syndrome consists of several structural abnormalities in the left side of the heart and may be associated with a hereditary genetic cause, possibly related to the connexin gene GJA1; however, only a few studies have investigated it. The present study aimed to analyse the expression of connexin-43 in the cardiac muscle of hypoplastic left heart syndrome children by Western blot method and confocal laser scanning microscopy. For that, tissue samples were taken during corrective surgery to treat heart defects. Patients of control group (8) presented any type of heart defect not related to hypoplastic left heart syndrome, connexin-43, or its gene and those of hypoplastic left heart syndrome group (9) presented this disease singly, without any other associated congenital diseases. By means of confocal laser scanning microscopy, it was noticed no connexin-43 qualitative differences in positioning and location pattern between both groups. From Western blot analysis, the connexin-43 expression did not show a statistically significant difference (p = 0.0571) as well. Within the limits of this study, it is suggested that cardiomyocytes of hypoplastic left heart syndrome children are similar in connexin-43 location, distribution, and structural and conformational patterns to those of children with heart defects not related to this protein and its genes.

Anatomic and dynamic aspects of stomatognathic structures in osteogenesis imperfecta: a case report.

The osteogenesis imperfecta congenita (OMIM 166210) type II phenotype can be caused by mutation in either the COL1A1 gene or the COL1A2 gene that encode the chains of type I procollagen, the major protein in bones. Patients can therefore present a combination of features, including multiple long bone fractures and deformities, growth deficiency, joint laxity, hearing loss, blue sclera, and dentinogenesis imperfecta. The purpose of this study is to describe a clinical case of this syndrome, focusing on the anatomy of the temporomandibular joint (TMJ) that was assessed using computed tomography (CT) method. Clinical examination included evaluation of mandibular dynamics and investigation of temporomandibular dysfunction (TMD).

Two New Cases of 1p21.3 Deletions and an Unbalanced Translocation t(8;12) among Individuals with Syndromic Obesity.

Obesity is a highly heritable but genetically heterogeneous disorder. Various well-known microdeletion syndromes (e.g. 1p36, 2q37, 6q16, 9q34, 17p11.2) can cause this phenotype along with intellectual disability (ID) and other findings. Chromosomal microarrays have identified 'new' microdeletion/duplication syndromes often associated with obesity. We report on 2 unrelated patients with an overlapping region of deletion at 1p21.3p21.2, and a third patient with a de novo recurrent unbalanced translocation der(8)t(8;12)(p23.1;p13.31), detected by 180K array CGH in a prospective cohort of syndromic obesity patients. Deletion of 1p21.3 is a rare condition, and there have been only 11 cases of the same recurrent translocation between chromosomes 8 and 12 [t(8;12)] reported to date. The former has been associated with ID, autistic spectrum disorder (ASD) and mild dysmorphic features, and in 4 patients who were obese or had a tendency to obesity, a minimal overlapping region of 2 genes, DPYD and MIR137, was detected; t(8;12) has recently been recognized to cause a childhood obesity syndrome due to duplication of the GNB3 gene. Thus, our findings add to the existing literature on the clinical description of these new syndromes, providing additional support that these loci are associated with syndromic obesity. We suggest that heterozygous loss of MIR137 may contribute to obesity as well as ID and ASD.

Toxoplasma Gondii Infection of Chicken Embryos Causes Retinal Changes and Modulates HSP90B1 Gene Expression: A Promising Ocular Toxoplasmosis Model.

HSP90B1 is a gene that codifies heat shock protein 108 (HSP108) that belongs to a group of proteins induced under stress situation, and it has close relation with the nervous system, especially in the retina. Toxoplasma gondii causes ocular toxoplasmosis that has been associated with a late manifestation of the congenital toxoplasmosis although experimental models show that morphological alterations are already present during embryological development. Here, we used 18 eyes of Gallus domesticus embryos in 7th and 20th embryonic days to establish a model of congenital ocular toxoplasmosis, experimentally infected in its fifth day correlating with HSP90B1 gene expression. Embryos' eyes were histologically evaluated, and gene expression was performed by real-time polymerase chain reaction (PCR). Our data showed parasite present in the choroid, unusual migration of retinal pigment epithelium, and chorioretinal scars, and a tendency to a lower expression of the HSP90B1 gene upon experimental infection. This is a promising model to better understand T. gondii etiopathogeny.

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

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.

Further evidence of association between mutations in FGFR2 and syndromic craniosynostosis with sacrococcygeal eversion.

BACKGROUND: Pfeiffer syndrome (PS; OMIM #101600) is an autosomal dominant disorder characterized by craniosynostosis, midface hypoplasia, broad thumbs, brachydactyly, broad great toes, and variable syndactyly. CASE: We report a case of PS (type 3) with tracheal and visceral involvement and sacrococcygeal eversion. The patient shows facial dysmorphism with macrocephaly, dolichocephaly, and trigonocephaly, and an asymmetric skull, bilateral and severe exophthalmia with shallow orbits and ocular hypertelorism, downslanting palpebral fissures, constant strabismus, short anterior cranial base, and midface hypoplasia. CONCLUSIONS: Molecular analysis of the FGFR2 gene in this patient revealed a point mutation (c.890G>C NM_000141). This mutation leads to the substitution of the residue tryptophan at position 290 to cysteine in the protein (p.Try290Cys). These data reinforce the hypothesis that the p.Trp290Cys mutation is more often associated with a severe and poor prognosis of PS. Furthermore they suggest that the presence of sacrococcygeal defects is not associated with any specific FGFR2 mutation.

Mutational screening of FGFR1, CER1, and CDON in a large cohort of trigonocephalic patients.

OBJECTIVE: Screen the known craniosynostotic related gene, FGFR1 (exon 7), and two new identified potential candidates, CER1 and CDON, in patients with syndromic and nonsyndromic metopic craniosynostosis to determine if they might be causative genes. DESIGN: Using single-strand conformational polymorphisms (SSCPs), denaturing high-performance liquid chromatography, and/or direct sequencing, we analyzed a total of 81 patients for FGFR1 (exon 7), 70 for CER1, and 44 for CDON. PATIENTS: Patients were ascertained in the Centro de Estudos do Genoma Humano in São Paulo, Brazil (n = 39), the Craniofacial Unit, Oxford, U.K. (n = 23), and the Johns Hopkins University, Baltimore, Maryland (n = 31). Clinical inclusion criteria included a triangular head and/or forehead, with or without a metopic ridge, and a radiographic documentation of metopic synostosis. Both syndromic and nonsyndromic patients were studied. RESULTS: No sequence alterations were found for FGFR1 (exon 7). Different patterns of SSCP migration for CER1 compatible with the segregation of single nucleotide polymorphisms reported in the region were identified. Seventeen sequence alterations were detected in the coding region of CDON, seven of which are new, but segregation analysis in parents and homology studies did not indicate a pathological role. CONCLUSIONS: FGFR1 (exon 7), CER1, and CDON are not related to trigonocephaly in our sample and should not be considered as causative genes for metopic synostosis. Screening of FGFR1 (exon 7) for diagnostic purposes should not be performed in trigonocephalic patients.