A new case of osteogenesis imperfecta type VIII and retinal detachment.

Osteogenesis imperfecta (OI) type VIII (OMIM: 610915) is a rare autosomal recessive disorder characterized by white sclerae, severe growth deficiency, and bone fragility. This condition results from pathogenic variants of P3H1, a gene that codes for P3H1, an important protein involved in the prolyl-3-hydroxylation complex required for collagen type I folding. Here, we described a woman with OI type VIII due to a homozygous mutation of c.1914+1G>C (NM_001243246.1) in P3H1 and retinal detachment. We compared our case to five severe OI and retinal detachment cases reported in the literature. The only case previously reported with a molecular diagnosis had a similar mutation in P3H1 c.1914+1G>A and a giant retinal detachment. We suggest that individuals with OI type VIII should be submitted to careful fundoscopic examination.

Collagen I Defect Corneal Profiles in Osteogenesis Imperfecta.

PURPOSE: The goal of this study was to evaluate corneal profiles of patients with osteogenesis imperfecta (OI) due to a collagen I gene mutation. METHODS: This was a cross-sectional comparative study. There were 84 eyes from 42 patients with OI types I, III, and IV who were recruited from the OI Clinic at the Clinical Hospital of Porto Alegre, Brazil. All cases presented either COL1A1 or A2 gene mutations. Controls were matched by sex, age, and refractive error. Corneal Scheimpflug tomography was used to determine curvature and thickness parameters in both groups. RESULTS: Quantitative collagen mutations were found only in OI type I. Qualitative mutations were responsible for all mutations observed in type III and IV patients. Each OI type presented significantly lower pachymetric values at the thinnest point compared with controls (443.7-505.1 vs. 541.9-548.5 µm; P < 0.001). In addition, significantly lower pachymetric values were observed in patients with OI compared with controls in all positions between the central and corneal periphery (581.4-657.0 vs. 704.5-720.7 µm at an 8.0-mm-diameter circle; P < 0.001). Differences in anterior and posterior radii of curvatures, respectively, between patients with OI and controls were not statistically significant (7.64-7.80 vs. 7.65-7.69 mm; P > 0.05) except for a lower anterior radii of curvatures in type III (7.33 vs. 7.72 mm; P < 0.01). CONCLUSIONS: Although patients with OI have homogenously thinner corneas compared with controls, we observed that a collagen I chain mutation was not responsible for corneal curvature alterations in OI.

A multicentric association study between 39 genes and nonsyndromic cleft lip and palate in a Brazilian population.

PURPOSE: The aim of this study was to use the TaqMan OpenArray system to evaluate associations between 39 genes and the etiology of nonsyndromic cleft lip and palate (NSCLP) in a Brazilian population. MATERIAL AND METHODS: This case-control association study was designed with 80.11% statistical power according to logistic regression (GPOWER software). The case group had 182 patients with NSCLP enrolled in the Brazilian Database on Orofacial Clefts. The controls included 355 healthy individuals with no history of oral clefting in the past three generations. All samples were genotyped for 253 tag single nucleotide polymorphisms (tagSNPs) in 39 genes, including two that had recently been associated with this process. The association analysis was performed using logistic regression and stepwise regression. The results were corrected for multiple testing [Bonferroni correction and False Discovery Rate (FDR)]. RESULTS: Twenty-four SNPs in 16 genes were significantly associated with the etiology of NSCLP, including MSX1, SPRY1, MSX2, PRSS35, TFAP2A, SHH, VAX1, TBX10, WNT11, PAX9, BMP4, JAG2, AXIN2, DVL2, KIF7, and TCBE3. Stepwise regression analysis revealed that 11 genes contributed to 15.5% of the etiology of NSCLP in the sample. CONCLUSION: This is the first study to associate KIF7 and TCEB3 with the etiology of NSCLP. New technological approaches using the same design should help to identify further etiological susceptibility variants.

Preliminary Analysis of the Nonsynonymous Polymorphism rs17563 in BMP4 Gene in Brazilian Population Suggests Protection for Nonsyndromic Cleft Lip and Palate.

Cleft lip with or without palate (CL±P) is common congenital anomalies in humans. Experimental evidence has demonstrated that bone morphogenetic protein 4 gene (Bmp4) is involved in the etiology of CL±P in animal models. The nonsynonymous polymorphism rs17563 T>C (p.V152A) in the BMP4 gene has been associated to the risk of nonsyndromic CL±P in Chinese population and microforms from different ethnic backgrounds. The aim of this study was to investigate the role of BMP4 gene in CL±P in Brazilian sample using genetic association approach. Our sample was composed by 123 patients with nonsyndromic CL±P and 246 controls, in which absence of CL±P was confirmed in 3 generations. The rs17563 polymorphism was genotyped by PCR-RFLP technique. Logistic regression was performed to evaluate allele and genotype association. Our data showed statistical power to detect association (86.83%) in this sample. Logistic regression results showed significant association between C allele and CL±P (P = 0.00018, OR = 0.40, and 95% CI = 0.25-0.65), as well as CC genotype and CL±P (P = 0.00018, OR = 0.35, and 95% CI = 0.19-0.66). So, there is a strong association between nonsyndromic CL±P and BMP4 rs17563 polymorphism in our sample and the C allele had a protective effect against the occurrence of nonsyndromic CL±P.

Prevalence of the 35delG mutation in deaf South Brazilian infants submitted to cochlear implantation.

OBJECTIVE: Determine the prevalence of 35delG mutation in GJB2 gene in patients with prelingual deafness of no defined etiology whose underwent cochlear implant in the Otolaryngology Department at the Hospital de Clínicas de Porto Alegre and compare the speech recognition index using an open-set of sentences according to the presence or absence of the 35delG mutation. METHODS: Cross-sectional study nested in a cohort. Were analyzed 37 patients with indeterminate etiology for deafness that underwent to cochlear implant. DNA was extracted and the mutations were studied using Polymerase Chain Reaction followed by gene sequencing. RESULTS: The prevalence of 35delG mutation was 11%. The speech recognition index was 72% in the group with 35delG mutation, and 30% in the group without this mutation (p>0.05). CONCLUSIONS: Prevalence of 35delG mutation in this study confirmed findings in the Brazilian literature. There was a clinically significant difference in hearing performance in patients with 35delG. Absence of statistical significance in this result might be attributed to the small number of patients with 35delG in our sample.