Osteogenesis imperfecta type IV: prenatal molecular diagnosis and genetic counseling in a pregnancy carried to full term with favorable outcome

Dental alterations on panoramic radiographs of patients with osteogenesis imperfecta in relation to clinical diagnosis, severity, and bisphosphonate regimen aspects: a STROBE-compliant case-control study

OBJECTIVE

This study aimed to assess the prevalence of dental findings on panoramic radiographs (PRs) of patients with osteogenesis imperfecta (OI) and correlate these results with epidemiologic and medical data.

STUDY DESIGN

A case-control study was conducted with 24 patients with OI and 48 sex- and age-matched controls. Demographic, clinical, and bisphosphonate regimen-related data were recorded. The outcome variables were the presence or absence of dental alterations in PRs. Mann-Whitney U test, Pearson's χ² test, and multinomial logistic regression analysis (95% confidence interval) were used (significance level of 5%).

RESULTS

OI type 4 demonstrated a high prevalence (62.5%), followed by type 1 (37.5%). With regard to prevalence associated with severity, the moderate form was the most prevalent (P = .028). The mean time of intravenous pamidronate regimen was 6.6 ± 4.4 years. Dentinogenesis imperfecta was observed in 75% of patients with OI, and this group showed a high prevalence of dental abnormalities in comparison with controls (P < .05). Bisphosphonate therapy was associated with ectopic teeth (P = .007) and tooth impaction (P = .033). Pulp obliteration was significant with bisphosphonate treatment over a period of 7 years (P = .026).

CONCLUSIONS

This study found a significant prevalence of dental alterations in patients with OI, and certain alterations were associated with bisphosphonate therapy, indicating its influence on the dentin-related physiopathology.

Osteogenesis imperfecta Type IV: a newly identified variant at position c.560 (G > T; p.Gly187Val) in the COL1A2 gene

Osteogenesis imperfecta is a clinically heterogenous disease caused by defective collagen syntesis associated with a mutation in the COL1A1 or COL1A2 genes. In this report, we present a case of osteogenesis imperfecta (OI) type IV, seen in a female fetus with incurved femurs at 18 weeks of gestation. Molecular analysis of the newborn revealed a novel mutation at position c.560 (c.560 G > T) of the exon 12 in the COL1A2 gene; which lead to the glycine modification with valine (p.Gly187Val) at codon 187. The pregnancy follow-up was uneventful. After delivery, the newborn underwent biphosponat therapy and no fracture was detected until 1 year old.

Clinical application of antenatal genetic diagnosis of osteogenesis imperfecta type IV

Background

Clinical analysis and genetic testing of a family with osteogenesis imperfecta type IV were conducted, aiming to discuss antenatal genetic diagnosis of osteogenesis imperfecta type IV.

Material/Methods

Preliminary genotyping was performed based on clinical characteristics of the family members and then high-throughput sequencing was applied to rapidly and accurately detect the changes in candidate genes.

Results

Genetic testing of the III5 fetus and other family members revealed missense mutation in c.2746G>A, pGly916Arg in COL1A2 gene coding region and missense and synonymous mutation in COL1A1 gene coding region.

Conclusions

Application of antenatal genetic diagnosis provides fast and accurate genetic counseling and eugenics suggestions for patients with osteogenesis imperfecta type IV and their families.

Clinical aspects, imaging features, and considerations on bisphosphonate-related osteonecrosis risk in a pediatric patient with osteogenesis imperfecta

Osteogenesis imperfecta (OI) is a rare hereditary condition caused by changes in collagen metabolism. It is classified into four types according to clinical, genetic, and radiological criteria. Clinically, bone fragility, short stature, blue sclerae, and locomotion difficulties may be observed in this disease. OI is often associated to severe dental problems, such as dentinogenesis imperfecta (DI) and malocclusions. Radiographically, affected teeth may have crowns with bulbous appearance, accentuated constriction in the cementoenamel junction, narrowed roots, large root canals due to defective dentin formation, and taurodontism (enlarged pulp chambers). There is no definitive cure, but bisphosphonate therapy is reported to improve bone quality; however, there is a potential risk of bisphosphonate-related osteonecrosis of the jaw. In this study we report a case of OI in a male pediatric patient with no family history of OI who was receiving ongoing treatment with intravenous perfusion of bisphosphonate and who required dental surgery. In addition, we discussed the clinical and imaging findings and briefly reviewed the literature.