Linkage disequilibrium analysis of two genes mapping on OFC3: PVR and PVRL2.

Clefts of the lip with or without cleft palate (CL/P) are one of the most common birth defects, occurring in 1/700-1/1,000 infants born alive. The nature of the genetic contribution is still to be clarified; however, some chromosome regions and candidate genes have been proposed for this malformation. Recently, a couple of genes, PVR and PVRL2, mapping in the candidate region OFC3 on chromosome 19q13.31, have been investigated because of their homology to PVRL1, a gene previously shown to cause the Margarita Island CL/P-ectodermal dysplasia syndrome. In the present work, we investigated PVR and PVRL2 genes by family-based linkage disequilibrium analysis using a sample collected from the Italian population. In contrast to previous analyses on other populations, we could not find any statistically significant association between the markers alleles and non-syndromic clefting.

Study of four genes belonging to the folate pathway: transcobalamin 2 is involved in the onset of non-syndromic cleft lip with or without cleft palate.

Cleft lip with or without cleft palate (CL/P) is the most common inborn craniofacial anomaly. Affected individuals require extensive medical and psychosocial support. Although CL/P has a complex and poorly understood etiology, increasing evidence of folate pathway involvement has been collected. So far, only the MTHFR gene has been extensively investigated as a risk factor for CL/P, while little has been done to test genetic variations in the folate biosynthetic pathways that may influence the infant's susceptibility to these birth defects. To date, this paper presents the first attempt to verify the involvement of four genes belonging to the folate pathway in nonsyndromic cleft onset. We used a case-parent triad design to test for linkage disequilibrium in the case of seven SNPs mapping on four different genes: transcobalamin 1 and 2 (TCN1 and TCN2), methionine synthase (MTR), and MTR reductase (MTRR). Our finding suggests that TCN2 is involved in causing CL/P. Indeed, significant overtransmission of the C allele was observed at the polymorphism c.776C>G (p.Pro259Arg) to the affected offspring (P=0.01). Results obtained with additional TCN2 polymorphisms suggest that c.776C>G may be functionally related to CL/P. However, because conflicting data exist with regard to the effect of the polymorphism in transcobalamin 2 function or in perturbing plasma levels of key molecules in the folate pathway, further investigation is warranted to confirm our data.

Parosteal chondrosarcoma, a very rare condition of the mandibular condyle.

We present a rare case of parosteal chondrosarcoma of the madibular condyle. The patient was referred for a functional limitation of the left temporo-mandibular joint. CT and MRI examinations demonstrated a 3.5-cm cystic mass with a peripheral rim of contrast enhancement located in the left pterygo-maxillary space. The mass had partial intraarticular spread causing deformation and focal cortical erosion of the medial aspect of the condylar head. The lesion was surgically removed; the histological diagnosis was of low-grade chondrosarcoma.

Prophylaxis with cefazolin plus clindamycin in clean-contaminated maxillofacial surgery.

PURPOSE: Infections after maxillofacial surgery are usually due to aerobic and anaerobic gram-positive cocci and gram-negative bacilli. Various antimicrobials, including cephalosporins, beta-lactams/beta-lactamase inhibitors, aminoglycosides, lincosamides, and fluoroquinolones, have been tested for use for perioperative prophylaxis in maxillofacial surgery. However, the best regimen has not been determined. We tested the safety and the efficacy of clindamycin plus cefazolin as perioperative prophylaxis for patients undergoing major maxillofacial procedures. PATIENTS AND METHODS: Intravenous cefazolin and clindamycin in 3 doses were administered to 155 patients undergoing major maxillofacial procedures. After surgery, patients were monitored for the presence of infection and side effects. RESULTS: No patient experienced a fever or infection after surgery. No side effects related to these antibiotics were observed. CONCLUSIONS: The antibiotics used as prophylaxis in maxillofacial surgery should possess an adequate coverage against gram-positive aerobic and anaerobic cocci as well as gram-negative bacilli. Prophylaxis with cefazolin plus clindamycin in major maxillofacial seems safe and effective.

Recent developments in orofacial cleft genetics.

Nonsyndromic cleft of the lip and/or palate (CLP or orofacial cleft) derives from an embryopathy with consequent failure of the nasal process and/or palatal shelves fusion. This severe birth defect is one of the most common malformations among live births. Nonsyndromic CLP is composed of two separate entities: cleft lip and palate (CL+/-P) and cleft palate only (CPO). Both have a genetic background, and environmental factors probably disclose these malformations. In CL+/-P, several loci have been identified, and, in one case, a specific gene has also been found. In CPO, one gene has been identified, but many more are probably involved. Because of the complexity of the genetics of nonsyndromic CLP as a result of the difference between CL+/-P and CPO, heterogeneity of each group caused by the number of involved genes, type of inheritance, and interaction with environmental factors, we discuss the more sound results obtained with different approaches: epidemiological studies, animal models, human genetic studies, and in vitro studies.