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Objective To report and discuss the observation of three fragments on polymerase chain reaction (PCR) in routine carrier screening for fragile X. Methods From 2005 through 2010, 34,500 women underwent prenatal screening for fragile X. PCR was carried out to amplify the repeat segment. The resulting fragments were scanned by a genetic analyser. Results Three PCR peaks representing three different-sized fragments were found in 25 of the 34,500 women (1:1380 or 0.072%). Karyotype analysis was performed in 16 subjects. Full triple X was found in three women, while two had triple X mosaicism. Of the 16 karyotyped women, five (31%) had a finding of XXX (full or mosaic). Conclusions Triple X (full or mosaic) is the most frequently encountered mechanism responsible for three peaks on fragile X PCR testing.

Objective Velocardiofacial syndrome (VCFS) is the most common multiple anomaly disorder associated with palatal clefting. Cytogenetic hemizygous deletion of 22q11 region is found in 80% of patients. The frequency of 22q11 deletion in patients presenting with isolated palatal anomalies has not been fully assessed. Our objective was to determine the frequency of the deletion in patients with isolated palatal anomalies. Design Patients were referred because of velopharyngeal insufficiency because of isolated congenital palatal anomalies. Diagnosis of palatal anomalies was confirmed by videonasopharyngoscopy, multiview videofluoroscopy and cephalometry. Other clinical findings suggestive of VCFS were sought, and subjects with these characteristics were excluded from the study. Peripheral blood samples from all patients were analyzed cytogenetically utilizing fluorescent in situ hybridization for the 22q11 region. Results Thirty-eight patients aged 3 to 31 years were included in the study. Nine had cleft palate, 7 cleft lip and palate, 10 overt and 11 occult submucous cleft palate, and 1 had a deep nasopharynx. No deletion of 22q11 region was detected in any of the evaluated patients. Conclusions A routine screening for the 22q11 deletion in older children and adults presenting with an isolated palatal anomaly may not be required. Because other signs related to VCFS such as facial dysmorphism and behavioral or psychiatric disorders may evolve at an older age, young patients should be followed up and reevaluated for additional relevant symptoms that may lead to deletion evaluation. In light of the fact that the current literature is inconsistent, the relative small size of this study and the significant consequences of missed 22q11.2 deletion, more information is needed before definitive recommendations can be made.