[Application of optical genome mapping technology for the detection of chromosomal structural variations].

OBJECTIVE: To assess the value of optical genome mapping (OGM) for the detection of chromosomal structural abnormalities including ring chromosomes, balanced translocations, and insertional translocations. METHODS: Clinical data of four patients who underwent pre-implantation genetic testing concurrently with OGM and chromosomal microarray analysis at the Center of Reproductive Medicine of the Sixth Affiliated Hospital of Sun Yat-sen University from January to October 2022 due to chromosomal structural abnormalities were selected as the study subjects. Some of the results were verified by multi-color fluorescence in situ hybridization. RESULTS: The OGM has successfully detected a balanced translocation and fine mapped the breakpoints in a patient. Among two patients with insertional translocations, OGM has provided more refined breakpoint locations than karyotyping analysis in a patient who had chromosome 3 inserted into chromosome 6 and determined the direction of the inserted fragment. However, OGM has failed to detect the chromosomal abnormality in a patient with chromosome 8 inserted into the Y chromosome. It has also failed to detect circular signals in a patient with ring chromosome mosaicism. CONCLUSION: OGM has successfully detected chromosomal structural variations in the four patients and provided assistance for their diagnosis.

[Subarea ostectomy of mandible for lower face re-shaping].

OBJECTIVE: Dividing the mandible into lower part of mandibular ramus, mandibular angle, mandibular body, chin, we designed subarea ostectomy for reduce the width of anterior, body, posterior part of of the lower face. METHODS: Combide with splitting ostectomy of the out layer of mandible, ostectomy of inferior border of mandible and augmentation of the chin, re-shape the mandibular angle, body, and chin, corrected the un-beauty of the lower face and side-face. RESULTS: From May 2003 to August 2005 , a total of twenty-three patients have been operated on by this method with satisfactory results. CONCLUSIONS: Subarea ostectomy of mandible is more effective in re-shaping the whole lower face.