Treatment And Preliminary Pathogenesis Research Of Hereditary Multiple Osteochondroma (HME)

First part The clinical study of special types of hereditary multiple osteochondroma(HME)Objective: To perform the Clinical treatment,histopathology and family studies of a rare case of hereditary multiple exostoses which was found in clinical work.The tumor of which is large and malignant.Collect the tumor specimens,study their clinical pathological types and verify the existence of malignant change and then sketch out the family genetic map.Methods: A special patient of hereditary multiple exostoses were found in clinical work,the patient's knee,ankle and other multiple tumors,especially the tumor in the right chest,armpits and shoulder,basketball sized and have growing for many years,in recent years the growth speed accelerated,through medical history study,we found that most of the family members are in a similar situation,thus a genetic illustration map will be drew;complete the hospitalized patients' physical examination and preoperative examination and then make sure the surgical plan is perfect,the proband underwent surgery;resection of tumor tissue for pathological examination;the tumor tissue cut into appropriate size fixed,paraffin embedded,and then in sections,HE staining on glass slides,observed by microscope and then take the pathological image.Results: Family history investigation confirmed that this is a hereditary multiple osteochondroma family,the patient who take the treatment is a pro-band,who live a life in the Northern Village of An Hui Province,the environment is relatively closed,there are 8 people with the disease in the four generation,the big family totally have 28 people,while the other families or their members have no similar disease.The HME family have a obvious genetic characteristics,tumor genes are biologically active,the pro-band grandfather died of similar tumors,the pro-band's father has a multiple tumor body,ankle,knee joint destruction,tumor base wide,and has a clinical manifestation of malignancy;the pro-band's pre-operation examination are all finished and the operation undergone smoothly,during the surgery we find the tumor tissue is huge,spreading to the right chest,armpits and scapular,the character is hard,and the surface is rough,the normal tissue on the surrounding(such as nerve,blood vessels,normal bone tissue)have an abnormal performance caused by different degree of compression.The postoperative pathological results confirmed that the patient(pro-band)was osteochondroma.Some of the tumor tissue had chondrosarcoma like transformation.Conclusion: Hereditary multiple exostoses(HME)found in this project is very different than other families,mainly in: The incidence rate is higher,the size of tumor is large,the growth of osteochondroma has a malignancy tendency,which informed us that the family is very different than others ever found,there may be a strong or unknown pathogenic gene causing the disease.Second part The study on the pathogenic geneObjective: Through the process of clinical work,we found and genetic research a rare case of malignant hereditary multiple exostoses(HME),and compared to the hereditary multiple exostoses known pathogenic genes,explore the corresponding pathogenic mechanism.Methods: Under the consent of the pro-band,parents of pro-band(father with the disease and mother was a normal person)and pro-bands uncle(patient)agree,selected 4 peripheral blood and extract genomic DNA,then EXT-1 and EXT-2 of each exon was amplified by PCR;amplified the EXT-1 and EXT-2 of these exons and then sequenced by Sanger to confirm that the EXT1 and EXT2 gene encoding sequence are normal or mutation;further detect the pro-band,parents of pro-band(father was a patient,the mother was a normal person)in peripheral blood and tumor tissue of patients with EXT-1 and EXT-2 promoter methylation status,thus proving these two gene promoter methylation exists;whole genome sequencing for the pro-band,his father and mother blood cell genomic DNA and pro-band genomic DNA of tumor.Take bio-information analysis of mutant genes of the pro-band peripheral blood,tumor tissues and peripheral blood of his father,according to the conservation of mutation sites in the genome sequence and corresponding amino acid to these mutations,calculate and evaluate the changes of protein structure and functional caused by mutations.With reference to the mutation frequency of each gene in the genome of the human genome project,analysis the information of mutant genes by signal pathway enrichment.Results: The coding region of EXT1 and EXT2 gene was sequenced in many patients.Methylation of the promoter region of these two genes was detected,and no abnormality was found.Therefore,in this HME family,the expression of EXT1-2 gene in the wild type,which provides a rare clinical material for the screening of new pathogenic genes of HME.Subsequently,we sequenced the whole genome of several samples of this family of two generations.The results showed that the degradation pathway of 4-hydroxylproline was significantly abnormal,mainly in the mutation of HOGA-1 gene.Conclusion: The genetic diversity of hereditary multiple osteochondroma is complex,and there is really exist EXT wild HME gene in patients with HME,and the patients without EXT mutation are more likely to develope more serious disease and even malignant transformation.Study on the part of pedigree samples,the results show that the 4-hydroxy-2-ketoglutaric acid aldolase gene(HOGA-1)was abnormal,suggesting that the 4-signaling pathway and its key hydroxyproline HOGA-1 gene mutation may be a new hereditary multiple exostoses(HME)pathogenesis.