OBJECTIVE: To explore the genetic etiology of 46 Chinese pedigrees affected with Hereditary multiple exostoses (HME) and provide genetic counseling and reproductive intervention. METHODS: Whole-exome sequencing and Sanger sequencing were carried out on 87 patients from the 46 pedigrees to analyze the variants of EXT1 and EXT2 genes. Pathogenicity of the variants was assessed based on the guidelines from the American College of Medical Genetics and Genomics and Association for Molecular Pathology (ACMG/AMP). Prenatal diagnosis and preimplantation genetic testing (PGT) were provided for couples with identified pathogenic mutations. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: LL-SC-SG-2014-010). RESULTS: In total 17 and 22 pathogenic variants were respectively identified in the EXT1 and EXT2 genes, among which 5 EXT1 and 12 EXT2 variants were unreported previously. Three patients with no family history were found to harbor de novo variants of the EXT1 gene. Twenty nine couples had opted for PGT or underwent prenatal diagnosis following natural conception, and 17 healthy babies were born. CONCLUSION This study has clarified the genetic etiology of 45 HME pedigrees and identified 17 novel variants, which has enriched the mutational spectrum of the EXT1 and EXT2 genes. Reproductive intervention through PGT and prenatal diagnosis have prevented the recurrence of HME in these families.
Humans ; Female ; Male ; Pedigree ; Exostoses, Multiple Hereditary/diagnosis* ; N-Acetylglucosaminyltransferases/genetics* ; Adult ; Exostosin 1 ; Asian People/genetics* ; Genetic Testing ; Exostosin 2 ; Mutation ; China ; Prenatal Diagnosis ; Pregnancy ; Genetic Counseling ; Preimplantation Diagnosis ; Exome Sequencing ; East Asian People

Lange-Giedion syndrome, or trichorhinophalangeal syndrome type 2 (TRPSII), is a clinical syndrome characterized by mild growth restriction, mental retardation, microcephaly and dysmorphic face. Bulbous nose, large protruding ears and loose redundant skin are distinguishing features, as well as lax joints and phalangeal abnormalities of the hands and multiple exostoses. TRPS1 and EXT1 gene deletion are responsible for this. Diagnosis is mainly based on clinical and radiographic features. In Korea, no cases of this disease have been reported thus far. Along with a review of the literature, we report a case of TRPSII in a neonate who had peculiar face representing TRPSII, polydactyly, Mullerian duct cyst, and ptosis and was found to have an interstitial deletion of 8q23-24.1.
Diagnosis ; Ear ; Exostoses, Multiple Hereditary ; Gene Deletion ; Hand ; Humans ; Infant, Newborn ; Intellectual Disability ; Joints ; Korea ; Langer-Giedion Syndrome* ; Microcephaly ; Nose ; Polydactyly ; Skin

Potocki-Shaffer syndrome (PSS, OMIM #601224) is a rare contiguous gene deletion syndrome caused by haploinsufficiency of genes located on the 11p11.2p12. Affected individuals have a number of characteristic features including multiple exostoses, biparietal foramina, abnormalities of genitourinary system, hypotonia, developmental delay, and intellectual disability. We report here on the first Korean case of an 8-yr-old boy with PSS diagnosed by high resolution microarray. Initial evaluation was done at age 6 months because of a history of developmental delay, hypotonia, and dysmorphic face. Coronal craniosynostosis and enlarged parietal foramina were found on skull radiographs. At age 6 yr, he had severe global developmental delay. Multiple exostoses of long bones were detected during a radiological check-up. Based on the clinical and radiological features, PSS was highly suspected. Subsequently, chromosomal microarray analysis identified an 8.6 Mb deletion at 11p11.2 [arr 11p12p11.2 (Chr11:39,204,770-47,791,278)x1]. The patient continued rehabilitation therapy for profound developmental delay. The progression of multiple exostosis has being monitored. This case confirms and extends data on the genetic basis of PSS. In clinical and radiologic aspect, a patient with multiple exostoses accompanying with syndromic features, including craniofacial abnormalities and mental retardation, the diagnosis of PSS should be considered.
Child ; Chromosome Deletion ; Chromosome Disorders/diagnosis/*genetics/radiography ; Chromosome Mapping ; Chromosomes, Human, Pair 11/genetics/radiography ; Craniofacial Abnormalities/genetics ; Developmental Disabilities/genetics ; Exostoses, Multiple Hereditary/diagnosis/*genetics/radiography ; Humans ; Male ; Muscle Hypotonia/genetics ; Oligonucleotide Array Sequence Analysis ; Rare Diseases/*genetics ; Republic of Korea

Potocki-Shaffer syndrome (PSS, OMIM #601224) is a rare contiguous gene deletion syndrome caused by haploinsufficiency of genes located on the 11p11.2p12. Affected individuals have a number of characteristic features including multiple exostoses, biparietal foramina, abnormalities of genitourinary system, hypotonia, developmental delay, and intellectual disability. We report here on the first Korean case of an 8-yr-old boy with PSS diagnosed by high resolution microarray. Initial evaluation was done at age 6 months because of a history of developmental delay, hypotonia, and dysmorphic face. Coronal craniosynostosis and enlarged parietal foramina were found on skull radiographs. At age 6 yr, he had severe global developmental delay. Multiple exostoses of long bones were detected during a radiological check-up. Based on the clinical and radiological features, PSS was highly suspected. Subsequently, chromosomal microarray analysis identified an 8.6 Mb deletion at 11p11.2 [arr 11p12p11.2 (Chr11:39,204,770-47,791,278)x1]. The patient continued rehabilitation therapy for profound developmental delay. The progression of multiple exostosis has being monitored. This case confirms and extends data on the genetic basis of PSS. In clinical and radiologic aspect, a patient with multiple exostoses accompanying with syndromic features, including craniofacial abnormalities and mental retardation, the diagnosis of PSS should be considered.
Child ; Chromosome Deletion ; Chromosome Disorders/diagnosis/*genetics/radiography ; Chromosome Mapping ; Chromosomes, Human, Pair 11/genetics/radiography ; Craniofacial Abnormalities/genetics ; Developmental Disabilities/genetics ; Exostoses, Multiple Hereditary/diagnosis/*genetics/radiography ; Humans ; Male ; Muscle Hypotonia/genetics ; Oligonucleotide Array Sequence Analysis ; Rare Diseases/*genetics ; Republic of Korea

Hereditary multiple exostoses (HME) are an autosomal dominant skeletal disease with wide variations in clinical manifestations among different ethnic groups. This study investigated the epidemiology, clinical presentations, pathogenetic features and treatment strategies of HME in mainland China. We searched and reviewed the related cases published since 1990 by searching electronic databases, namely SinoMed database, Wanfang database, CNKI, Web of Science and PubMed as well as Google search engines. A total of 1051 cases of HME (male-to-female ratio 1.5:1) were investigated and the diagnosis was made in 83% before the age of 10 years. Approximately 96% patients had a family history. Long bones, ribs, scapula and pelvis were the frequently affected sites. Most patients were asymptomatic with multiple palpable masses. Common complications included angular deformities, impingement on neighbouring tissues and impaired articular function. Chondrosarcomas transformation occurred in 2% Chinese cases. Among the cases examined, about 18% had mutations in EXT1 and 28% in EXT2. Frameshift, nonsense and missense mutations represented the majority of HME-causing mutations. Diagnosis of HME was made based on the clinical presentations and radiological documentations. Most patients needed no treatment. Surgical treatment was often directed to remove symptomatic exostoses, particularly those of suspected malignancy degeneration, and correction of skeletal deformities. This study shows some variance from current literature regarding other ethnic populations and may provide valuable baseline assessment of the natural history of HME in mainland China.
Adult ; Asian Continental Ancestry Group ; genetics ; Cell Transformation, Neoplastic ; genetics ; China ; epidemiology ; Exostoses, Multiple Hereditary ; diagnosis ; ethnology ; genetics ; Family Health ; Female ; Genetic Predisposition to Disease ; genetics ; Humans ; Male ; Membrane Proteins ; genetics ; Middle Aged ; Mutation ; N-Acetylglucosaminyltransferases ; genetics ; Polymorphism, Genetic ; Prevalence ; Retrospective Studies ; Sex Factors ; Tumor Suppressor Proteins ; genetics ; Young Adult

OBJECTIVETo screen for potential mutations in an ethnic Han Chinese family from Shanxi with hereditary multiple exostoses.

METHODSPolymerase chain reaction and DNA sequencing were used to screen potential mutations in EXT1 and EXT2 genes.

RESULTSFor EXT1 gene, two synonymous mutations (P477P and E587E), three intronic mutations (c.1537 -48A>G, c.1721 +203A>G and c.1722 -103C>G) were detected. For EXT2 gene, five intronic mutations (c.-29 -148A>T, c.1080 -18T>A, c.1336 -93C>T, c.1526 -166C>T, and c.1526 -195C>T) were identified. Among these, EXT1 P477P, EXT1 E587E and EXT2 c.1080 -18T>A are polymorphisms listed by Multiple Osteochondroma Mutation Database, whilst the other 7 sites have not been reported.

CONCLUSIONNo mutations have been found among all exons of the EXT1 and EXT2 genes in this family. Linkage analysis is necessary for identifying the cause of this disease.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; Child ; Child, Preschool ; China ; Exons ; Exostoses, Multiple Hereditary ; diagnosis ; genetics ; Female ; Genotype ; Humans ; Introns ; Male ; Middle Aged ; Mutation ; N-Acetylglucosaminyltransferases ; genetics ; Young Adult

OBJECTIVETo identify the genetic cause for a Chinese Han family affected with hereditary multiple osteochondromas.

METHODSTwo patients, five unaffected relatives of the family and 100 unrelated healthy controls were collected. The coding sequences and intron/exon boundaries of EXT1 gene were amplified with polymerase chain reaction (PCR) and sequenced.

RESULTSA heterozygous c.600G>A (p.Trp200X) mutation in exon 1 of the EXT1 gene was detected in the patients. The same mutation was not found in unaffected family members and 100 healthy controls.

CONCLUSIONThe hereditary multiple osteochondromas in the family is caused by a nonsense mutation (p.Trp200X) in the EXT1 gene.

Asian Continental Ancestry Group ; genetics ; Child ; Exostoses, Multiple Hereditary ; diagnosis ; genetics ; Female ; Heterozygote ; Humans ; Male ; Mutation ; N-Acetylglucosaminyltransferases ; genetics ; Pedigree

The aim of this paper is to show that osteochondromas of the cervical vertebrae can cause myelopathy and neck pain.The reported etiology, diagnosis, treatment and differential diagnosis were reviewed. Osteochondromas may present as a solitary lesion with no genetic component or as multiple lesions as a part of a genetic disorder known as hereditary multiple exostosis. Osteochondromas of the spine are rarely encountered in clinical practice. These lesions are reported more commonly with neural compression in cases associated with hereditary multiple exostosis. The authors describe a unusual clinical manifestation of a solitary osteochondroma located in the right posterior arch of the atlas. Complete removal of the tumor was performed resulting in the relief of neck pain and spastic quadriparesis. Although unusual, osteochondromas of the cervical spine must be considered in patients with persistent neck pain and progressive symptoms of myelopathy. Computed tomography and magnetic resonance imaging in conjunction with plain radiograms is the neuroradiological modality of choice. The diagnosis and surgical excision of these tumors are important because they can cause spinal stenosis resulting in neural tissue compression and myelopathy.
Cervical Vertebrae ; Diagnosis, Differential ; Exostoses, Multiple Hereditary ; Female ; Humans ; Magnetic Resonance Imaging ; Muscle Spasticity ; Neck ; Neck Pain ; Osteochondroma ; Quadriplegia ; Spinal Cord ; Spinal Cord Compression ; Spinal Cord Diseases ; Spinal Stenosis ; Spine

OBJECTIVETo explore the clinicopathologic features of Ollier's disease, its chondrosarcomatous transformation and related differential diagnoses.

METHODSA total of 19 cases of Ollier's disease and 8 control cases of pure multiple enchondroma were investigated by imaging studies including X-ray, CT or MRI, and hematoxylin and eosin stain.

RESULTSAmong 19 cases of Ollier's disease, 12 were men and 7 were women with a mean age of 20 years (range, 5-66 years). Ollier's disease involving short tubular bones of extremity were lytic defects with bony expansion, thinning or disappearance of the overlying cortex surrounded by periosteal fibrous tissues. When occurring in the long bones, the disease showed radiolucent columns of dysplastic cartilage that extended from the metaphysis to diaphyseal and created bowing deformation and limb asymmetry. Microscopically, the cartilage present in the small bones of the hands and feet tended to be more hypercellular with more abundant enlarged or binucleated nuclei. The lesion in long bones appeared multicentric, surrounding with a thin rim of bone and calcification. Six cases of Ollier's disease had developed secondary low-grade chondrosarcoma.

CONCLUSIONSLow-grade chondrosarcomatous transformation can occur in dysplastic cartilage of Ollier's disease. The diagnosis of such sarcomatous transformation should be determined by invasion, but not atypicality of the cartilagenous cells. There are certain differences between the secondary chondrosarcoma of Ollier's disease and conventional chondrosarcoma on clinical, radiographical and pathological grounds.

Adolescent ; Adult ; Aged ; Bone Neoplasms ; diagnostic imaging ; etiology ; pathology ; surgery ; Cell Transformation, Neoplastic ; Child ; Chondrosarcoma ; diagnostic imaging ; etiology ; pathology ; surgery ; Diagnosis, Differential ; Enchondromatosis ; complications ; diagnostic imaging ; pathology ; surgery ; Exostoses, Multiple Hereditary ; pathology ; Female ; Humans ; Male ; Middle Aged ; Radiography ; Young Adult

OBJECTIVE: To detect the mutations of EXT2 gene in hereditary multiple exostoses (HME) families and to investigate the sensitivity of denaturant gradient gel electrophoresis (DGGE) in screening the mutations in EXT2 gene. METHODS: Five HME families and 3 sporadic patients were screened for the mutation detection in all exons of EXT2 gene covering the coding sequence and the flanking intronic sequence by DGGE, and DNA sequencing was performed for products with abnormal conformation. RESULTS: Among these HME patients, we found 2 disease-causing mutations: A313T (nonsense mutation) and 319 insGT (frameshift mutation). CONCLUSION Two mutations of EXT2 gene are identified in the sample. DGGE can be an ideal choice for gene diagnoses of HME.
Adolescent ; Adult ; Base Sequence ; Child ; DNA Mutational Analysis ; Electrophoresis, Polyacrylamide Gel ; methods ; Exons ; Exostoses, Multiple Hereditary ; diagnosis ; genetics ; Female ; Genes, Tumor Suppressor ; Humans ; Male ; Middle Aged ; Mutation ; N-Acetylglucosaminyltransferases ; genetics